Frequently asked questions


Where can I find information on onsite sewerage treatment systems?

Information about on-site sewerage treatment facilities is available at the Queensland Government website. We also have a Looking After Your HSTP – Orange Info Sheet that outlines basic information for those new to non-sewered properties.

How do I look after my HSTP?

The greatest causes of problems with your treatment plant are cleaning products and the washing machine. Do I have to use any special type of detergents and washing powders? PLEASE NOTE: The following information is not intended to promote or discredit the product of any Company. It is provided to assist in ensuring the satisfactory on-going operation of your system. To protect the environment and ensure the longevity and optimal performance of your home sewerage treatment plant (HSTP) we recommend that you use environment friendly detergents and cleaners. Using cleaners and detergents that contain high levels of ammonia (eg bleach) and/or phosphorus is hazardous to the biological health of your HSTP. These types of cleaners kill off the natural bacteria and micro-organisms used to treat the primary effluent. Reduction of the natural bacteria of your HSTP will result in a much lower level of primary treatment and may produce unpleasant “septic” odours. High levels of nitrogen and phosphorus also contribute to the growth of algae and other less desirable micro-organisms in the environment eg algal growth in waterways. Environment friendly cleaners are those cleaners that either use no chemicals or reduced levels of chemicals. Washing powders/liquids may use labelling that indicates the phosphorus level of the product. Look for the following symbols on the packaging of cleaning products: This symbol lets you know that the product complies with the agreed Australian industry standard on phosphorus, which imposes a maximum content of 7.8 grams per wash. The standard is designed to reduce the amount of phosphorus entering Australian waterways. This symbol lets you know that the product contains no added phosphorus. Levels of 0.5% may be present. SUITABLE PRODUCTS – All products should be used in moderation DISWASHING LIQUIDS Adds Morning Fresh Bushlands Rix Palmolive Sunlight Greenapple Kit Finish for Dishwashers (limit quantity) SURFACE CLEANERS Jiff Cream Cleaner Spray & Wipe (limit quantity) Nifty Swipe Shower Power Windex TOILET CLEANERS Jiff Cream Cleaner or any cream cleaner – Toilet fresheners are not recommended. FLOOR CLEANERS Use hot water and detergent LAUNDRY POWDERS AND LIQUIDS We highly recommend visiting this independent website for further information on laundry products. They have a concise, comprehensive and independent brochure detailing laundry products that is available for free download. AVOIDABLE PRODUCTS ANTIBACTERIAL SOLUTIONS Antibiotics Nappy Plus Pineoclean Blue Loo Napisan Preen Soaker Bio-Ad Nappy Soft Tri-zyme Bio Jo Nappy Fresh Toilet Duck Milton Tablets Nursil Toilet Cleaners BLEACHES Domestos Lemon Bleach White King Budget Lemon Zixo Fiesta Marvolinn OTHER CLEANERS Ajax ESP Herbal Metho or Kero Swipol Aussa Exit Mould Flea, Tick Wash Handy Andy Bubble Baths Floor Cleaners Spirits/Alcohol Draino Caustic Oven Cleaners Green Choice Down to Earth TOILET PAPER The basic problem is that ALL toilet paper is biodegradable and generally advertises this point prominently on their packaging…so consumers are not aware that their choice in this area may affect the operation of their plant. While all toilet paper biodegrades the rate at which this occurs differs vastly between products and this is where the problem comes in with your treatment plant. We advise consumers to choose toilet paper that biodegrades quickly and easily – but how to work out which ones do and which ones don’t? After a bit of googling the only article we could find to assist consumers in this area was a star rating page given to various brands of toilet paper by Choice. The star rating is not directly linked to biodegradability rates but is based on the “greener” choice. Basically products that use higher recycled or farmed tissue and less bleaching are rated higher than those that do not. The higher the recycled content and the lower the bleaching may also indicate a faster rate of biodegradability. Apart from this guide the only other advice we can offer is by trial and error. We are happy to have feedback on this area if someone has a product they want to recommend. QUICK TIPS – Do’s & Don’ts DO Try to evenly spread your washing over a period of a week. Avoid where possible to wash everything in one day. It puts to much water in the system and your HSTP will struggle to cope. Liquid soaps breakdown easier than granulate styles do. Try not to be heavy handed with the amount of soaps you use. Use only recommended biodegradable products that don’t contain disinfectants. Any product used that kills bacteria is harmful to your system. If you wish to use some of the harsher cleaning products, it is suggested that you use a bucket and discard the contents in the garden. This also applies to disinfectant, surface sprays and wipes. The use of toilet paper that disintegrates easily is recommended. With a new installation or immediately after a pump out, it is essential that the tank be filled with water. The build up of sludge in the bottom of the primary/secondary sectors of the treatment system must be removed regularly (approx every 5-10 years). Maintain mosquito proofing on all vents. Mosquitoes can breed rapidly in the environment of a sewerage tank. Ensure that your disposal area is operating as designed – wastewater should be disposed of evenly over the entire irrigation area. Avoid ponding. Move sprinkler hoses regularly (ensure hoses are not kinked and sprinklers are not blocked). Maintain signage. DON’T: Do not allow foreign objects, (eg. Nappy liners, disposable nappies, tampons, pads, condoms etc) to enter the system. Pouring large quantities (1/2 litre or more) of beer, wine, milk or fruit juice into the system should be avoided as it can upset the balance in your system. Do not use garbage grinders or insinkerators. Do not cover tanks with earth, cement, paver or any material. Do not prevent quick and easy access to any inspection openings. Do not allow roof or surface water to enter any part of the system. Ensure that diversion mounds around the media filter bed are maintained. Direct surface water away from media bed and treatment tank and ensure that stormwater/rainwater outlets do not discharge in the treatment area. THINGS TO ABSOLUTELY AVOID: Chlorine, disinfectant, bleaches, caustics and heavy chemical products, nappy san, antibacterial products, fat, oil, grease, milk, etc are some of the types of products that will cause the bacteria to die off in your HSTP. We do recommend that you regularly review the “Ten Commandments for Septic Tanks”(applicable for both all waste septic systems and wastewater treatment plants) to ensure that everyday practices comply with the general “Do’s & Don’ts”. WATER USAGE Water usage is a factor that also needs to be considered. When wastewater treatment systems are installed they are designed to treat an expected hydraulic load subject to the number of bedrooms in the house (and therefore expected maximum occupancy). This occupancy rate, along with standard water usage per person rates provided through the State Standards allows the designer/installer to calculate system size and disposal area required. High water consumption (above the designed hydraulic load) will place a heavy load on the wastewater treatment system and disposal area and affect treatment effectiveness and efficiency. A good starting point for checking your water usage is to look at your rates notice. This notice will generally state the average consumption for your property, your local area and the council area. As a guide the average usage on the Fraser Coast is approx 540L/day (source: Wide Bay Water Rates Notice – 2nd rating period 1/07/11-29/02/12). To estimate your water usage: Note the reading on your water meter on day 1 and then again on day 7. Calculate the difference. Divide by 7. This is a ROUGH estimate of your water usage per day. Remember to pick a standard week – ie when all occupants are present and normal activities are undertaken as this will help you to get a more accurate estimate.

Do I need to do any special landscaping?

Generally no. However it is advisable to ensure that stormwater run-off is diverted away from the sand media filter, sewerage tank and disposal field. This is to limit the entry of excess water which does not require treatment and to prevent saturation of disposal field hence increasing the lifetime of your Household Sewerage Treatment Plant (HSTP). Since HSTP’s are commonly installed at an early stage of construction it is sometimes difficult to provide advice with regard to landscaping requirements. Owners who are concerned with possible stormwater run-off should talk to their sewerage site evaluator or HSTP installer and advise them of their concerns – discussion of diversion options can then take place. As a general rule, if it becomes apparent that stormwater run-off flows in the direction of the sand media filter, sewerage tank and disposal field some landscaping will be required to divert this flow. This may be in the form of a diversion mound – a raised mound of grass/mulch covered soil to divert water flow away from the HSTP. Alternatively diversion mounds may be designed in the form of garden beds .

Why do I need to have my septic/treatment tank pumped out?

Desludging of primary tank will be required every 5-7 years (and in smaller capacity systems more often). It is important that the treatment tank is immediately filled with water on completion of pump out to appropriate level to ensure tank does not “pop” out of the ground. Take care with internal baffles and avoid contamination between chambers. We recommend downloading our information sheet that outlines the basic operation of septic/treatment tanks, why they need pumping out, what is involved and how much it costs. We provide a complete de-sludging/pump-out service – please contact Brett on 07 4128 8019 for further information or download our Pink Info Sheet.

Does CWWS undertake general plumbing work?

We specialise in onsite wastewater treatment and we do not usually undertake general plumbing work unless it is directly associated with wastewater treatment. Our scope of works start at the treatment tank and extends out to the disposal field.

I am buying a property with an onsite wastewater system and I would like someone to inspect it to advise on its type and condition. Does Coastal Wastewater Specialists offer this service?

Yes – we do offer a pre-purchase inspection service. Further details on this service are available here.