wastewater design

Correct pipe layout and Land Application Area construction/installation is an essential
part of our recommendations and design. If the site is not prepared in accordance
with our design, or is prepared inadequately or is prepared poorly, inefficiencies may
occur and we do not take responsibility for the consequences in such cases and we
will make an additional charge if as a result, more testing, re-designing or re-writing
of the report is necessary.

Noosa Council may require an inspection for certification to be carried out before
final approval can be issued.

Unearthed Geotechnical P/L recommends an inspection for certification be carried
out by the designer prior to commissioning, and preferably during construction, to
ensure code compliance and that ‘best practice’ principles have been utilised.

As with all use of sand or distribution aggregate for wastewater treatment and disposal
it is very important to restrict the ingress of finer particles to maintain the integrity of
the expected performance outcomes of the sand or distribution aggregate. To this end
Unearthed Geotechnical P/L suggests the entire bed of sand or distribution aggregate
be covered in an appropriate and approved geotextile fabric to restrict such ingress of
finer soil particles. This will help to maintain the expected performance outcomes of
the sand or distribution aggregate. Without the use of an appropriate and approved
geotextile fabric it is probable that the integrity of the sand or distribution aggregate
will likely be compromised.

The treatment plant/ tanks traps and associated fittings shall be

e constructed of durable materials with expandable and/or flexible connections,

e positioned correctly in relation to boundaries, buildings etc to provide an angle of
repose of at least 45 degrees between the bottom of the footing system/excavation
and the base of any associated excavation

e watertight and capable of withstanding loads imposed on the roof and walls

e installed so that flotation will not occur when the tank/s is empty

e — installed on a stable base and to prevent surface water infiltration.

e located with good clear access for servicing and desludging operations

e located within a designated area to enhance its amenity

e be protected from roof water/tank discharge, surface water flow and/or seepage

e installed and operated in accordance with regulatory guidelines.

The supply lines to the septic tank must be adequately vented with mosquito proof
cowls fitted to all vents.

The Land Application Areas shall

e not be located on land prone to water logging or subject to floodwater inundation
e be sited to be open to prevailing winds and not totally shaded from sunlight

e — be protected from roof water discharge, surface water flow and/or seepage

e have no runoff or seepage of the applied effluent beyond the designated area

e be regularly inspected and maintained

e have the mandatory signage prominently displayed

e have boundaries (fence) to deter grazing animals and casual pedestrian traffic

 

Unearthed Geotechnical P/L. 9 Design Report 022-003