Living Machine^® Systems

Treating Wastewater Nature’s Way

Frequently Asked Questions

What is a Living Machine^® system?

A Living Machine system is a patented approach to ecological wastewater treatment that enhances the effectiveness of the same biological processes that occur in a natural wetland. WWT and its predecessor companies have developed and applied several generations of technology under the name “Living Machine”. The current generations of the Tidal Flow Wetland Living Machine and the Hybrid Wetland Living Machine are significant advances over the previous generations and our Living Machine systems are the only technologies currently authorized for sale under the trademarked name.

Why is a Living Machine system better than a conventional constructed wetland?

Living Machine systems achieve measurably better treatment in a smaller area than conventional wetlands by employing advanced hydraulic designs coupled with mechanical and electronic control systems. The Living Machine patented technology enhances the natural biochemical and physical processes of wetlands to:

1. Accelerate treatment
2. Achieve predictable performance
3. Reduce emissions of greenhouse gases

How does a Living Machine system compare to other onsite wastewater treatment systems?

Living Machine systems have most of the advantages of natural treatment systems while providing the performance, control and monitoring benefits of mechanized systems. As our Systems Profile Comparison indicates, Living Machine systems have a significantly smaller footprint than conventional constructed wetlands and significantly lower energy consumption than highly mechanical systems. The treatment performance of Living Machine systems equals or exceeds those systems. Living Machine systems offer significant benefits for installations desiring onsite reuse, low operations cost and integration with the landscaping.

What are the components of an onsite wastewater treatment system?

Principal components of an onsite wastewater treatment system include:

Collection system — The collection infrastructure intercepts wastewater flow from buildings or other sources and transports it to a primary treatment system.

Primary treatment — The first step in all onsite systems is some form of primary treatment wherein large solids and most settling and floatable wastes are removed. Primary treatment is most commonly accomplished in a septic tank but fine screening is also used. Wastewater is then typically pumped from the primary treatment to the secondary treatment system.

Secondary treatment — Secondary treatment processes remove suspended solids (measured as total suspended solids or TSS) and dissolved organic constituents (measured as biological oxygen demand or BOD). Advanced treatment systems remove BOD and TSS to very low levels and usually remove nutrients such as nitrogen or phosphorus. Living Machine systems achieve advanced secondary treatment and are easily coupled with disinfection and water reuse functions.

Disinfection — After secondary treatment, chemical or physical based disinfection technologies may be employed to remove pathogens.

Reuse or disposal — This is the final stage wherein treated effluent is returned to the environment through discharge to ground or surface waters, or reused for an approved purpose.

What is the reuse potential of effluent from a Living Machine system?

Treated effluent from a Living Machine system can be used for a variety of non-potable applications. Frequently, a disinfection system is also required to achieve effluent reuse standards. Effluent from Living Machine systems has been reused for subsurface irrigation, toilet flushing, kennel washing, zoo exhibits and other uses. Living Machine systems’ effluent has also been discharged directly back to the environment in surface or ground water. In addition, treated effluent from wetland treatment systems has been shown to increase the growth rate of some non-food crops (e.g., hay, bamboo, flowers, etc.).

Is a Living Machine system safe? Are there any odors associated with the process or the effluent?

Wastewater is always below the surface of the Living Machine system’s wetland media (crushed aggregate) so there is no potential for accidental contact with partially treated effluent or a mosquito breeding habitat. The wastewater odors are eliminated by a careful design relying on simple odor removal mechanisms. A properly maintained Living Machine system will have the pleasant smell of the plants used in the wetland, including flowers where flowering plants are chosen. Many of our systems have been built inside buildings with no distasteful odors.

What are the effluent standards for a Living Machine system?

Living Machine systems can achieve advanced tertiary treatment by meeting the following effluent values:


Pathogen removal requires the use of a disinfection system after treatment.

What kind of wastewater can a Living Machine system treat?

Our technologies can treat wastewater from most domestic, municipal and commercial sources. Living Machine systems have been designed for municipal wastewater, animal wastewater, food production wastewater, brewery wastewater, food processing wastewater, domestic greywater, and stormwater.

Does a Living Machine system need to be in a greenhouse enclosure?

In climates with cold winters, a greenhouse enclosure may be required for the Tidal Flow Wetland Living Machine system and for a portion (~1/3 area) of the Hybrid Wetland Living Machine system. Based on local climate data, Worrell Water Technologies engineers can determine whether an enclosure will be required for a particular site.

What is the treatment capacity for Living Machine systems?

Living Machine systems in operation range from 2,500 gpd (approximately 6 single‑family homes) to 200,000 gpd (approximately 500 single‑family homes). The Living Machine technological is easily scalable and larger systems are more cost effective, benefiting from economies of scale.

Does a Living Machine system save water?

The high quality effluent from Living Machine technology facilitates reuse and maintains ground and surface water resources, thus helping to conserve water. Reuse greatly reduces the demand for local fresh water supplies and high quality discharge helps protect their quality. Reuse systems coupled with Living Machine systems currently save millions of gallons of potable water each year.

Does a Living Machine system save energy?

Our Tidal Flow Wetland and Hybrid Wetland Living Machine systems use less than 1/3 of the energy of a comparably sized activated sludge system (the most common conventional system) and produce higher quality effluent. The combination of the energy savings and the virtual elimination of methane emissions from the wetland beds allows the Living Machine system to offer greatly reduced greenhouse gas impact compared to aerated wastewater treatment processes or conventional wetland systems.

If I install a Living Machine system, will I have to deal with residuals requiring disposal?

All onsite wastewater treatment systems utilize primary treatment that generates residuals, which require disposal. In secondary treatment, however, the advantage of using a Living Machine system is there is no waste bacterial mass or sludge produced in this stage, unlike some other methods.

What residuals management is required with a Living Machine system?

Like any other onsite treatment system, your primary settling (septic) tanks must be pumped periodically (every 2‑5 years) and the septage taken to an approved management facility. For larger systems, primary screening is substituted for a septic tank and results in very low volumes of primary residuals that are dry and easily managed. These compacted solids are typically sent to a landfill but may be used in a waste‑to‑energy facility.

Also, all constructed wetlands used in wastewater treatment will require periodic maintenance of the vegetation.

What is the size of a Living Machine system?

As our System Profile Comparison indicates, the Tidal Wetland Living Machine system requires approximately 150 ft² for every 1,000 gallons treated (e.g., 7,500 ft² for 50,000 gpd). The Hybrid Wetland Living Machine system requires approximately 500 ft² for every 1,000 gallons treated (e.g., 25,000 ft² for 50,000 gpd). Typical subsurface flow wetlands require approximately 750 ft² for every 1,000 gallons treated (e.g., 37,500 ft² for 50,000 gpd).

Can I get a wastewater discharge permit with a Living Machine system?

Worrell Water Technologies will work with your team to obtain required permits. To date, all permit applications have been approved. However, Living Machine systems generally cannot be built in areas that do not allow onsite treatment systems.

Does a Living Machine system require special training to operate?

Skills needed to run our systems are very similar to those of other onsite systems and can be quickly learned by contract operators or other appropriate personnel. Worrell Water Technologies provides onsite training and support for operation of our systems to designated staff or contract operators. Vegetation maintenance is generally performed on a seasonal or annual basis and can be performed by landscape contractors or by site staff.

What clients have used Living Machine systems?

A number of commercial, institutional, and government clients have used Living Machine systems including M&M Mars, The El Monte Sagrado Resort, Smuggler’s Notch Resort, The Audubon Society, Oberlin College, The State of Vermont, the Animal Foundation of Las Vegas, NV, the City of Dallas, TX, the Esalen Institute and many others. Our systems have been in operation for over a decade.

Can a Living Machine system be harmed by chemicals?

The complex ecology of the Living Machine system makes it more resistant to bio‑toxic chemicals than suspended growth bacterial systems such as activated sludge package plants and very ecologically simple systems. However, every effort should be made to prevent the release of toxic chemicals to protect the functioning of the treatment system as well as downstream ecosystems.

What is the cost of a Living Machine system?

The cost of a Living Machine system varies for each project, depending upon site‑specific criteria. The staff at Worrell Water Technologies will be happy to consult with you regarding your specific needs to help determine the costs of a Living Machine system for your site. You will find our treatment systems are very cost‑competitive with other technologies that provide onsite treatment to reuse standards.