Page 19
RISK IN UNUSUAL SITUATIONS - Cont...
The Compost gets too cold
Should the compost pile fall below 6°C for an extended period (2-3 months) composting will slow to the
point that it’s retained time may not achieve full composting. This risk is mitigated by:
• The design has natural insulation which helps retain composting heat in cold climates.
• The Installation Instructions stipulates that in cold climates the Rota-Loo must be installed in a solar
collecting area and with further insulation. This allows the system to gain and retain heat to continue
the composting process even in cold periods.
•
The Rota-Loo capacity design anticipates 12 months composting time, which in theory will ensure full
composting as low as 2°C (see Figure E1, AS/NZS 1546.2:2008 Appendix E) in with a safety factor of
about 50%.
In the rare event that the composting process has stopped due to low temperature and lack of
compostable material, it can be restarted by adding compostable material and a dose of Bio-Stimulant.
The Compost gets too humid
If the compost gets too humid, (above 70% moisture) the composting process will become anaerobic
which will be noticeable by the odour produced. This event can occur for a number of reasons and is
addressed in the Troubleshooting Guide on Page 15.
It is important to maintain aerobic composting and the Rota-Loo design uses a number of features to
separate and evaporate the liquids from the solids for this purpose. Should the composting become
anaerobic due to excessive liquid (high humidity of the pile) there is no immediate health risk. The odour
will be unpleasant which will encourage rectification. The fan-driven ventilation system will clear any
produced methane.
The Compost is removed too early
This should not occur - the design provides for a factor of safety in time for composting. In the case of
very high use when compost may be removed before the designed 12 months, instructions stipulate
storing in additional bins (Operations Page 13).
The Operations Manual instructs to bury the composted waste when emptying the bin and using
personal protective equipment (Operations Manual page 13) so in the case that composted waste is
inadvertently removed before full composting, there will not be personal contact or significant health risk.
There is poor drainage of excess liquid
The Rota-Loo ‘tank’ has a significant liquid capacity (to depth of about 150mm) while still being able to
properly drain the composting material pile.
The Excess Liquid drainage point is significantly lower than this level. Should a blockage occur in the drain
point, the high liquid level will most likely cause some anaerobic composting which will produce an odour
that will be investigated - dealt with in the Troubleshooting Guide (Page 15)
The Rota-Loo is Flooded
The Rota-Loo is not intended to be installed underground or submerged. In the event of a major flood
event it may be possible that the water level is above the base of the Rota-Loo for a period of time. The
Rota-Loo is designed to be air tight to improve ventilation and will therefore resist ingress of water so in
minor events the waste material should be protected from flooding.
If significant water does enter the Rota-Loo (to above the turntable deck) the water needs to be
considered contaminated. The sealed design of the Rota-Loo should prevent leakage and thus
contamination of the surrounds but the Rota-Loo must be pumped out by a septic tank specialist and
washed and reset before restarting use.
If the installation is in an area that may experience flooding, consideration should be given to
adequate drainage of the area around if necessary securing the Rota-Loo to prevent floating in a
flood situation (noted in Installation Page 7).
