Our instruments indicated that very fine air-borne ash particulates from the Norochcholai Coal Power Plant were reaching the hills of Nawalapitiya and Colombo in March and April last year. We measured particulate matter so fine that it could lodge inside one’s lungs (2.5 micro-metres abbreviated as pm2.5).  These particulates will diminish rain bearing clouds, will [...]

Sunday Times 2

Norochcholai ash contaminates Lanka’s western atmosphere


Our instruments indicated that very fine air-borne ash particulates from the Norochcholai Coal Power Plant were reaching the hills of Nawalapitiya and Colombo in March and April last year. We measured particulate matter so fine that it could lodge inside one’s lungs (2.5 micro-metres abbreviated as pm2.5).  These particulates will diminish rain bearing clouds, will be toxic to fauna, coat vegetation and crops, and lop years off the life expectancy of those exposed to them.

These unexpected findings arose from two unrelated lines of inquiry – one on the impact of air pollution on clouds and, the other, on the impact of the Coal Power Plant on its locality.

We installed the instruments in Colombo and Nawalapitiya to assess the impacts. In Colombo, the instruments were placed in Cinnamon Gardens (alongside a certified instrument maintained by the US embassy). The air quality here was primarily affected by traffic. In Nawalapitiya, the instrument was kept on a remote hilltop (the Climate Change Observatory of Dilmah Conservation).

In March last year, Colombo and Nawalapitiya averaged pm2.5 of 30 and 15 micro-grams per cubic metre respectively. By comparison, the national mandated limits for particulates for the annual mean is 25 which is lax compared to the US threshold of 15 and Australia’s 8.

Impact of Norochcholai Plant on neighbourhood

In Norochcholai, our instrument was located outside the Coal Power Plant. This plant was inaugurated in 2011 with a 300 MW unit and was subsequently expanded to 900 MW with two additional units. The plant provides up to 50 percent of the electric energy to meet the intensifying wants of the consumers. The maintenance of the plant has been sub-par and the environmental monitoring has not been up to what is required.

Ash and other dust can be carried from the emissions from its three chimneys and from the stacks of ash stored in its yard. This ash can contain toxins such as arsenic and variety of metals. The plant operators monitor emissions within the chimneys well. However, the air quality outside the plant is seldom monitored – maybe as an exercise in ticking off regulatory requirements and in public relations.

On average, 850,000 kg of fly ash is routed to the chimneys via the scrubbers each day – if the scrubbers work well then 90-99 percent may be captured.  This amount increases with malfunctions – there have been more than a score of unplanned shutdowns.   Even if a modest part of this injection of ash (and other chemicals) is carried by air in a given direction, it can have an extraordinary impact on the ecosystem, wildlife, plants, clouds and humans.

In March last year, our Norochcholai instrument indicated an average monthly pollution (35) higher than Colombo (30).  The Norochcholai readings are lower than what the villagers are exposed to as the instrument was kept inside a small building for safety.

Air Quality without the malfunctioning unit?

One of the three power plants had several malfunctioning exhaust air scrubbing units – this plant was shut down from April 11 to 21 last year for repair. The average pollution dropped to around 10 in Norochcholai,   to 20 in Colombo and to 5 in Nawalapitiya.  The pollution did reduce after the repairs to Unit 1 were completed.

Does Norochcholai Air Pollution reach Nawalapitiya and Colombo?

After stumbling on the finding that the Nawalapitiya, readings dropped abruptly with the Norochcholai Coal Power Plant shutdown, we compared the readings from these locations prior to the shutdown – we found out that their undulations tracked one another closely.

The particulates that are carried by air shall vary by the time and location due to the wind and rain in the locality and beyond. Even with these confounding factors, the chance that the readings at Norochcholai and Nawalapitiya tracked each other due to random chance is less than 0.05 percent.  We cannot come up with a viable alternative hypothesis as to why these undulations should be close to lock-step. This is as close as one gets to conclusiveness in this sort of work.

The correlation between observations at Norochcholai and Colombo does not track as clearly to the eye but statistically, the evidence of a relationship is clear and the likelihood of a chance relationship is less than 5 percent.

Colombo has multiple sources of pollution and they camouflage the influence of Norochcholai. Still the evidence is there: with the right wind direction, the Western coast is also affected by the Coal Power Plant emissions –many people in this region are already exposed to high pollution levels.

Our recent analysis, from November 16, 2018 to February 25, 2019, shows that the relationship between measurements in Norochcholai and Colombo is clear to the eye – there is a less than 0.1 percent chance of this being a random correlation.

Why was such long-range pollution transport not anticipated?

The authorities (e.g. The EIA) had not anticipated transport of pollution to the hills and the western coast because of ingrained myths regarding wind patterns.  It was presumed the air pollution for the most part would be carried to the sea from December to February and would be carried to the Northern Puttalam and beyond in other months.

Indeed, the EIA for the proposed Sampur Plant showed alarming ignorance about wind – Financial Time, 20 July 2016 – http://www.ft.lk/article/555835/Is-the-air-pollution-analysis-for-the-Sampur-Coal-Plant-credible).

Wind measurements in several locations within this area show that there is a significant fraction of time when the air blows from Puttalam to the Western Hills and Coast. The wind headed to the hills for 8 percent of the day in March last year.

Despite such allowance for environmental or maybe convenient ignorance, we can see that if the air quality monitoring had been undertaken as required by the EIA, then the power company and the regulators would have been clued in long ago.

The pollution in Sri Lanka is lower than the catastrophic levels in urban India and China.   Yet, the Central Environment Authority (CEA) and the National Building Research Organization (NBRO) have shown that air pollution is rising inexorably in urban centers, where it is already a health hazard –e.g. Kandy city as shown by Prof. Oliver Ileperuma and others at the University of Peradeniya, NBRO and CEA.

Lessons learned

n    We have established that air pollution monitoring is viable at relatively low cost and those entrusted have chosen to operate blindly of the impacts.

n    8,500 kg of ash containing toxins being spewed daily into our atmosphere warrants our attention — even when the plant works as advertised.

n    We have established a long-range impact from air pollution from the plant.

n    The plant operators, regulators and their overseers fail when the plant is operated with  malfunctioning units as was the case in March last year (and probably before).

n    The villagers in the vicinity raise the alarm but their voices have been largely ignored.  There is a moral failure when we compromise the visible health and economic impacts on the villagers for our comfort.  Through this work, we now know that we ignore their alarm, health and future, at our collective peril and that of all beings around us.

Research by Lareef Zubair, Ruchira Lokuhetti, Janan Vishvanathan, Tuan Hadgie, Piushani Ellegala, Banuka Wijerathne and Chayana Gunatillake from the Foundation for Environment, Climate and Technology presented at the American Geophysical Union in December 2018.  We thank the villagers of Norochcholai, Dilmah Conservation and the US Embassy.  You can follow our work at www.climate.lk


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