North Texas Septic
Aerobic Septic Systems
Aerobic systems are similar to conventional septic systems in that they both use natural processes to treat wastewater. But unlike septic anaerobic treatment, the aerobic treatment process requires oxygen. Aerobic treatment units, therefore, use a mechanism to inject and circulate air inside the treatment tank. This mechanism requires electricity to operate.
For this reason, aerobic systems cost more to operate and need more routine maintenance than most septic systems. However, when properly operated and maintained, aerobic systems can provide a high quality wastewater treatment alternative to septic systems.
Aerobic systems treat wastewater using natural processes that require oxygen. Bacteria that thrive in oxygen-rich environments work to break down and digest the wastewater inside the aerobic treatment unit.
Like most onsite systems, aerobic systems treat the wastewater in stages. Sometimes the wastewater receives pretreatment before it enters the aerobic unit, and the treated wastewater leaving the unit requires additional treatment or disinfection before being returned to the environment.
Such a variety of designs exists for home aerobic units and systems that it is impossible to describe a typical system. Instead, it is more practical to discuss how some common design features of aerobic systems work and the different stages of aerobic treatment.
Some aerobic systems include a pretreatment step to reduce the amount of solids in the wastewater going into the aerobic unit. Solids include greases, oils, toilet paper, and other materials that are put down the drain or flushed into the system. Too much solid material can clog the unit and prevent effective treatment.
Some pretreatment methods include a septic tank, a primary settling compartment in the pretreatment unit, or a trash trap. Pretreatment is optional but can greatly improve a unit's performance.
Aerobic Treatment Units
The main function of the aerobic treatment unit is to collect and treat household wastewater, which includes all water from toilets, bathtubs, showers, sinks, and laundry. Aerobic units themselves come in many sizes and shapes-rectangular, conical, and some shapes that defy classification. There are two typical aerobic treatment designs: (1) suspended growth units and (2) attached growth units.
The process most aerobic units use to treat wastewater is referred to as suspended growth. These units include a main compartment called an aeration chamber in which air is mixed with the wastewater. Since most home aerobic units are buried underground like septic tanks, the air must be forced into the aeration chamber by an air blower or through liquid agitation.
The forced air mixes with wastewater in the aeration chamber, and the oxygen supports the growth of aerobic bacterial that digests the solids in the wastewater. This mixture of wastewater and oxygen is called the mixed liquor.
Unfortunately, the bacterial cannot digest all of the solids in the mixed liquor, and these solids eventually settle out as sludge. Many aerobic units include a secondary chamber called a settling chamber or clarifier where excess solids can settle. Other designs allow the sludge to accumulate at the bottom of the tank.
In aerobic units designed with a separate settling compartment, the sludge returns to the aeration chamber. The sludge contains bacterial that also aid in the treatment process. Although, in theory, the aerobic treatment process should eventually be able to consume the sludge completely, in practice, the sludge does build up in most units and will need to be pumped out periodically so that solids don't clog the unit.
Once the wastewater has passed through the aerobic unit, it will be disinfected with some type of disinfection, most commonly chlorine tablets. However, there are alternatives to the chlorine tablets, ultraviolet light and liquid bleach chlorinators. Please visit the chlorine tablets/ alternatives section to see the liquid chlorinator and UV disinfection devices we carry and install.
The water is then stored in a “pump” tank until a predetermined amount is collected and then its dispersed. The treated wastewater may be dispersed in a few ways. One is surface application, sprinklers, and sub-surface drip, using drip emitters. The pump tank also serves as a storage tank in the event that your water pump malfunctions. This tank is where the HWA, high water alarm, is located and will activate your alarm in the event of a high water situation. The area around your sprinklers or subsurface drip area should not be allowed to collect water. This collection of water that was not from the septic system will cause an impairment of the dispersal area.
We at NTS have the ability to outfit your septic system with an “auto dialer.” This auto dialer will do what it sounds like. In the event of an alarm situation the control box will automatically call NTS and advise the staff of an alarm situation and a service call can be scheduled much faster. This type of notification requires a special alarm box and a phone line be supplied to the box. The normal house line is sufficient.
Which system should I install? Standard or Aerobic Septic System?
Our experienced and trained staff at North Texas Septic can help you choose which type of septic system is best for your property. One of our technicians will come out and give you a custom quote and answer any questions you may have regarding septic tank systems and where it should be located on your property.
Internal illustration of an Aerbic Septic Tank