Residential Septic System & leach field design
BBB Septic now offers residential septic design alongside installation, maintenance,pumping, and repairs . We are proud to have a new team of professionals and a full time septic system design engineer that can assist you with testing your soil and designing the best system to fit the plot of land here in North West Arkansas. From start to finish, BBB will be with you every step of the way to assist you with your Geotechnical Engineering to make sure you have a healthy and well maintained septic system.
Designing your system
The type of septic system we can design for you depends on several factors. Primarily, the depth of soil above a restrictive layer (called a hard-pan) on your property determines the type of system that will be best suited to your needs and the available land. Septic system types in Arkansas are classified as the following.
A conventional gravity system is the simplest onsite wastewater system but requires deep usable soil depths . Typically this is going to require soil depths that exceed 30-37 Inches. A conventional gravel system is comprised of the septic tank itself and a leach field for the system.
The system is designed in such a way to allow gravity to move the wastewater throughout the septic system. It is the Goal of BBB Septic to set our customers up with a gravity fed systems as a first choice because they are comparatively lower cost and require minimum maintenance . Something else to note is that the leach field can utilize almost any type of gravel or gravel-less drainer.
The next choice would be the pressure distribution systems. These systems are typically used when soil conditions are less than optimal (having steep slopes or minimal available area). Pressure distribution systems are designed to create better distribution of wastewater over the extent of the entire leach field. Even under the less desirable property conditions.
Alternative Septic Systems
If there is less than a minimum soil depth available, then an alternative-type septic system must be used in order to protect the surrounding lakes, streams, and drinking water aquifers from the sewage runoff. There are a few types of alternative septic systems, such as:
Aerobic pre-treatment systems with pressure distribution or with drip irrigation, and bottomless sand filters
Shallow soil or the previous mentioned sloping landscape as well as other concerns such as high water tables, poor quality soil, etc will determine if one of these alternative systems are required. Typically, an aerobic pre-treatment system with pressure distribution is the least expensive option out of the 3 listed above. The are also the longest lasting alternative-type septic systems.
Aerobic pre-treatment systems, with a drip irrigation systems, and sand filters are setup to dose the leach field multiple times per day, depending on the type of system. To meet code, an alternative septic system must have a at least twelve inches of separation. The minimum overall depth of native undisturbed soil for these systems will range between eighteen and twenty four inches.
Septic Tank Construction
“A septic tank consists of one or more concrete or plastic tanks of between 4000 and 7500 liters (1,000 and 2,000 gallons); one end is connected to an inlet wastewater pipe and the other to a septic drain field. Generally these pipe connections are made with a T pipe, allowing liquid to enter and exit without disturbing any crust on the surface. Today, the design of the tank usually incorporates two chambers, each equipped with a manhole cover, and separated by a dividing wall with openings located about midway between the floor and roof of the tank.
Wastewater enters the first chamber of the tank, allowing solids to settle and scum to float. The settled solids are anaerobically digested, reducing the volume of solids. The liquid component flows through the dividing wall into the second chamber, where further settlement takes place. The excess liquid, now in a relatively clear condition, then drains from the outlet into the septic drain field, also referred to as a leach field, drain field or seepage field, depending upon locality. A percolation test is required prior to installation to ensure the porosity of the soil is adequate to serve as a drain field.
The remaining impurities are trapped and eliminated in the soil, with the excess water eliminated through percolation into the soil, through evaporation, and by uptake through the root system of plants and eventual transpiration or entering groundwater or surface water. A piping network, often laid in a stone-filled trench (see weeping tile), distributes the wastewater throughout the field with multiple drainage holes in the network. The size of the drain field is proportional to the volume of wastewater and inversely proportional to the porosity of the drainage field. The entire septic system can operate by gravity alone or, where topographic considerations require, with inclusion of a lift pump. Certain septic tank designs include siphons or other devices to increase the volume and velocity of outflow to the drainage field. These help to fill the drainage pipe more evenly and extend the drainage field life by preventing premature clogging or bioclogging.
An Imhoff tank is a two-stage septic system where the sludge is digested in a separate tank. This avoids mixing digested sludge with incoming sewage. Also, some septic tank designs have a second stage where the effluent from the anaerobic first stage is aerated before it drains into the seepage field.
A properly designed and normally operating septic system is odor-free and, besides periodic inspection and emptying of the septic tank, should last for decades with minimal maintenance.
A well designed and maintained concrete, fiberglass, or plastic tank should last about 50 years”
Source Wikipedia Septic Tanks. Retrieved from https://en.wikipedia.org/wiki/Septic_tank
- URL https://en.wikipedia.org/wiki/Septic_tank
- Website Title Wikipedia
- Article Title Septic tank
- Date Published January 23, 2019
- Date Accessed February 04, 2019
Septic Tanks & Systems Contractors BBB Has you Covered!
BBB Septic is your go to contractor in the Northwest Arkansas Area for all of your septic system needs.
4149 Cook Rd #1, Bentonville, AR 72712 – (479) 271-0058