Acid waterlevels in Weliweriya region: Knee-jerk reactions in closing a cutting edge-factory

Mevan Pierisin The Island, 11 August 2011
I have read with great concern and sorrow, the reports that have appeared in the news papers regarding the events that have led to the temporary closure of Dipped Products Plc factory at Weliweriya. This organization began as a joint venture between Hayleys Ltd and Richard Pieris & Co Ltd in the mid-1970s at Kottawa, to add value to raw rubber at a time when the latex based glove making industry of our country was in its infancy. The venture began to produce gloves for the export market without any foreign technologists assisting, and has since then, grown to be the world’s fifth largest producer of household & industrial rubber gloves, in the world. During this journey, Dipped Products Plc (DPL ) has expanded operations to Weliweriya and Hanwella, generating employment to many Sri Lankans and has made a major contribution towards earning a good image for Sri Lanka in the global market, as a centre of excellence in rubber glove production. DPL has even been able to set up factories in other parts of the world and can be considered to be one of the best examples of how Sri Lankans can by their own capabilities, with little or no assistance from foreigners, become a global giant. Needless to say, during this period DPL has taken enormous care not to damage the external environment. A very high standard of social responsibility has been displayed by this organization. I have very recently supervised an undergraduate research project of the waste water disposal system at DPL and write this article with first hand knowledge of DPL practices, in the fervent hope that it would contribute towards solving the prevailing problem of national importance.
map of acidity levelsAn article dated 4 August 2013 written by my good friend, Professor O.A. Illeperuma, titled, “ How well water in Weliweriya area is getting excessively acidic due to leakage of acid from a far off factory”, appears in the internet, and such headlines only serve to mislead the public more, and add to the confusion. I am at a loss to understand how Oliver has come to the conclusion that there is a factory leaking acid as he has not named the factory nor elaborated on it in the article. I am sharing my knowledge of the inside happenings of DPL on the basis of forty years of experience in rubber product manufacture in other organizations, so that people in the area of Weliweriya, politicians, scientists and the public in general, would be able to understand  the situation more meaningfully.
The recent uprising of the people living in the area of the DPL factory at Weliweriya is related to their well water being acidic at a level far below the accepted norm of acidity levels of drinking water. An excellent, comprehensive study of the acidity levels of well water, of the entire Attanagallu oya basi, carried out by R S Wijesekere and C Kudahetty of the Water Resources Board, is available for study as part of the proceedings of the workshop on challenges in ground water management in Sri Lanka, 2011. The map on pH variation of this basin presented by these two authors is very revealing. pH is an index which measures the acidity level and a value of less than 7 indicates acidity and lower the value greater the acidity. Weliweriya belongs to this geographical basin of 727 square kilometers, and is a very small area located at the very southern border of the basin centrally placed on the southern border. It is clearly seen from the map, that, most of the area in the entire basin is acidic, and the entire central region of this wide basin, running all the way from the southern border to the northern border is more acidic than the two sides. The authors have concluded by saying “ pH values of shallow groundwater in the basin show uneven distribution throughout the basin.”  Their study reveals pockets of extreme acidity to exist scattered,  and even pockets of extreme acidity ( ph 4 – 5 ) and alkalinity ( pH 7 – 8.5 ) are seen to exist adjacent to each other as next of neighbours at an equal distance from the DPL factory. They have also concluded that the well water is acidic in many localities including Minuwangoda, Weediyawatta, Gampaha and Weliwerya. This study clearly shows that the high acidity in well water is not a characteristic of water at Weliweriya alone, but that of the large Attanagalu basin in varying degrees. Therefore, the problem prevailing at Weliweriya has to be evaluated not in isolation but in the context of its geographical setting.
A latex based product manufacturing factory is very different to a latex based dry raw rubber manufacturing factory, in the character of the latex used. In a dry raw rubber factory the latex used is the plantation field latex, which is a dilute latex having a slightly acidic pH of about 6.5 and formic acid is used to coagulate the latex, whereas DPL, which is a product manufacturer is using  processed concentrated latex, which is made highly alkaline ( around pH 10 ) to maintain its stability. It is absolutely essential that the alkalinity of the latex and that of its mixes be preserved until the rubber in the latex is gelled or coagulated to form the products. In the dipped glove manufacturing process practiced by DPL, the gelling is done by the use of environmentally friendly divalent calcium ions and not with acids, although it could be done using acids as well. Therefore, what the people of Weliweriya and everyone else must know is that, at the DPL factory at Weliweriya, acid is not used to gel or coagulate the latex and that the process operates with alkaline mixes of latex and not acid mixes. The only acid that is used in the factory is a small amount to clean the ceramic formers of any contaminations. This water is neutralized by the factory before being released to the waste water treatment plant.
There is one other step in the manufacture of dipped gloves that could generate acid. Since, the gloves are based on natural rubber they have a high degree of tackiness. Therefore, the standard method adopted is to treat the manufactured gloves with dilute chlorine water, to make them smooth. After use, the chlorine content in the waste water is eliminated by a chemical treatment that renders the waste water from this operation alkaline.
Quite apart from what has been stated above, what is of greater importance is the quality of the water released to the environment by the glove factory, more than the operational dynamics within the factory, which have been spelt out in this article merely for greater understanding of the reality which prevails within a latex based dipped glove factory.
In the recent research study I supervised, based on measurements taken over several months, the waste water disposed to the environment was found to be alkaline and close to pH 8, which is well within the standards for waster water effluent release and as such the water released is certainly not acidic. This would mean that in relation to hydrogen ion content which causes acidity, the factory has a very clean sheet. Further, at Weliweriya, the waste water after treatment is released to the middle of a fairly large adjacent coconut plantation owned by the factory so that the coconut trees would assist to purify the water to an even greater extent.
There are also other relevant factors to consider in respect of acidity in the wells around Weliweriya and in the greater part of the Attanagalu oya basin. It has been reported that, below a certain pH level, trivalent metal ions of aluminium have the capacity to convert water molecules to hydrogen ions that generate acidity. The aluminium is present in all types of soils. The contribution of aluminium becomes highly significant in acid soils, and the Weliweriya soil is one such soil. Between the acid range of pH 4 and 6, the AL3+ trivalent ion can progressively extract the OH- radical from water to generate 3 H+ ions per aluminium ion. It is also believed that that the presence of ferrous/ ferric ions in the soil can also contribute towards acidity. Fertilizers can also generate acidity. Obviously, there are other factors as well, and one such factor is decomposition of organic matter. The research findings of the project supervised by me indicates that the waste water treatment plants installed at both Weliweriya and Kottawa are highly effective in removing the oxidizable organic matter in waste water and the water released to the environment is well within the tolerance limits stipulated by the standards for chemical and biological oxygen demands.
Detailed atomic absorption studies were also carried out to estimate the metal ions in waste water discharged by the glove factory. The only metal ions of any significant quantity were sodium, potassium and calcium ions. No dangerous metal ions were released to the environment.
The people of Weliweriya have good reason to be disturbed by the acidity levels of their well water; so also people of other areas having a similar problem. Results of research studies already done on well water of this region suggests that, the prevailing low acidity is not an outcome of acidic materials released from a single production factory, but due to a basket of factors covering a wide area of a geographical basin.We need to recognize the problem faced by the people of Weliweriya and other areas with due respect, and it is indeed a problem which needs attention. I believe that a solution has to be found by way of an investment by the State to provide pipe borne drinking water to people of this area. This article is written in order to enlighten the people of the greater area of Weliweriya that a solution to their problem does not exist in closing down a factory that is not releasing acidic waste water. Such an exercise would be like killing the goose that lays the golden egg.
It is a great pity that the production factory is right now not in operation. It must start as soon as possible, as otherwise the international markets will lose faith in DPL, which has so far made an immeasurable contribution to the growth of the rubber product manufacturing industry, purely by native enterprise. It has to be understood by all that, Rome was not built in a day. DPL is the creation of a long period of hard work and strategic planning to be a global giant and can not be allowed to decay in this way. I am certain, that the patriotic citizens of Weliweriya will cooperate to permit DPL to resume operations if the people are informed of the true facts of the situation. This article is a small contribution made with that intent, by one who has been involved in rubber product manufacture for more than 40 years in three of Sri Lanka’s biggest multi-product factories. It is my considered view that the Dipped Products factory which is releasing treated alkaline water, with minimum organic matter and harmless metal ions, in no way is responsible for the wide spread well water acidity now prevailing in the Attanagalu Oya basin. It is also relevant to note that DPL, being very conscious about sustainable development, is not incinerating or dumping any damaged defective gloves and instead is exporting the waste gloves as well. I sincerely hope that government will move effectively to implement a pipe borne drinking water supply to the acidic zones of the Attanagalu oya basin, as there may not be another method by which the problems the people of these areas are facing can be solved permanently.
MEVAN PIERIS: MSc, MBA, FPRI ( UK ), FIChem, C.Chem.  and Former President Plastics and Rubber Institute & Institute of Chemistry Ceylon
wWALIWERIYA pic A scene at Weliweriya after the recent riots and security force actions