Skip to Content

Other Wastewater Systems

Wastewater systems come in many forms. While the most common is the septic system described above, there are alternatives. For various reasons, most often unacceptable soil characteristics, ledge or high ground water, several alternative systems have been developed. These include gray water systems, composting toilets, pressure-dosed systems, mound systems, and sand filters.

Gray Water Systems

In some areas, wastewater from laundry, bathtubs, and showers is called gray water and is diverted into secondary disposal systems. This can reduce the load on the septic tank and provide alternative wastewater disposal. In many parts of the United States and Canada, gray water systems are no longer legal. If a home you’re considering (or your own home) has a gray water system you should check to be sure that it complies with local ordinances. Also, you should determine what regular maintenance might be needed. Some gray water systems include the equivalent of a septic tank.

Composting Toilet Systems

There are a variety of systems that will compost the waste rather than process it through a traditional septic system. These are preferable where soil quality or geological characteristics prevent a traditional septic system, the property is close to a body of water, water for flushing is unavailable or expensive, or personal ecological priorities prefer this type of system. There are pros and cons to a composting system. Gray water and the composted waste must still be disposed of separately.

Pressure-Dosed System

The pressure-dosed system includes a pump chamber and pumps the effluent into the distribution field on prescribed dosage frequency. This is often more affective depending on the characteristics of the soil. It also requires more mechanical components.

Mound System

The mound system raises the distribution bed above ground water, bedrock and/or poor soils. In effect, it is creating a new layer of soil into which the effluent can drain. Typically, unless site characteristics are favorable, a mound system requires a pump, to pump effluent from the septic tank to the drainage field. Mound systems are effective but may impact the esthetics of the site by creating a large "mound" above the natural slope.

Sand Filters

Sand filters introduce an intermediate step in a typical septic system. Effluent is fed through the sand filter where bacteria digest the waste as the water percolates through that area. The treated, filtered effluent is then collected and flows to a drain field. Sand filters are affective in a variety of soil types and, in effect, purify the septic effluent before it goes to the drain field.

Criterium Engineers, Copyright © 1999