Frequently Asked Questions

Your discharge filter needs to be cleaned every couple of months, to protect your pump from overheating. You may elect to clean your BioCycle discharge filter yourself, or ask your Service Agent to do this for you on a schedule. Your Service Agent will clean it during routine maintenance schedules of six months as well.

Simply unscrew the grey-black housing (see photo) and remove the red disc filter cartridge. Release tension on discs by unscrewing the cartridge a few turns (there is no need to disassemble the cartridge entirely), then hose off with clean water (preferably over a mulched garden bed, or in a large bucket which can be emptied into a gully trap) until discs are totally clean.

Screw back together only up to a soft 'bite' between discs... DO NOT OVERTIGHTEN, as this will restrict water flow through the filter. Replace cartridge into housing and screw on cap until nipped tight, using hands only, no tools.

You can download and print an instruction sheet on our Technical Documents page.

We stipulate a routine service should be carried out every six months. After 30-years experience in the on-site wastewater treatment industry, our staff know that 6-months is a safe average interval between routine service inspections. 

Yes, we realise that some competitors claim "12-monthly" and sell this as "costing less", but this claim is often retracted when the sale is complete and your system isn't functioning well after only eight months or so in the ground. Perhaps a Service Agent advises that the filters are blocked so you need to reduce your interval to 6-monthly due to your home's 'special' or 'unusually high flow rate'. 

While an AWTS operating well might last 12 months or more without a blocked filter, manufacturers in the industry with a sound moral compass will stipulate 6-monthly services, based on experience and providing peace of mind for you as the home owner.

Neglecting your AWTS can be costly, just as neglecting to service your car can be.

Yes. ALL types of septic tanks and AWTS systems need to have the sludge removed by a 'sucker-truck' occasionally. 

As part of the bacterial digestion process, sludge builds up in the bottom of the tank, usually in the Primary or Septic chamber only, and when this reaches a critical level (your Service Agent will advise when), your system will not function correctly, due to insufficient space within the chamber.

Every home and system is different, but pumping out the tank is usually required about every 5-10 years for a Septic Tank, or 3-7 years for a AWTS tank, depending on design and occupancy level of the home.

Generally speaking, the process works like this:

1. Concept decision on building design with building company, along with property layout preference. Bedroom numbers are a critical decision and anything which may be construed as a bedroom, such as an office or rumpus room needs to be clear so that total occupancy, flow rates and wastewater system size can be determined.

2. Engage Geotechnical Engineering consultant for site and soil stability report. This report provides critical information relating to your particular site, such as whether it is in a flood plain, and what the soil composition is, so the wastewater discharge design can be tailored to your property.  

3. Contact and selection of earthworks and drainage contractor. Discuss site and soil report and whether Geotech Engineer will include Wastewater Design Report, or the Drainlaying Contractor will undertake this for you? Engineers usually charge between $1000 and $3000 for the Wastewater Report, while a Registered Drainlayer endorsed as a Wastewater Design Author (Suitably Qualified Person - SQP), will typically charge around $500-$1000. It helps to choose Wastewater Treatment System brand at this time, so the Design Report is specific to the brand of system, as generally required by Council.

4. Finalise Building Plans and choose Wastewater Treatment System brand - usually discussed with Drainlayer and agreed at time of contractor quotation acceptance. Choose Water Supply Tank type and pump-filter configuration (if required for site). 

5. Building Consent application to Council. Wait patiently.

6. Some sites need the Wastewater Treatment System and Water Tanks installed before the dwelling is built. Failure to get this right can cause major access hassles and additional costs later.

7. Dwelling is built and tanks connected to house by Plumber - Note: 'Fall' of drains from house needs to match the tank installation height. This needs to be discussed with your chosen Builder and Plumber at sub-floor planning stage. It can be a costly disaster if the Plumber gets this wrong, but you accept the building plans. Tanks should not be buried deeper than designed and doing so may void warranty.

8. Your chosen electrician supplies power to the wastewater system and water pumps.

9. Irrigation field installed and system commissioned, ready for use. Maintenance Agreement signed and copy provided for Council, along with 'As Built' or 'As Laid' diagram and Completion Certificate. Producer Statements issued by designer.

10. Final Council Building Inspection.

This is a common and important question relating to all SAF (Submerged Aeration Filter) type treatment systems. It often stems from some competitors in our industry who sell alternative technology types (such as Textile/PBR or Vermiculture), which may not require mechanical blowers running on electricity. Of course, once the seed of fear is planted in your mind, it becomes an objection to anything which uses power and pumps whether true or not.

The truth is, most systems have been independently tested and results have proven that when it comes to electricity consumption, there is little to argue about nor compete over. For example, a well known brand manufactured in Northland which utilises Textile filter technology has been proven to use approximately 0.9kWhr/day in an average 4 bedroom home. The BioCycle and similar SAF type systems use around 1.5kWhr/day.

If a kWhr costs around 25cents, and the difference in consumption is 0.6kWhr/day, then the difference in operating costs is around $4.50/month, or approximately $55 per year.

View cost graph here

So when Textile type systems cost considerably more to manufacture and maintain over the long term, where's the advantage? There isn't any. In fact, the Textile type system will take more than 18 years to pay you back for the higher purchase price, so why pay more for something you don't need?

SAF technology has been proven over the past three decades to be the most reliable and stable technology throughout the seasons. That's why most reputable manufacturers utilise SAF technology in their systems, while others come and go in a few short years, leaving their customers without after-sale support.  

It's possible you can...depending on your local Council planning rules. Some areas have special rules due to sensitive water bodies. Please contact us and we'll help determine the best solution for your specific site. 

As New Zealanders we generally all share a passion for enjoying the Great Outdoors and caring for our natural environment. As we all work towards better standards for environmental pollution from the Agriculture and Horticulture sectors, so too are central and local Government officials working hard on improving the standards of domestic and commercial Wastewater Management, at both municipal and rural treatment facilities.

So part of each individual household's responsibility is to ensure the wastewater we generate is managed well and returned to our soil and waterways in the safest 'treated' format possible. The reality is, extensive pollution we have allowed to occur historically through leaching of low quality effluent into New Zealand's rivers and estuaries is causing the collapse of these delicate ecological environments (let alone our swimming beaches) and we need to move forward together with solutions which only cost a small percentage more than the old Septic Tanks. 

The alternative to an "on-site AWTS" for beach or rural communities, is pumped communal pressure sewer treatment plants, costing many millions of dollars in both set up and annual maintenance. So if a scheme like that goes ahead, you should expect to see a significant increase in your annual Rates to pay for it.

It is important to understand that every property has its own characteristics and each Regional Council has varying rules. So each property needs to be assessed for access, topography, building layout and size (bedroom numbers are used to calculate occupancy and daily discharge), future proofing and distance from resources such as aggregate quarries etc. So it is very difficult to quantify pricing off the shelf.

For the purpose of answering this common question, to install a BioCycle system for the average 4-bedroom home with easy access, the investment will generally range between $12,000 and $18,000. 

Your local BioCycle installation agent will be happy to visit your site and meet with you to discuss your property and plans. As part of this visit your agent can also offer a package solution which may include water storage tanks, pumps and filtration, plumbing and or earthworks. Rather than getting multiple tradies to cart machinery and personnel to your site, having one contractor to manage all facets could save you $thousands on extra transport and logistics charges.

We understand completely! Please just call and talk it over with Mike, our General Manager.

Mike's a good kiwi bloke and he has many contacts throughout the industry. We promise you he will help with integrity and honesty, using basic language to discuss the best options available for your personal circumstances. 

It's becoming common throughout the building industry for allegiances to be made and for specifying engineers and architects to favour a particular brand...sometimes without any good technical reason.

Ultimately, an appropriately designed system with great after-sale support, which complies with regulations AND meets the customer's budget, should be specified.

We're happy to help you with this process if your engineer or architect is being difficult. Please just ask.

While we do offer alternative light weight Taylex tanks for special applications, we prefer concrete due to four main reasons;

1. Pre-cast concrete tanks are durable and robust, lasting many decades without degradation or failure. Your BioCycle tank is guaranteed for 10-years from installation, although we anticipate it will long outlast you at your property.

2. Concrete is a great insulator, maintaining a very stable temperature environment inside your BioCycle treatment system. Remembering that your Wastewater Treatment System is ultimately a living organism, the more stable the internal environment the better bacteria will thrive, processing your waste more efficiently and quickly, reducing any odours. Note that our Taylex tanks are three layers of plastic, providing similar insulation to concrete, while other brands of plastic AWTS are single skin plastic offering virtually no insulation at all.

3. Our concrete tanks weigh 8-tonne (empty) and never pop up during a flood event. Likewise, earthquakes and seismic shift won't damage our concrete tanks, but the same can't be said for fibreglass or plastic alternatives.

4. A concrete tank is generally significantly less expensive to produce than rotationally moulded plastic tanks.