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 Glendon® BioFilter Facts You Should Know

The Glendon® BioFilter System is the most effective on site system available on the market today. Its patented process transforms household sewage into clear, useful water which may be safely percolated into the soil or recycled in accordance with local regulations. BioFilter effluent has been laboratory tested under a variety of operating conditions and meets the specifications for Washington State Treatment Standard Number One, without disinfections. The BioFilter uses no chemicals or disinfectants, ozone, or ultraviolet processes. All of these processes or techniques are recognized as being expensive or maintenance intensive, and some can be harmful to the environment. The Model M3 BioFilter has been approved as a propriety alternative system by the Washington State Department of Health (WSDOH). The next generation BioFilter, the M31 has also been approved by WSDOH.

Operating Principles

The BioFilter acts as a living organism that breathes air and consumes organic material contained in septic tank effluent while producing essentially pure water and innocuous, odorless gasses which diffuse unnoticed into the air. The harmful organic materials in septic effluent are living and non-living organic matter dissolved and suspended in the sewage water, including sewage indicating bacteria called fecal coliform. The sewage purified by the BioFilter is no longer a threat to health. It is sparkling clear, highly oxygenated, and smells fresh.


The BioFilter has the capability to produce effluent with very low levels of sewage characteristics of fecal coliform (FC), biological oxygen demand (BOD), or total suspended solids (TSS). Typical laboratory test results are:

Std. #1
Lab Tests at Site
#1 #2
FC 100ml 0.0 1.0
BOD <100ppm 4.2 2.3
TSS <100ppm 0.1 0.1


Throughout the years of service by many Glendon® installations operating in a wide variety of conditions, there have been no failures of the BioFilter. The BioFilter has no mechanical parts to wear out or get out of adjustment. It requires no power to accomplish its treatment processes. It needs no regular maintenance. It is normally fed by a small, reliable, 110 volt electric pump for metered flow.

Effluent quality is ensured by extensive anaerobic pretreatment before processing in an unsaturated, continuously purifying capillary flow through an inverted V sand path. This final process provides enhanced aerobic treatment before the purified water wicks into the surface of the native soil at the perified water wicks into the surface of the native soil at the periphery of the BioFilter where it mixes with the natural flow of local ground moisture. The treated effluent can also be collected and stored for recycling if desired. This advanced process is in a class by itself for performance, adaptability, reliability, low maintenance, and cost-effectiveness.


Glendon® guarantees the performance of each BioFilter for two years from the date of installation. The pump and timer are guaranteed for one year from the date of installation.