Biodigesters in Cambodia: Protecting Health and the Planet


On the outskirts of Battambang City, there are vast fields of rice, smallholder family farms, lots of cows, and, thanks to Mr. Sieb Minh, owner of Sre La-Or P4G Co. Ltd, a growing number of life-changing biodigesters.

In farmyards along the roads, cows munch on grass and hay and produce  an impressive amount of dung.  Left on its own, all of that animal waste can harbor dangerous pathogens such as E. coli, Listeria, and Cryptosporidium. It’s a health hazard to both humans and livestock. 

 At the same time, many rural households in Cambodia cook over traditional wood and charcoal-fired stoves, creating unsafe levels of home pollution, risk of respiratory disease, and serious accidental burns.  Additionally, large-scale foraging for fire to fuel cookstoves exacerbates deforestation.

Other families spend scarce money on petrol to drive a significant distance to purchase canisters of liquified petroleum gas (LPG).  These canisters sometimes leak toxic fumes into the home, creating health risks for families, especially women and young children.  

 Cambodia’s Ministry of Agriculture, Forestry and Fisheries, working with the Netherlands Development Organisation (SNV), devised a plan to address both of these problems with one solution: the National Biodigester Programme. 


Essentially, a household biodigester is a tank installed in the ground into which the family feeds cow dung and other bio-waste and mixes it with water. It undergoes an anaerobic digestion process to produce biogas. An underground pipe is installed from the tank to send the gas directly to the stove in the cooking area. The by-product, a slurry,  is used as a natural fertilizer supplement. 

So far, working with partners like Mr. Sieb, the programme reports the installation of just over 28,000 biodigesters. That’s around six percent of potential households, so there are clear investment and growth opportunities for entrepreneurs.

Mr. Sieb has so far installed about 300 biodigesters in Battambang and Pailin provinces.  

An individual family can expect to pay around $400 USD for a biodigester after the government subsidy of  $200 USD.  That is a significant sum of money for a provincial farmer; very few have it readily available, making Mr. Sieb’s job all the more challenging. 

This is face-to-face, not online, marketing. 

“I start with meeting the commune chief, and we invite local farmers to come to a meeting to hear how it can be very good for them in the long term,”  Mr. Sieb said. “Then, I go to meet with the individual farmer in his home. Sometimes they  tell me they want to buy the biodigester, but they do not have enough money.”

He works with the farmer to calculate how the investment will pay for itself through savings on petrol, LPG purchases, and chemical fertilizers. They might look at healthcare expenditures resulting from smoke-induced respiratory illness and discuss losses related to the illness of livestock from unsanitary conditions.  They add in the time saved by not going to the market or foraging for firewood.

 “I want to help more farming families save money and be healthier,” he explains. “I’d like to be able to install five or seven biodigesters each month. And, I’d like to expand my business by purchasing unused slurry from my  bio-digester customers.”  

He can package the slurry, which reduces the use of chemicals and preserves the integrity of the soil and sell it at market for an additional profit.

Right now, he employs five other people, and if his customers refer another purchaser to him, the customer gets a $20 USD commission.  Everybody wins:  the farming family, Mr. Sieb, the environment, and the cows.