STANDARD OPERATING PROCEDURE -
Composting
INTRODUCTION
In the long term composting is the best way to reduce and reuse green waste. Composting also provides a valuable
source of nutrients for growing plants. Controlling the temperature, moisture content and carbon to nitrogen ration
of your compost pile is the key to killing weeds and breaking down organic material into useable compost. While
generally a safe exercise, composting can potentially involve exposure to microorganisms, some of which can be
harmful. To minimise this risk it is important to address safety requirements such as adequate PPE and cleanliness.
STEP
INSTRUCTIONS
ADDITIONAL GUIDANCE
Layout
Adequate composting requires at least two bays
with three sides.
Healthy compost:
When one bay is full, turn and let “cook” for
about three months while filling up the second
bay.
 has a crumbly structure
Cover active bays with a weed mat
 is a brown to dark brown colour
Manage moisture content by covering with a
waterproof tarp
 should be moist but not soggy
 looks and smells good.
 is fine and smooth to the touch
Unhealthy compost:
 smells terrible (often like ammonia)
 looks slimy and wet
 contains undigested chunks of organic material
1. Place layer of
green waste in
bay.
As a general rule, 2 parts green waste to 1 part
brown waste will provide the required
Carbon:Nitrogen (C:N) ratio
Green waste includes things like plant cuttings,
lawn clippings (before they turn brown) and food
waste.
Assess risk of potential allergic reaction in
sensitive individuals via site induction. Remove
from site if necessary
Disinfect and dress injuries immediately
Standard Operating Procedure Composting Version 1 May 2012
The ideal C:N ratio is around 30:1. As a general rule
the microorganisms that digest compost need about
30 parts of carbon for every 1 part of nitrogen they
consume.
Note that 30 times as much brown waster as green
waste is NOT required to achieve the ideal C:N ratio!
Most organic material is made up of both C and N in
varying quantities.
As a general rule, 2 parts green waste to 1 part brown
waste will provide the required Carbon:Nitrogen (C:N)
ratio
2. Place layer
of brown waste
in bay.
Brown waste includes things like newspaper,
mulch and lawn clippings (after they turn brown).
When stockpiling brown waste take care to
minimise the risk of fires as dry matter can be
susceptible to sparks from cigarettes or welding
equipment
Too much nitrogen will result in a sloppy smelly heap
and too much carbon will mean the heap composts
much more slowly. Compost develops slower in winter
than it does in summer.
Safety recommendations for potential exposure
to microorganisms as per section 1
Disinfect and dress injuries immediately
Healthy compost. Photo: Wikipedia
3. Add a spade
of used soil and
chicken manure,
or blood and
bone.
Chicken manure and blood and bone is to be kept
in closed bins
Minimise exposure to microorganisms
Undertake this step in non windy conditions so as
to minimise the release of airborne particles
Wear appropriate PPE in particular covered
footwear, dust masks and gloves.
If moderately windy, stand upwind of soil and
chicken manure pile.
Safety recommendations for potential exposure
to microorganisms as per section 1
Disinfect and dress injuries immediately
4. Once a
month add half a
spade of lime.
As per sections 1 - 3
5. Once bay is
full turn it once
and let it sit for 3
months until
cooked.
Do not turn when windy so as to minimise the
release of airborne particles.
Adding soil and chicken manure will ensure that there
is enough bacteria in the heap. Diagram: Creek to
Coral
Adding lime ensures that the compost heap does not
become too acidic.
A hot, fast pile (with temperatures up to
140°F/60°C) is obtained when the C:N ratio of all
the materials you add averages 30:1 (50:1 is
adequate for most slower, lower-temperature
piles).
The activity of microorganisms causes the pile to heat
up, which assists in the breakdown processes and, if
hot enough, can kill potentially harmful
microorganisms. (Photo: CAL:ILA)
Standard Operating Procedure Composting Version 1 May 2012
6.
Clean up
Ensure compost bin is adequately covered
Clean equipment and return to shed
Remove gloves by pulling off each hand while still
gloved. This enables the gloves to be removed
without the surface of the skin coming into
contact with the outside of the glove.
Ensure adequate sanitation
Wash hands thoroughly with antibacterial
handwash
Standard Operating Procedure Composting Version 1 May 2012