What’s making the water in Shillong oily and undrinkable?

Authorities say it is because of the high usage of chemicals needed to treat the turbid waters in the once pure rivers and springs of the region. But what is polluting the water in the first place?

Meghalaya has always prided itself on its pure water flowing from the crystal clear mountain streams and springs amidst pristine forests. But over the past three years, the state’s Public Health Engineering (PHE) department has been receiving numerous complaints about the poor quality of the water being supplied to homes. A Public Interest Litigation (PIL) and an “Own Motion” by the Meghalaya High Court (MHC), point to the urgency of the matter.

The problem is that rivers are being polluted by unchecked sand mining, quarrying, rapid urbanization and other “developmental’ activities in the ecologically sensitive regions of this hilly state, causing a deterioration in water quality, as admitted by the Meghalaya State Assembly Committee on Environment. The resultant high turbidity due to heavy presence of soil and other particles in the once pure rivers and springs means more chemicals have to be used to make the water fit for drinking.

Where does the city get its water?

PHE has several schemes supplying drinking water to the 3,54,759 people (2011 Census) in the Shillong Urban Agglomeration area. The main one which feeds more than half the capital’s population is the Greater Shillong Water Supply Scheme (GSWSS), which sources its water from the Umiew river at Mawphlang, about 25 kms from the city where the water treatment plant and reservoir are located.  The Shillong Municipal Board (SMB) which serves the Shillong Municipal Area alone also has its own network and water sources but since the last few years has been sharing water from the GSWSS to feed its clients as its water sources are drying up. 

SMB’s water sources, seven springs and a stream, Umjasai, all lie in the Shillong Peak Protected Forests Range.  But deforestation has devastated these sources of water, say SMB officials. The SMB is making efforts to rejuvenate its water sources with the help of the state forest department, but with little success so far.

The Meghalaya Legislative Assembly Committee on Environment led by the SMB’s chairman, S K Sun, MLA, which had inspected the reservoirs and treatment plants at Mawphlang on June 25th found that the city has a major problem — of both water quality and quantity. The panel, with six MLAs as members, was set up by a resolution of the Meghalaya Legislative Assembly last year to go into growing issues of environmental degradation. 

What’s wrong with the water?

Officials at the Mawphlang water treatment plant told the visiting panel that when water turbidity increases, especially now during the rainy season, higher quantity of chemicals like aluminium sulphate and hydrated lime needed to be used to regulate the pH level of water and ensure efficient filtration. Alum works as a coagulant which binds all the suspended particles in raw water into lumps that is easily removed by filtration and settling. Hydrated Lime adjusts the pH level. 

Inspection of the Mawphlang Greater Shillong Water Supply Scheme water treatment plant on June 25, 2019. In the picture, Chief Engineer K D Talukdar (extreme right) explains the functions of the clariflocculator to Members of the Meghalaya Assembly Committee on Environment.

As per submissions to the High Court last November by the Meghalaya Pollution Control Board, which is a part of the expert panel constituted by the chief engineer of the PHE, the high alum content in the water sometimes ends up making the water oily. The PHE and other water authorities of the state including the SMB and the Meghalaya State Pollution Control Board were dragged to court in the wake of the clamour raised by the Khasi National Awakening Movement (KHNAM) and other organisations about oily and contaminated water coming out of the PHE taps. KHNAM is a political party which presently has one legislator in the state assembly. 

Other organisations which have raised concerns at various times about water quality are the State Development Reforms Commission (SDRC), Societal Action against Human Trafficking, Drug Abuse and Social Problem (SAAHAT-DAASP), Civil Society Women’s Organisation (CSWO), All Meghalaya Industrial Workers’ Union, and the North Shillong Domestic and Unorganised Workers’ Union. These organisations have jointly sought a CBI inquiry to look into their allegations of rampant corruption in the department which, they say, led to the state’s water woes.

Getting to the root of the problem

Meanwhile, S K Sun, who was earlier chief engineer of PHE before he was elected to the Assembly in 2018, said unless the catchment areas consisting of about 115 sq km is protected, the GSWSS project on which the capital depends for its drinking water is in danger of becoming redundant. Sun told us that he would recommend to the State Government that the area be declared a protected zone under the National Wetlands Policy, as there was no other way to make people understand the importance of conserving the catchment areas and providing alternative livelihoods to the people now dependent on sand mining and stone quarrying.

According to official sources in the office of the Divisional Forest Officer, East Khasi Hills, there are more than 100 quarries in the district and about a dozen in the said catchment area.  The forest department, along with the Mining and Geology department, regulate these activities and hold responsibility for enforcing the Meghalaya Minor Minerals Concession Rules, 2016. Under these rules, all sand or stone miners need to take permission from the forest department before mining permit is allotted. At present, all the quarries have been shut down as part of the forest department’s efforts to better regulate quarrying activity. The State Government levies a royalty on minor minerals generated from quarrying, earning Rs 8,10,77,823 from this in 2017-18.

But this is of little comfort to consumers who are concerned about the possible adverse health effects of higher doses of alum in the water. One member of the Sun Panel, H M Shangpliang, MLA, asked the PHE if there was any other water purification technology they could use instead of alum. But the only alternative PHE could offer was to use a substitute anti-coagulant chemical known as Poly aluminium chloride. 

Chief engineer of PHE, K. D. Talukdar, when asked about the poor quality of water said while earlier the treatment plant had only one clariflocculator, it now has two to handle the muddy water during the monsoon season and ensures that only the right dose of alum is used. “The alum itself is filtrated out of the water,” said Talukdar. But the long-term solution, he admits, would be getting raw water that is less turbid, which does not look possible in the near or far future.


  1. Paul E says:

    The clean water needs a clean source.. it’s high time we take initiative to clean the river..
    However, PHE have done gr8 job this year.. we are getting very less oily water compared to the past

    • Badap Warjri says:

      You are getting less oily water? Please tell us where you live so we can all join you because here in Shillong the water is still VERY oily. Apart from the oil, do we even know what other contaminants it contains? Yes PHE has done a great job- FOR THEIR POCKETS!

  2. Thelma Lobo says:

    Advanced Research should be promoted on an urgent priority basis!
    UNESCO can step in, if helpless.

  3. Badap Warjri says:

    Does Mr Talukdar think all will be made ok by claiming that “safe amounts” of aluminium sulphate is being used and that it is completely filtered ? Citizens are not all fools. Dear citizens who are unknowingly being poisoned because Rs 8,10,77,823 was greedily pocketed by the state govt as mentioned in the post, at the expense of our source of drinking water(the very essence of our lives), here is what you should know about Aluminium Sulphate:
    – Irritant to the skin and eyes.
    Minor ingestions (dilute solutions):
    – Burning in the mouth and throat, mild gastrointestinal upset.
    Substantial ingestions:
    – Nausea, vomiting, diarrhoea, abdominal pain, rarely
    haemorrhagic gastritis, circulatory collapse and multi-organ
    – Increased aluminium absorption and retention in bone is
    reported following acute ingestion without apparent adverse
    – Chronic exposure to aluminium sulphate in drinking water may
    be involved in the pathogenesis of Alzheimer’s disease
    though this remains a highly contentious issue.


    – Potential pulmonary irritant
    Injection- Aluminium sulphate used in water purification is a source of
    aluminium toxicity in haemodialysis patients and may cause
    “dialysis dementia”. Aluminium toxicity in these
    circumstances may contribute also to renal osteodystrophy
    and a microcytic anaemia.

  4. Paul E says:

    I was comparing to water that is 1 or 2 years back is very much less oily..
    Who pollute the water, its you and I who pollute.. if we as a citizen’s with the government together cares for our health we should clean the source of drinking water.
    We can’t expect to get a very clean water from the drainage just like that.if you don’t agree with that then what more!!!

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