#Septic tank and drain field layout free#

In addition, it should be strong enough to withstand the Earth’s movements and hold the weight of the waste. Septic Tank ConstructionĪ septic tank construction should be perfect to prevent cracking and groundwater pollution. However, due to the total volume requirement for sludge and scum accumulation, a septic tank is designed for a detention period of not less than 48 hours. The minimum sewage detention period in a septic tank is 24 hours. The septic tank design should account for the sludge holding period. This, on the other hand, increases the cost of maintenance. If the design does not account for all users, the tank will block more often and require emptying more frequently. The tank should be able to hold the total waste for all users during the detention period. The amount of sewage flow highly depends on the number of users. The table below shows capacity Viz a Vis number of users. Depending on the type of house and the number of the user, septic capacity can be customized. In addition, space for sludge and scum accumulation before emptying is also considered. The s eptic tank capacity depends on the sewage flow and detention period. Factors to Consider When Designing a Septic Tank Septic Tank Capacity/Size Some tanks may include a pump to assist in pushing water out of the septic system. Send the wastewater out to the drain field- the treated waste is released to the ground or left to percolate into the soil.

#Septic tank and drain field layout free#

The bacteria feed on solid waste and free it from pathogens. Decomposes the solids– Bacteria is used to decompose the solid waste into liquid.The solids materials remain for degrading. The wall separating the chambers allows for liquid only to move to the second chamber. Separates the solids from the liquids- The solid waste settles at the bottom of the tank.Receives the wastewater from the house- all the house wastewater goes to the septic tank through one inlet.How a Septic Tank WorksĪ septic tank works in four basic steps. In addition, it should last for decades with no problems. As a result, the drainage pipes fill more evenly and preventing premature clogging of the drains, therefore, extending their life. A wall with openings between the floor and roof of the tank separates the chambers. Some septic tank design has 2 chambers while others have 3 chambers. It has one end connected to an inlet from the toilets and sometimes an outlet connected to the drain field. The floor has a slight slope of 10 percent towards the sludge outlet. The floor and side walls are made using concrete and plastered to render a smooth surface. The two compartments interconnect above the sludge storage using pipes or square openings.Ī concrete or plastic tank is the best to use. It, therefore, perform better than the single compartment tank.

The wall separating the two is about two-thirds the length away from the inlet. Larger capacities are the best fit for a two-compartment tank. It is best to construct a single compartment for small capacity septic tanks.

The liquid that leaves the septic tank is then filtered at the drainfield where germs and viruses are filtered by the soil until they are destroyed.Septic Tank Design Septic Tank Design 2-3 Chambers This is done after the heavier materials sit on the bottom of the tank (forming a sludge layer) and the lighter greases float at the top of the tank (forming a scum layer). The main function of the septic tank is to retain the solids inside and release the liquids to the drain field. The wastewater is delivered to the soil where the germs and chemicals are removed before they reach any other adjacent water. Buried outside the home, the septic tank is connected to a buried pipe that moves the wastewater to the drainfield for further treatment. The septic tank is normally made out of concrete and holds about 1,000 gallons, but the number of bedrooms in the house is what legally determines its capacity. The main function of the septic tank is to treat the household wastewaters and get rid of disease-causing germs and pollutants.Ī septic system design will have a septic tank, a drainfield, and the soil under the drainfield. Septic tanks are mostly designed for rural and suburban homes where sewage treatment plants are not available. The main function of a septic tank is to collect, treat and dispose of sewage produced in the bathroom, kitchen and laundry rooms.