Manual in EnglishDownload
Always ensure you are meeting local regulations. Onsite Sewage Systems – Province of British Columbia (gov.bc.ca)
We’ve laid out all the steps for installing the CITIJAL Easy-Clean Biodigester. CITIJAL’s easy-clean biodigesters are manufactured from high quality polymers formed in a single piece using a rotational molding technique so they are seamless and easy to clean. Their design also allows an easier and simpler installation, which makes them more practical for off-grid or remote locations and more affordable.
The CITIJAL biodigester also doesn’t require a pump – you can just turn a faucet to empty the waste into the secondary tank, where it dries for a few months before being a garden-ready, high phosphorus content fertilizer.
Jump to a section
How the Easy-Clean Biodigester works
Treating wastewater with a CITIJAL Easy-Clean biodigester
Choosing a location for a CITIJAL Easy-Clean Biodigester septic system
Materials for installing a CITIJAL Easy-Clean Biodigester septic system
Excavating the area and laying the foundation
Activating the anaerobic bacteria in your CITIJAL Easy-Clean Biodigester septic system
Cleaning the CITIJAL Easy-Clean Biodigester septic system
Tips for keeping your biodigester operating at peak efficiency
How the Easy-Clean Biodigester works
The anaerobic digestion process begins once the waste reaches the biodigester tank. The bacteria contained inside the biodigester break down the waste into small amounts of carbon dioxide and methane gas, as well as water and phosphorus.
The carbon dioxide and methane gas exit through the water tributary and through the vents located in the upper cover of the biodigester. The internal filter separates the water through a siphon effect or upward flow. The waste, mainly composed of phosphorus, accumulates at the bottom of the biodigester in the form of sludge. The sludge must be emptied every 12 months through the extraction valve, which is turned like a faucet to expel the sludge into the secondary tank. From there, the sludge dries for two months, after which it can be mixed with a little lime (to balance the high PH of the pure phosphorus) and added to the garden as a potent fertilizer.
Treating wastewater with a CITIJAL Easy-Clean biodigester
The internal filter of the biodigester separates the water through a siphon effect or upward flow before filtering it and draining the treated water in one of three ways: into an absorption well, through an oxidation field, or into an existing wetland.
Draining water into an absorption well
The absorption well is usually the most practical option, as it takes up less space than an oxidation field and facilitates natural drainage into the subsoil. It should be located at least 30 meters from any water well and at a distance from any building. It needs to drain into permeable subsoil, so test your soil for permeability before installing. Do not install an absorption well in clay or other ground conditions where water pools. The absorption well also can’t be too close to trees or other plants with broad root systems, as they risk clogging or breaking the system.
Create the natural filtration system by filling the excavation with a base gravel bed, a sand bed, another gravel bed and then larger stones that should make direct contact with the water outlet line. The whole well should remain below ground level.
Draining wastewater into an
oxidation field
An oxidation field is a series of perforated pipes, placed at a distance of at least 1.8 meters and with a recommended depth of between 30 to 60 cm. Again, don’t build it too close to trees, since the roots can obstruct or lift pipes. In the perforations you should place tar paper to prevent the filling material from entering the tubes, increasing humidity. The more porous the soil, the bigger the slope of the tubes should be, up to a slope of 10 percent.
Draining wastewater into a wetland
It may sound questionable, but the water that is drained from the biodigester is filtered enough to be released into a wetland without posing any threat.
Wetlands are important ecosystems and add great value to a property, as they help fortify the terrain and provide habitat to all manner of flora and fauna. A wetland is a surface that floods permanently or intermittently. It works like a sponge where water accumulates or circulates inside slowly. Wetlands are beneficial because they help regulate floods and droughts and maintain water quality by retaining sediment and nutrients removing contaminants. They act as water reserves, stabilize microclimates, and support carbon retention! If you already have a wetland on the property, you can take advantage of the natural filtration and drainage it provides.
Choosing a location for a CITIJAL Easy-Clean Biodigester septic system
Before installing a biodigester septic system, it is important to make sure you have a good location. Gravity plays an important role in drainage, so choose a location downhill for best results. You’ll need a location with good soil and a slope of at least 3 percent. Our technician will test the soil prior to installing the biodigester septic system.
Your location should also be at least 30 meters from any wells or water sources and a few meters away from any building. The absorption well also can’t be too close to trees or other plants with broad root systems, as they risk clogging or breaking the system.
Materials for installing a CITIJAL Easy-Clean Biodigester septic system
- Two 4 inch sanitary PVC pipes at least 3 meters long each.
- Two 4 inch by 90 degree elbows.
- Two 4 inch couplings
- A sludge discharge valve.
- A 2 inch tube.
- One 2 inch tube adapter.
- A tube of sanitary PVC glue.
- A sack of gravel.
- A sack of pumice rock.
- A 4 inch by 90 inch degree elbow
Excavating the area and laying the foundation
Once you have identified a location that is appropriate, you will need to excavate the area for the sanitary lines from the house to the biodigester tank and from the biodigester to the absorption well, oxidation field or wetland. Each sanitary line of four-inch PVC pipe must be a minimum of three meters long and at a 3% slope.
If you are using the absorption well method, make sure to excavate deep enough to accommodate the height of the biodigester, plus 5-15cm to compensate for the thickness of the concrete foundation where it will be placed. Excavate a space wide enough for the diameter of the biodigester, plus a 40-50cm margin.
Before placing the biodigester inside the excavation, build a concrete to protect the system from any sharp stones or anything else that could damage the structural integrity. Carefully lower the biodigester into the excavation and onto the foundation.
Once the line from the house to the biodigester is installed, dig a cavity on the side of the biodigester with the extraction valve. The cavity should be at least 40cm from the biodigester, connected to it with a two-inch adapter. The sludge container must be waterproof and have a lid that is not hermetic to facilitate the drying of the sludge.
Next, install the sanitary line for the discharge of treated water from the biodigester to the absorption well, oxidation field or wetland. This line of four-inch PVC also needs to be at least three meters long and at a three percent slope.
Considerations:
Whichever drainage option you choose, it must be located at a distance not less than 30 meters from any water well and at a distance not less than its depth from any building. The subsoil must be permeable at a shallow depth. The absorption well must be far from any tree or plant, so that it cannot be reached by the roots. If you opt for the absorption well, fill the excavation with a base gravel bed, a sand bed, another gravel bed and then larger stones that should make direct contact with the water outlet line. The whole system should be underground, preventing the installation from being visible.
Activating the anaerobic bacteria in your CITIJAL Easy-Clean Biodigester septic system
Once the biodigester, secondary sludge container and all the pipes have been installed, activate the anaerobic bacteria by filling the biodigester with water up to five centimeters below the treated water outlet connection. Level and close the biodigester before filling in the excavation and leveling the ground.
Leave the covers of both the biodigester and the sludge container visible so you can access the cap for easy cleaning and so you can assemble the internal filter of the biodigester. To create the internal filter, pour a layer of gravel into the Biodigester, followed by a layer of pumice rock and then another layer of gravel.
Cleaning the CITIJAL Easy-Clean Biodigester septic system
Every 1-2 years, clean out your Easy-Clean Biodigester using the following steps:
- Remove the cover of the sludge container.
- Open the discharge valve and empty the biodigester into the secondary tank until the emerging sludge changes to a yellowish color.
- Close the discharge valve and cover the sludge in the secondary tank, ensuring it is waterproof but not air tight.
- Leave the sludge in the secondary tank to dry for 2 months.
- Once the sludge is dry, open the secondary tank and extract the phosphorus. Wear personal protection including gloves, boots and face mask as these materials are concentrated and potent and not to be breathed in. Mix the dry materials into your compost or add a little lime and place it directly in the garden.
Tips for keeping your biodigester operating at peak efficiency
Use organic, biodegradable soaps and cleansers. Disinfect your toilet by moistening a cloth with bleach, but avoid pouring chlorine directly into the toilet. Don’t flush toxic or nonbiodegradable substances – ideally, only toilet paper and natural excretia will be entering the system.