Deuce to manure | Daily News

Deuce to manure

Fertilzer Pellets-Co-composting
Fertilzer Pellets-Co-composting

Best solution for waste pollution:

Sri Lanka has done very well to achieve the United Nation’s Millennium Development Goal of increasing toilet access for its people: 99 percent of the population has access to some form of toilet. Unfortunately, there continues to be little consideration of how the human waste, or faecal sludge, that ends up in those toilets, is processed.

Only between 1.9 to 2.6 percent of Sri Lankans have access to traditional sewer systems, and the rest of the population depends on pit latrines and septic tanks for waste storage.

In and of themselves, these storage systems are not problematic, but it is worrisome that just 10 percent of the faecal sludge in these latrines and tanks is extracted by septic trucks. The other 90 percent of the sewage is sealed underground or disposed of in some way or another, and is often simply dumped in the surrounding environment, according to Dr. Sudarshana Fernando, a resource recovery and reuse expert at the International Water Management Institute (IWMI).

Such disposal methods are not ideal, as they can lead to groundwater and environmental contamination. Sri Lankans drink both ground and surface water, and it goes without saying that consuming polluted groundwater can lead to illnesses. Faecal contamination-related diseases are a major cause of hospitalizations across the country.

Despite that, traditional gravity sewer systems negate the aforementioned disposal difficulties, it is unlikely they will be adopted island-wide since they are so expensive. Studies have shown that increasing sewerage coverage is cost ineffective, as it is very difficult to operate the systems well enough to make up for the necessarily steep initial expenditures.

The government is, however, investing in expanding some sewer systems, and it expects 3.75 percent of the population to have access to sewers by 2020. The rest of the population, however, will continue to use septic tanks and pit latrines.

Instead of focusing investments in sewer systems, money should be spent to improve waste transport and disposal services for those who do not have access to sewers, according to Dr. Soumya Balasubramanya, a researcher in Environmental Economics at IWMI.

“You have to think about the whole waste management chain. It’s not just about the toilet. You have to consider what happens after the toilet fills up. You have to ask how do you pull the waste out, how do you transport it, where do you transport it to, and what do you do to treat it,” she said.

According to IWMI researchers, just One percent of the country’s sewage is treated, and this is due to both transport and processing deficiencies, so Balasubramanya’s questions are certainly pertinent. A financially feasible mechanism for emptying the pits and latrines and moving the sludge to treatment plants has not yet been found.

Though initially expensive, investment in waste management can pay massive dividends, especially for the poor. The World Health Organization (WHO) estimates that every dollar invested in sanitation yields an average benefit of $5.5, with the two main benefits being improved health and environmental outcomes. The importance of these for the poor cannot be overstated, as they spend less time being sick, less money on healthcare and more days earning money.

“When the government puts money into improving sanitation and waste water disposal, it is distributionally progressive,” said Balasubramanya.

But a central waste management problem is procuring sufficient investment for the necessary equipment and facilities to process waste. Very often governments are reluctant to invest in these systems because they think they will have to bear the full costs.


Waste Management in Anuradhapura

The waste management situation in Anuradhapura lays bear the troubles Municipal Councils across the island encounter when removing faecal sludge.

The Anuradhapura Municipal Council (AMC) is responsible for extracting and transporting the waste from 16,768 housing units as well as 3,813 business entities. This is clearly a gargantuan task, and the AMC has just two gully bowsers capable to cleaning the pit latrines and septic tanks and transporting waste.

The Council’s clearance capabilities are stretched to, or beyond capacity and they respond only to emergencies.

“What happens currently is that we are called by a household or a commercial enterprise when the septic tank is full and overflowing. The Municipal Council then dispatches its gully bowsers to clear the tank,” said Anuradhapura Municipal Commissioner Ajantha Gunawardene.

Each of the bowsers has a capacity of 4,000 litres and residents pay Rs. 3,635 for the extraction of each load, while business entities are required to pay Rs. 4,660 per load.

According to Gunawardene, the waste is ferried to a waste treatment plant where it is converted to fertilizer for gardens and landscaping projects. But, it is unclear how only two trucks could clear and transport so much waste in such a large area.

Gunawardene acknowledged that the current method of waste extraction and transport leaves much to be desired.

“We are in the process of educating people and creating a proper procedure for the collection of waste water. We want it to be more systematic and are working on how best to make it so. Also, we are looking at giving incentives to locals to encourage them to be systematic in their waste management,” he said.

The AMC is investing in a faecal sludge treatment plant; a new treatment plant will open on July 1st in Anuradhapura, on BuddhagayaMawatha. It was funded by the Provincial Council and designed and constructed by the Central Engineering Consultancy Bureau (CECB).

But it remains to be seen how useful a new treatment plan will be without improved waste water transportation services. As the researchers at IWMI pointed out, all aspects from emptying tanks to transport to treatment to reuse, must be developed simultaneously in order to facilitate improvements in the overall services.

You cannot treat sludge if you cannot transport it, after all.


Subscription Service?

According to Balasubramanya, better waste management outcomes can be achieved by coupling public sector investment with money raised from stakeholders. She recently authored a paper in the journal PLOS ONE on her work in the Bangladeshi sub-district of Bhaluka, where she analysed the benefits of people paying small fees for an efficient and safe waste water transportation service.

The study found that splitting the cost of waste water removal through monthly payments could make the services more affordable, more efficient, and later lead to improved faecal treatment and conversion into fertilizers or energy sources.

By examining the economics of faecal sludge collection and transportation in Bhaluka, Balasubramanya found that the cost to empty a pit latrine was about $13 dollars, or about 14 percent of the average family’s monthly income. Families struggle to pay such a sum for collection, even though these latrines must be emptied only once every three to four years.

But, by paying 0.31 dollars per month over the same period, about what they spend on mobile phone or cable services, families could subscribe to the faecal sludge removal and transportation service.

Though 0.31 seems a small monthly cost, the study discovered that families were willing to pay just half of it to begin with.

“We found that dividing the amount families were willing to pay for waste removal, about 6.5 dollars per pick up, over twelve instalments would be easier on the households,” Balasubramanya said.

Over time however, the government could increase the amounts they raise from the monthly instalments until the transportation finances itself. Furthermore, private citizens’ contributions can open the door for the public sector to invest in waste treatment or reuse solutions.

Co-composting, or mixing low-nutrient organic household waste with nutrient-rich faecal sludge, is a practical treatment solution. The process kills bacteria and the composted material can be used directly as fertilizer.

The compost can also be converted into fertilizer pellets, which are safe and organic substitutes for chemical fertilizers.

In Sri Lanka, there are over 110 compost stations and some of them have started co-composting.


The Sri Lankan Context

Though her research focused on rural Bangladesh, Balasubramanya thinks that her results could be replicated in Sri Lanka. The World Bank, moreover, has found that Sri Lankans are happy to pay subscription services for systems that come and collect waste.

“We think there will be similar results elsewhere. Nobody wants faecal sludge in his or her backyard. Everyone is very happy to have a regular service that comes like clockwork, takes the waste away, and that you don’t have to worry about. I think if you are able to demonstrate credible services for people, they are willing to pay for them.”

“No, they cannot pay full costs, but the whole purpose is you try to extract what you can, what is feasible, from private households who are producing this waste, and then the government covers the rest,” she said.

If transportation costs are at least partially covered, it paves the way for the government to invest in treatment and reuse, which then lead to improved environmental standards and health outcomes.

“From a political economy perspective, this shows that poor populations are demanding better environmental amenities and that people value clean environments. They don’t want their surroundings to be polluted by waste,” Balasubramanya said.

Gully Bowser

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