Residential
Version :
GSF
System :
Modulor
Lifespan :
+ 20 years
Application :
Residential
ELJEN
A passive and effective solution
ELJEN GSF is used in hundreds of thousands of on-site wastewater treatment systems across North America. It is one of the only technologies tested in winter conditions that has demonstrated outstanding performance even in cold weather. Its compatibility with Canada's harsh climate and its unique features simplicity, no mechanical components, no need for electricity, and high-quality treated wastewater make it a wise choice.
Considered one of the best technologies available, it stands out for several reasons:
- 100% passive (no pump, no aerator, no alarm, no electricity required)
- High performance enabling reduction in required floor space
- Longer service life
- Proven process for over 45 years
- Modular and capable of treating a wide range of wastewater flows
- Suitable for all types of terrain
- No maintenance (if required by your regulations, an inspection with or without sampling may be required)
ELJEN GSF: a sustainable and economical solution
With a lifespan that can easily exceed 20 years, the ELJEN GSF will undoubtedly be your last septic system ever and by far the most economical solution among the advanced treatment systems on the market.
A solution suited to a wide variety of projects
Whether for your primary or secondary residence, ELJEN GSF is definitely the solution for you.
Distribution and service in Canada
Eljen GSF modules are distributed by Enviro-STEP Technologies for residential and commercial projects in Ontario, Manitoba, and the Maritimes.
How it works
Optimized two-stage biofiltration treatment
Step 1
The first stage of treatment takes place inside the patented ELJEN GSF modules. Each module consists of a geotextile biofilter configured with alternating effluent feed channels and geotextile barriers where active biomass develops to filter and purify wastewater. The succession of feed and biofiltration cycles ensures the constant renewal of oxygen necessary to maintain optimal aerobic treatment.
The geotextile surface area provided in each module is very high, ensuring that pollutants are almost completely degraded and that minimal residue accumulates in the system. This gives ELJEN a very long service life.
Step 2
The second stage of the ELJEN GSF treatment takes place in a thin layer of filter sand at least 150 mm thick located under and on the sides of the modules. The effluent from the modules disperses laterally and vertically in the filter sand to quickly remove water from the modules and provide additional filtration treatment. The treated water then travels across the entire surface of the application area and percolates into the soil. The sand layer ensures that the treated effluent is dispersed and prevents localized hydraulic overload of the soil. This limits compaction and preserves the natural permeability of the soil throughout its lifetime. This maximizes the service life and reduces the risk of clogging.
Performance
Consistent, high-performance treatment, even in cold climates
Twelve-month trials, including 12 consecutive weeks at water temperatures below 10°C,
demonstrate that the system maintains stable effluent quality that complies with advanced treatment standards.
Unlike many cold-sensitive technologies,
ELJEN GSF retains its biological and hydraulic effectiveness throughout the year.
ELJEN GSF
12-month performance
(including 12 consecutive weeks at a temperature below 10°C)
DBO₅C (mg/L)
Suspended solids
(mg/L)
Fecal coliforms (CFU/100ml)
Average
2.0
2.7
66*
Average (water < 10°C)
1.2
1.7
13*
Median
1.0
2.5
71*
Minimum value
1.0
2.5
2*
Maximum value
7.2
7.0
10 965*
* Geometric mean
Specifications
ELJEN GSF passive biofiltration modules are integrated into the wastewater dispersion field and combine two treatment stages to produce very high-quality effluent that meets the most stringent standards.
Pollutants are reduced through biofiltration treatment in the ELJEN GSF modules and then in a thin layer of filter sand located on the sides and underneath the ELJEN modules. The treated water is then discharged either through infiltration into the natural soil directly surrounding the modules.
Your questions, our answers
What is an ELJEN GSF system?
The ELJEN GSF is a wastewater treatment system for properties without access to a municipal sewer system. It uses a combination of biofiltration and filter sand to purify water naturally, without complex mechanical parts.
Why choose ELJEN?
Because it is simple, durable, and economical. It protects the soil, requires little maintenance, operates without electricity, and provides higher-quality effluent than traditional fields, reducing the risk of future problems.
Does ELJEN replace a septic tank?
No. It works in conjunction with the septic tank. The tank pre-treats the wastewater, and the Eljen GSF performs advanced filtration, improving the quality of the effluent before it infiltrates into the soil.
What's the lifespan of the system?
The structure of the system can last more than 20 years. Only the modules need to be replaced at the end of their service life, which avoids having to completely rebuild the treatment field and reduces long-term costs.
Does ELJEN work well in winter?
Yes. The ELJEN system has been tested in cold conditions and maintains excellent performance even when the water temperature drops below 10°C. Since it does not use any mechanical or electrical parts that are sensitive to freezing, it remains reliable all year round and does not require any special winter protection.