What are the essential details required on septic tank application plans ?

[Callum EHO]

PREPARING A SEPTIC TANK APPLICATION:
STEP 1: Consult with a local plumber regarding siting of a suitable septic system and if necessary pick up an aerial photograph from Council to assist in the preparation of a site plan. (Contact Council). Note that the plumber may charge for this initial application preparation service.
STEP 2: Lodge the application along with the minimum required documentation below.

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Completed application form and appropriate fee (see fee schedule attached)

1 current copy of land title (current to within 2 months)

1 copy of property plan (for rural properties greater than 1 hectare)

1 copy floor plan to scale and clearly showing dimensions

1 copy of a clear and accurate septic site plan (or details drawn on an aerial photograph) to scale indicating the following features:

· position of all streets and laneways adjacent to the property.

· position of all existing or proposed vegetation (bushes and trees) on the site. (if not on aerial photo)

· locations and dimensions of all existing or proposed: buildings, garages and sheds, tennis courts, streams, dams, bores, wells, water tanks, fences swimming pools, excavations, driveways, storm water drains, water pipes, power & phone lines, existing septic systems, tree canopies, garden beds landscape features & easements that are located on the property or up to 60 metres downhill from lowest trench.

· location of the proposed septic tank system including all waste water pipe work from the house and all plumbing fixtures, and the liquid capacities of septic tanks.

· label the position of North. (unless it is a Council aerial photograph which is always the top of the page)

Is there a sign or number on the property?

Are gates to property locked? If locked, please advise where key can be accessed for entry.

The position of proposed building corners have been clearly pegged out.


Does anyone else have any other additions or improvements to add to this ?

[Callum EHO]

The wastewater irrigation area is to be drained to Council’s satisfaction. The only situations where cut-off drains are not required is on the peak of hills, where there is a driveway or building cut with its own site drainage that is going to divert surface run-off or on sites with extremely sandy soil,

A good Land Capability Assessment will detail the type, depth and location of cut-off drainage. Sometimes on steep unstable sites an engineers stability assessment is required to ensure cut off drains are not going to cause a land slide. On other sites it is so flat and there is such poor drainage and locations to drain to that mounding is required of the whole wastewater irrigation area. Cut-off drains too close to a mound on a flat site can be counter productive and cause contamination of standing stormwater.

On all other sites other than the able then suitable "cut-off" drains must be provided to prevent any surface and/or sub-surface water from entering the absorption field. Either a backfilled trench drain or open graded spoon drain may be used between 2 and 4 metres uphill from the first trench provided there is no risk of wastewater entering the cut-off drain. Either option requires the drain to be bedded into the natural stiff impermeable clay by a minimum of 100mm and graded to at least 1:100;

So remember - a cut off drain has to be able to drain away water during rainfall events - not back up and flood the wastewater system. It also needs to be close enough to protect from rain running onto the wastewater dispersal area but far enough away and up hill enough not to inadvertantly pick up wastewater and deliver it off site into waterways.