Useful Resources

We’re happy to share our knowledge

It works better for everyone if we all know how to best care for our Septic Systems. Here we’ve collated and created some helpful guides for your system. If you’re still unsure, we’re also happy to talk you through your particular system’s operation on site - just give us a call!

Maintenance Contracts

If you would like to ensure that your septic system is always running as intended the best option would be to set up a maintenance contract with Greenacres. This keeps your system running perfectly and also satisfies the council’s maintenance requirement for Septic Systems.

Septic Tanks

Older Island homes rely on septic tanks for their sewerage treatment and disposal.  As long as these units are properly maintained and their disposal fields protected they should give many years of trouble free service.  Property owners are required to have their Septic tanks inspected at least every three years or have their Septic Systems inspected every six months by part E.5.6.1 of Auckland Council’s Unitary Plan.

If these tanks are not pumped out on a regular basis, settled solids build up, and leave inadequate space in the tank for proper treatment and retention of incoming material.  Odours result and in extreme cases the sludge solids can migrate into the drainage field causing field failure.

How do Septic Tanks work?

All liquid wastes from the house are directed via the gully traps to a septic tank, which should be large enough to hold all wastewater produced from the household for at least 48 hours.  During this period of time two things happen.  Micro organisms living inside the tank digest the nutrients contained within the wastewater, breaking them down into simpler compounds.  This digestive process produces gases, which float some of the lighter material to the surface of the tank, forming a scum.  Settling of indigestible material forms a layer of sludge at the bottom of the tank.  In between the sludge and the scum, water in the settling zone gradually becomes more purified and moves, after the 48 – 72 hours, on to the disposal field.  Over time sludge and scum build up, and the settling zone becomes progressively smaller.  Sludge and scum must be removed on a periodic basis to ensure the continued working of the tank.  Such removal should be an entire removal,  and is facilitated by lifting the lid of the tank and vacuuming out the entire tank contents.  This lid should be easily accessible and protect the tank from stormwater ingress.  In older style systems that are deeply buried it may be necessary to bring access to ground level by the fitting of a concrete riser.

More modern septic tanks have a removable filter by the outlet.   The filter stops larger objects making their way into the disposal field and creates another site for digestion to take place, thus improving the quality of the water leaving the tank.   This needs to be rinsed our every six months or so to removal accumulated biomass and prevent the system from blocking.  Some septics have pumps or dosing syphons feeding the disposal field, others rely on gravity. Taking good care of the soil in the drainage field is paramount as the soil microbes also work to further digest and purify the wastewater.

Do’s and Don’ts

Do:

• Have your tank desludged every three years by a certified hazardous waste contractor

• Keep solids, including food scraps, coffee grounds, tampons, wipes and condoms out of your wastewater

• Check your cleaners are OK for septic tanks (will be on label). Use biodegradable soaps and cleaners.  Do not use blue flush in the toilets

• Take showers instead of baths

• Install water saving devices, practice water conservation.

• Wait for a full load before using the washing machine, and try to stagger your washing through the week rather than doing it all on the same day.

• Divert stormwater from your disposal field and tank area

• Ensure the cleaning lid to your septic tank is easily accessible

• See filters are cleaned every six months

• Employ a proper service agent to do six monthly maintenance checks on package treatment plants

• Take care not to damage dripper lines with lawnmowers, weed eaters etc

Don’t

• Pour harsh cleaning chemicals down your drain as this may kill off the bacterial colonies inside the septic system causing a significant reduction in treatment

• Put excess food wastes, oil or grease down your drains. Remove oil with a paper towel and place it in the rubbish instead

• Park vehicles on any part of your treatment system or disposal field

• Put bleachers, disinfectants, chemicals or paint down the drain

• Connect rain gutters, water tank overflow  or stormwater to septic tank

• Grow deep rooting trees near the septic tank or drainage field

• Let weeds block your dripper lines

• Allow children to play in the disposal field if at surface level

General guides

Specific System Guides