Human Waste Transformed Into Crop Fertiliser

Rows of two-month-old sweet corn planted by Mariam Yajid are thriving luxuriantly, with leaves that are not only broad but also a deep, healthy green. The secret lies in a ‘black powder’ sprinkled weekly along the planting beds.

“Don’t be surprised, but this black fertiliser is actually biosolids processed from human waste and turned into compost,” shared Mariam, 55, one of 20 participants in the Insentif Pendapatan Rakyat programme under Koperasi Kebuniti Selangor Berhad (Kebuniti), in an interview with Bernama recently.

During a visit to Kebuniti Agropark U12, Shah Alam, Bernama found that all the crops, including papaya, eggplant, chillies, water spinach, spinach and bitter gourd, were thriving. In fact, according to Mariam, not only did the plants grow faster, but the yields were also higher.

“At first, when I found out it came from human waste, I was shocked. But once I understood that this biosolid fertiliser is safe to use, my mindset changed and I started applying it to crops such as corn and eggplant,” she said, explaining that the compost is mixed with NPK fertiliser (nitrogen, phosphorus and potassium) before being applied at the base of plants.

WASTE MANAGEMENT A GROWING CHALLENGE

Operating continuously, the national sewerage system channels wastewater — including human faecal matter — to treatment plants, producing biosolids that were previously disposed of at landfills or managed as scheduled waste.

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However, cost inefficiencies as well as mounting landfill and waste management issues have prompted national sewerage company Indah Water Konsortium Sdn Bhd (IWK) to seek alternative methods to better manage the biosolids.

As a result, in 2022 IWK implemented a pilot project to process biosolids into organic fertiliser. While the idea may sound unpleasant or uncomfortable to some segments of society, IWK notes that countries such as China, the United States, Australia, Japan and several European nations have long used biosolids derived from human waste as soil conditioners, subject to stringent safety standards.

RICH IN NUTRIENTS

Elaborating further, IWK Chief Operating Officer Ir. Mohd Taufik Salleh explained that biosolids are fundamentally different from raw human waste, as they undergo multiple treatment stages, including dewatering, biological decomposition and pathogen reduction.

“Wastewater is treated using aerobic biological processes at IWK sewage treatment plants. This process produces a downstream product known as sludge.

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“Sludge consists of a combination of flocs (undecomposed residues) and microorganisms that help break down organic pollutants, eventually forming a mass that settles and separates from treated wastewater in sedimentation tanks.

“The sludge then undergoes several further treatment stages, including thickening, stabilisation and drying. These processes ensure that the final product — biosolids — is stable, odourless and safe for reuse in accordance with prescribed standards,” he said in a written reply to Bernama recently.

He added that biosolid fertiliser is rich in organic matter, nitrogen, phosphorus and essential micronutrients, with an NPK value of 1-1-6, making it highly suitable for agriculture, landscaping, soil rehabilitation and forestry.

“Before the initiative to reuse biosolids as organic fertiliser, biosolids generated from sewage treatment processes were disposed of at sanitary landfills or biosolid disposal sites approved by the Department of Environment, involving high operational and logistics costs.

“The biosolid fertiliser, also known as IWK organic fertiliser, is driven by the need to manage biosolids more sustainably, reduce reliance on final disposal, and support the circular economy and environmental sustainability agenda,” he stressed.

RM4 MILLION INVESTMENT

With an investment totalling RM4 million, IWK, together with the Department of Sewerage Services (JPP), launched a pilot project to produce the organic fertiliser at the Titiwangsa Regional Sewage Treatment Plant in Kuala Lumpur. The initiative also involved collaborations with Universiti Putra Malaysia, to assess the fertiliser’s effectiveness on crops, and Universiti Teknologi MARA, to support marketing efforts.

As part of the project, a dedicated facility was built and research and development (R&D) was carried out. A year later, in 2023, production of the organic fertiliser began, with supplies delivered to Kebuniti.

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“In 2025, this plant processed around 100 metric tonnes of biosolids, producing about 60 metric tonnes of organic fertiliser. At present, we produce about five tonnes of fertiliser a day, but production capacity can be increased in line with needs and demand,” said Mohd Taufik.

He said the initiative also has the potential to be expanded to other plants, subject to site suitability, technical requirements and cost-benefit analysis.

“The main purpose of using organic fertiliser derived from biosolids is to support environmental sustainability through sustainable management, reduce waste sent to landfills, and close the resource cycle (circular economy),” he stressed.

FROM PLANT TO PLOT

To test the fertiliser’s effectiveness and safety in real-world conditions, IWK partnered with implementation partners including Kebuniti, a community agriculture established in 2020 to combat urban poverty, train participants and aspiring agro-entrepreneurs, and promote eco-tourism in Selangor.

Having used IWK organic fertiliser since 2023, Kebuniti chairman Datuk Dr Mohamad Roff Mohd Noor said participants were initially sceptical.

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“The initial concern was from the syariah perspective… can we use fertiliser sourced from human waste? Especially since the Malaysian Standard (MS), namely MS 1517, states that organic fertilisers may use all types of sources except pig and human waste,” he said.

(MS 1517 is Malaysia’s national standard for organic fertilisers, setting quality requirements and technical specifications for fertilisers produced or sold in the country. It serves as a reference for manufacturers and certification bodies such as SIRIM.)

Commenting further, Mohamad Roff, a former Director-General of the Malaysian Agricultural Research and Development Institute (MARDI), said efforts to obtain MS 1517 approval had been underway for more than a year.

“We (IWK and Kebuniti) have presented the related studies and findings to the Department of Standards Malaysia. It does take time (to remove human waste from the list of prohibited sources for organic fertiliser),” he explained, adding that from the early stages, Kebuniti had been using IWK’s organic fertiliser for all types of crops in their farmland.

“At the beginning, participants were sceptical, but after understanding the production process, they agreed to try it. Interestingly, unlike initial assumptions, the smell is not as strong as imagined because it has gone through a treatment process.

“IWK’s organic fertiliser helps restore and loosen the soil, making it easier for plants to absorb nutrients. The plants grow well and yields are high,” he said, adding that IWK’s organic fertiliser comes in two forms — powder and pellets.

CHANGING PERCEPTIONS

Although early results are encouraging, the real challenge for biosolid fertiliser lies not in technology, but public acceptance, as many people associate fertilisers derived from human waste with disgust or fear of disease.

Addressing this, Mohamad Roff said public perception could be improved by expanding use among farmers through collaboration with agencies such as the Department of Agriculture and the Farmers’ Organisation Authority.

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“Chicken manure, goat manure — what’s the difference compared to human waste? It’s essentially the same.

“For those worried about disease, we’ve sent samples for laboratory analysis. Microbial tests showed none, and there are no heavy metals. So it’s safe.

“Toxicology studies conducted by SIRIM on laboratory rats showed no mortality, no signs of toxicity or behavioural changes. All test animals remained healthy and gained weight after being administered fertiliser extracts,” he explained.

Kebuniti also distributes visitors with complimentary fertiliser samples and so far, there have been no complaints.

“No one refuses it — they just take it.

“I personally have no problem eating vegetables grown using IWK organic fertiliser,” he said.

Kebuniti uses 15 tonnes of IWK organic fertiliser over six months across six hectares of farmland, including flowers, ornamental plants, landscaping and vegetables.

He believes negative perceptions can be overcome through continuous public education, particularly regarding treatment processes and safety assurances.

SYARIAH RULING

From an Islamic perspective, the 126th Muzakarah Committee of the National Council for Islamic Religious Affairs Malaysia, which convened from Feb 25 to 27, 2025, ruled that producing and using organic fertiliser derived from safely processed IWK biosolids is permissible.

The Pahang Islamic Religious Council also issued a fatwa allowing the use of biosolids from treated sewage as raw material for organic fertiliser production.

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According to the official website of the Pahang State Mufti Department, the State Syariah Advisory Committee Meeting No. 02/2025 agreed that producing and using safe and beneficial biosolid-based fertiliser is permissible.

However, the committee advised that crops coming into contact with the fertiliser should be washed before consumption, as the fertiliser is categorised as najis (filth).

Commenting on this, Mohd Taufik said the recognition signifies positive acceptance of IWK’s efforts to ensure all treatment and production processes comply with syariah guidelines and safety standards.

“This recognition is very meaningful for IWK, as it not only confirms that our biosolid fertiliser is safe to use, but also instils confidence among the public, particularly Muslim consumers, in our sustainable wastewater management efforts,” he said.

A MARKET OR JUST A WASTE SOLUTION?

Another key question is whether biosolid fertiliser has commercial potential, or if it merely serves as an internal waste-reduction solution.

At present, the fertiliser has yet to be commercialised. Factors such as public perception, lack of specific certification, and competition from chemical and other organic fertilisers pose challenges. However, lower production costs compared to chicken and goat manure fertilisers, along with a steady supply of raw materials, offer distinct advantages.

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In urban agriculture, landscaping, ornamental plants and degraded soil rehabilitation, biosolid fertiliser may find a niche. It also has the potential to reduce dependence on imported fertilisers — an increasingly pressing issue amid rising global fertiliser prices.

To ensure safe expansion and acceptance, strong policy support is needed, particularly regarding MS 1517.

For IWK, biosolids are not merely about innovation or value creation, but necessity. Every day, sewage treatment plants nationwide generate large volumes of biosolids that must be disposed of.

Considering cost, space and environmental risks, converting biosolids into organic fertiliser may well be the most practical solution for all.