Attachment K - HSTP Design

5.0 DESIGN RECOMMENDATIONS

We recommend the installation of a 10ep (min capacity) domestic wastewater
treatment plant to treat the domestic wastewater to an advanced secondary quality.

If the integrity and serviceability of the existing Taylex treatment plant is confirmed
we recommend its ongoing use with appropriate monitoring, maintenance and
servicing.

The treated effluent is to be pump-dosed into and along the fixed low pressure heavy
droplet spray irrigation system.

The number of spray outlets and type of spray outlet will be confirmed onsite prior to
or during commissioning of the facility and may require isolating or dosing valve
mechanisms.

This will help the Land Application Area receive treated effluent and residuals in a
manner and at a rate that enables their further treatment by natural in-soil stabilisation
processes so that the resulting clarified carriage water is environmentally and
hygienically acceptable for groundwater infiltration or evaporation and plant
transpiration into the atmosphere.

The final location of a new treatment plant will be determined on-site by variable
consequences (eg finished floor levels, distances, allotment configuration and
topographical constraints) over which we have little control. We recommend further
consultation to determine the adequacy of the final location of the treatment plant at
the time of, or prior to construction of the proposed dwelling.

Notwithstanding the final location of the treatment plant/tank and the Land
Application Area particular attention should be paid to protecting any, or all pipework
below driveways, access tracks, or such trafficable areas.

Our recommendations do not preclude other or additional Land Application Facilities.

Wastewater Treatment Systems and Land Application Facilities should be designed to
remove as much nitrogen as possible by ammonification, settlement in sludge,
denitrification, long residence times or plant uptake.

Water conservation implementation will reduce the hydraulic load on the Land
Application Facility and subsequently improve its performance and serviceable life.

Effluent quality from the treatment plant must comply with the criteria presented in
the Queensland Plumbing and Wastewater Code and AS/NZS 1547-2012 On-site
Domestic Wastewater Management and be confirmed with the regulatory authority.

Treated effluent shall be filtered before delivery to the Land Application Area. All
filters shall be checked and cleaned regularly, or as required.

 

Unearthed Geotechnical P/L. 6 Design Report 023-038