Our Farm Part 3

Natural Waste Water Treatment Facility

Sustainable agriculture is anchored on the minimizing the impact to the natural environment.  A pig farm's waste water effluent if not properly handled and treated can result in significant impact to its surrounding environment.  Piggery waster water have very high chemical oxygen demand (COD) and biological oxygen demand (BOD) due to the presence of huge amount of organic and inorganic compounds in it.  The biggest contributors to the high COD/BOD of the waste water from pig farms are ammonium and the phosphate compounds.  In a lot of pig farms, the waste water goes straight into a body of water, normally a creek or a river.  This results in severe pollution of the body of water as the available oxygen gets used up by the waste water leaving very little for use by the existing ecosystem.

In some cases, the waste water are diverted to rice fields.  Whilst the plants can use the organic nitrogen compounds in the waste water stream, the excessive amounts of phosphates has detrimental effects on plants and on the soil phosphorous status.

At Sunshine Spring Nature Farm, we consume a huge amount of water as we continuously supply water to the wallowing ponds of the pigpens to ensure organic wastes do not accumulate.  This continuous flow of waste water needs be treated before discharge to the creek at the edge of the property.

Natural waste water treatment facility of the farm using green algae, duckweed, azolla and kangkong.

The way we manage our waste water is by natural means.  We use plants and algae to treat our waste water before it is discharged to the creek. Our natural waste water treatment facility is comprised of four treatment levels.  The top level is the settling pond.  In the settling pond, the waste water is acted upon by bacteria and algae.  The green algae are harvested on a regular basis and fed to the fishes (tilapia) in the nearby fish pond.  Water from the settling ponds flows to the second level - the duckweed pond. The duckweed pond is the ammonia sink of the treatment facility.  Here, ammonia and nitrogen compounds are used by the duckweed for rapid growth.  From the duckweed pond, waste water flows to the azolla pond.  The azolla pond is the phosphorous sink of the facility.  Phosphates are the single biggest determinant of the growth of azolla.  The higher the phosphate level, the faster the growth of azolla.  Unlike duckweed, azolla does not need the ammonium ion in the waste water as it can manufacture its own organic nitrogen.  The last level is the poshing pond or the kangkong pond.  Th kangkong or water spinach, absorbs whatever residual organic compounds that are left in the water flowing to this pond.

Our natural waste water treatment produces significant amount of biomass that we use to supplement the feed requirement of the pigs, fishes, chickens, ducks and goats.  On a daily basis, we harvest more than 100 kilos of duckweed and azolla and about 25 kilos of kangkong.