Effluent Disposal Report

5.1 Installation Notes

All installation works, components and fittings must comply with AS/NZS 1547-
2012 On-site Domestic Wastewater Management, and the Queensland Plumbing and
Wastewater Code, and the local authority. All installation works, components and
fittings must comply with Advanced Enviro-septic™ design & installation manual.
The Advanced Enviro-septic™ pipes must be stored and installed adequately to
prevent contamination of the fabric.

Soils are susceptible to damage during the construction and installation processes.
The natural integrity of the existing soil conditions of the Land Application Area must
be preserved at all stages of the proposed development. Damage to the existing soil
profile must be avoided. The laying of the system sand and sand bed extension must
occur immediately after excavation. The laying of the system sand and particularly
the sand bed extension must be performed without compaction by wheeled vehicles or
machinery.

This facility must not be constructed or installed during or immediately after periods
of wet weather and water must not be allowed to enter the excavation during
construction.

When excavating for the Advanced Enviro-septic™ pipes excavate in small bites
using a bucket fitted with ripper teeth to preserve the permeability characteristics of
the natural soil. Scarify/rake all smeared excavated surfaces. We recommend
ripping the base of the entire excavation, along the contour and parallel to the lay of
pipes, to a depth 200mm before backfilling with sand. We recommend the
application of dolomite/gypsum at a nominal rate when preparing the existing soil.
This will assist with both plant growth and pH control (further applications may be
required during the serviceable life of the Land Application Area).

Particular care should be taken with the layout and construction of supply line
trenching/pipework, as with all drainage, plumbing and electrical trenches to inhibit
surface water infiltration along and into the Land Application Area. If necessary all
supply line excavations and trenching shall be backfilled with interceptors.

Particular care should also be taken with the layout and construction of the Land
Application Area trenching/pipework so that released effluent cannot travel back
along trenching causing excessive soil moisture in some areas.

As with all effluent disposal in Land Application Areas, the release of effluent along
the contours (i.e. level) is both elementary and critical to achieve efficient spread and
even disposal. The trenches/beds must be constructed level.

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.

 

Unearthed Geotechnical P/L. 8 Design Report 020-212