From the outlet side of septic tank, effluent can flow downhill at a much steeper angle. Always ‘bed’ all pipe and tank well, in plenty of gravel. A 6-8 inch layer or 3/4 to 1 inch diameter aggregate is recommended. Generally, a conventional gravity septic system in Whatcom County consists of a two compartment septic tank (minimum 900 gallons). The drain field is generally a gravel type bed system consisting of a series of 4 drain pipes installed to ensure proper distribution within the gravel bed. How many trenches do we need for a septic system? Septic drainfield pipe hole or perforation position: up or down? As you see in the sketches shown here, the septic leaching bed perforated pipe is placed on a bed of gravel and then covered with more gravel.
The common types of septic systems are gravity, pressure distribution, sand filter, and mound systems. Within the sand fill is a gravel bed with a network of pressurized pipes. A properly designed and well-maintained septic system should provide decades of service. Driving or parking heavy vehicles over the leach field can break the perforated leach pipe, especially if it is not uniformly supported by the gravel bed. A Septic Tank, for solids and scum, and a Tile Bed for effluent to drain into. Most pipes are PVC plastic with a series of holes drilled in the bottom to allow the waste water to flow into the pipe and into the gravel surrounding the pipe.
Generally there are two types of conventional septic systems: those that use gravel in the drainfield and those that use some form of chamber system. Additional gravel is poured around and over the pipe, then the gravel is covered by a semipermeable barrier such as geotextile fabric so that backfill soil doesn’t filter between the rocks and reduce the field’s ability to absorb water. This allows some of the water to perculate into the ground below the ETA beds. Lay out and stake the locations of the feedline trench, septic tank, and pump chamber. If you have a septic tank you will need a septic tank drain field.
Types Of Septic Systems
Learn about your septic system so you can prolong its life and avoid costly breakdowns. This area, which must be kept free of trees and shrubs so their roots don’t damage it, consists of perforated pipes or drain tiles buried in trenches or set on a gravel bed one to three feet below the surface. Restore drainage to septic system drain field soil. They are installed in trenches or beds without gravel (except where local codes require the use of gravel). In a septic tank, liquid sewage goes through a physical settling process which is assisted by bacteria. Design your Mound System with 24 of Sand Under the Gravel Bed:. This page contains LOTS of information about septic system types, their history, etc. Within the sand fill is a gravel bed with a network of pressurized pipes. A malfunctioning well or septic system can pose a health risk to your family and neighbours, and can be expensive to repair or replace. This may be a system of trenches partially filled with a bed of washed gravel into which perforated or open joint pipe is placed. The discharge from the septic tank is distributed through these pipes into the trenches and surrounding soil.
Because many of these soils are unsuitable for conventional gravel trench absorption fields, two methods soil morphology evaluations and percolation tests are commonly used for sizing the absorption field. If a trench or bed depth of less than 18 inches is specified by the results of a soil morphology evaluation, shallow placement procedures should be followed ( Shallow placement of trenches section). The septic system consists of two parts, the septic tank and the drainfield. Together, they function to process plumbing wastes in a safe and sanitary manner. The total area of the gravel bed must be large enough to accommodate the gallons/hour put into the system against the absorption rate of the soil. The cesspool is the forerunner to the modern septic system. A seepage pit is similar to a cesspool in construction consisting of a large pit lined with concrete rings, or porous masonry block to support the walls of the pit, and a surrounding bed of gravel.