• Numaligarh Refinery Limited (NRL), which has received several oil industry environmental awards, interns its refinery waste in a hazardous waste landfill near Kaziranga National Park and Brahmaputra River. The park is a unique UNESCO World Heritage Site.
  • By contrast to Assam's other refineries, NRL does not deliver its waste to hazardous waste treatment facilities, as required by Indian law.
  • As the old landfill is filling up, NRL plans to open a new one. After the extension of the oil refinery's production, the amount of hazardous waste will triple.
  • NRL is Chempolis's partner in India's Assam. Waste from the bioethanol refinery to be build as a joint venture will be disposed in the new secure landfill.

At various stages of oil refining, various types of waste is being produced in addition to petroleum products. These include biological and chemical wastes and oily sludge. Wastes contain, for example, various hydrocarbons and phenol. Dangerous for humans and the environment are also various heavy metals such as chromium, copper, cadmium, lead, manganese, and nickel. The chemical sludge of the refining process is strongly alkaline and thus corrosive. Biological waste is rich in nitrogen, phosphorus and potassium. The oily sludge, on the other hand, contains a large variety of greases and oils. When discharged, these release the greenhouse gases into the atmosphere.

Crude oils from different parts of the world differ in composition, which also affects the composition of the hazardous wastes generated in the refining processes. Numaligarh refinery uses Assamese crude oil for about 3 million tonnes per year. It will leave about 1400 tonnes of waste sludge, which contain for example, 126-140 kg of phenol, 80-100 kg of nickel, 100-190 kg of chromium, 640-840 kg of zinc, 190-340 kg of manganese, 390-550 kg of copper and 56-75 kg of lead. By contrast to other crude oil blends Assamese crude oil contains a lot of wax. About 7% of the volume of crude oil used is wax. The figures are based on a report about the solid waste management at Numaligarh oil refinery, which NRL ordered in the early 2000's.

At the Numaligarh refinery, the waste sludge is dewatered with a centrifuge leaving solid hazardous waste of about 750 tonnes per year.

At the Numaligarh refinery, the waste sludge is dewatered with a centrifuge leaving solid hazardous waste of about 750 tonnes per year. From several alternative options for the disposal of hazardous wastes, the refinery chose the interment into a secure landfill. This was also recommended by the consultant and accepted by the environmental authorities. In the survey, the consultant proposed the implementation of a secure landfill by isolating dry waste from the air and water between the clay layers and sealing films. Also a runoff system for preventing groundwater contamination and exhaust pipes to remove the fire hazard from gassing caused by decomposing were included in the plan. Above the waste buried, a humus layer would be planted with vegetation.

The secure landfill of hazardous waste near the Kaziranga National Park

Even during the consultant research phase on the different alternatives of disposal of hazardous wastes, NRL had taken a decision on the location of the secure landfill, which is also mentioned in the consultant's report (26°37'30 "N 93°43'30" E). The company built the secure landfill between Deopahar Forest, a proposed reserve forest and Dhansiri River. The distance from the Kaziranga National Park is about ten kilometers, the Dhansiri riverside about half a mile. The latter river is the Brahmaputra tributary flowing through the UNESCO World Heritage Site, Kaziranga National Park. Within a few miles downstream are the floodplains that regularly go under water during the monsoon season and maintain a unique ecosystem. Right next to landfill there are settlements and a hospital. The nearby villages are inhabited by tens of thousands of people.

The secure landfill site according to the report of consultant.

The landfill of hazardous waste is located on the Kaziranga National Park's protective zone, "No-development Zone", which was set up by the Indian government to protect a delicate natural environment and safeguard the wildlife corridores. It was also to ensure that there will be no other industries besides the oil refinery in the region, including construction, extension of oil refinery or production of new products without prior decision by the Indian central government.

According to the law on hazardous waste management in India 2008, the waste producer must ensure their recycling, either in their own incineration plant or by purchasing a recycling service from a licensed waste disposal plant. An exemption to the recycling of waste can be applied for from the environmental authorities of the state, if there is licensed no hazardous waste treatment facility in the state.

NRL has not become a customer of such a facility, although the problem has been repeatedly discussed during environmental clearance processes for refinery expansion projects. Other Assam oil refineries handle their own hazardous waste through specialized companies. At the same time, the Pollution Control Board of Assam have granted permission to place NRL's hazardous waste at a secure landfill until 2021. NRL circumvents the law by claiming that hazardous waste disposal businesses are not available in Assam. The state's environmental authorities, in turn, violate the law by granting an exemption.

Pollution measurements from suitable locations at a convenient time

In a clarification given by NRL for the 2015 environmental clearance application shows that the company does not comply with the consultant's original instructions on the technical implementation of the secure landfill. The humus layer on the top of the hazardous waste is only half of the thickness suggested by the consultant. The document also contains no mention of insulating clay or sealing film layers. If the insulating film and the clay layers are missing, the water collection will not work and the rainwater will run out through hazardous waste to groundwater and nearby waters.

If starting with the consultant's figures, there are tons of tons of phenol and various heavy metals buried in the site.

The environmental clearance applications made at different times show that the levels of harmful substances have not been measured in watercourses or groundwater below the secure landfill of hazardous waste. Measurements for the applications have also been made in the late autumn and early months when Assam is very dry and the water discharge is small.

The NRL's secure landfill of hazardous waste is about to become full. It has been in operation since the year 2004. It is difficult to estimate the amount of hazardous waste disposed of in to the landfill because the production volume of refinery has varied from one year to the next due to problems with the supply of crude oil. If starting with the consultant's figures, there are tons of tons of phenol and various heavy metals buried in the site.

NRL has also buried wax contained in crude oil into the landfill up to 2016. When in an airless space, high calorific waxes produce plenty of methane, a greenhouse gas that is more dangerous than carbon dioxide. During 2016 a new plant was inaugurated at the refinery, which separates the wax as a raw material for industrial use. The NRL has reported that emissions from the decommissioning landfill are monitored through two wells and regular groundwater samples. No other plans for the wastes interned in the landfill exists.

New landfill for triple waste

NRL has been preparing a new landfill site for hazardous waste. There is a plan from a consultant. The oil refinery wants to dispose 6,000 cubic meters of solid waste in a new secured landfill in the coming years. The company does not intend to recycle its refinery sledges through hazardous waste treatment plants.

The new dimension is brought by the refinery expansion plans. NRL's objective is to triple its production capacity over the next few years. It requires crude oil to be imported elsewhere, because Assam's own oil fields can't supply enough to increase production. The refinery plans to build a crude oil pipeline from Bangladesh, where a terminal would be made for imported crude oil from other parts of the world. The oil refinery at Numaligarh would then start to export oil products like diesel oil and petrol in a large-scale for example to Myanmar and Bangladesh. The tripling of production means three-fold more hazardous wastes.

Also, the waste from the bio ethanol refinary planned jointly by NRL and Chempolis Oy will be placed in the same landfill. How much waste there is going to be, depends on the combination of the ethanol refinery, that is being built. If a power plant is built in connection with the refinery to produce electricity and heat into the process of ethanol production, there is little waste left, as distillation residues and the carbon produced by the process can be burned in a power plant. If a power plant is not built, the company places ethanol distillation waste into a secure landfill. Processed coal is sold on the market. As a result of the latter solution, the environmental benefits of the refinery promised by Chempolis Oy will disappear as distillation sludge into the landfill and as carbon dioxide into the atmosphere. At present, it seems that the project is being implemented without a power plant.

NRL's blemished reputation

While Numaligarh Refinery Ltd has received oil industry environmental award, its reputation has been bothered by environmental scandals in recent years. In August 2016, the National Green Tribunal (NGT) issued a ruling that the refinery had to dismantle the walls built in the Kaziranga National Park's protection area, the No-Development Zone and restore the area's forest. Later, it has become apparent that both the NRL and Chempolis Oy, a joint venture, will be located in the protected area for which the construction is prohibited.

Local communities accuse the petrochemical plant's emissions on the fish deaths in the rivers of the region and making the fish inedible.

The latest scandal is directed at Brahmaputra Cracker and Polymer Ltd (BCPL), a partly-owned subsidiary of NRL. The factory is located in the upper reach of the Brahmaputra stream in Dibrugarh Lepetka. NRL supplies the naphta required for the polymer production of the plant. The National Green Tribunal forced the company to drive its production down in September. The reason was that the emissions of harmful substances to Brahmapurtra and its tributaries exceeded the emission limits. Local communities accuse the petrochemical plant's emissions on the fish deaths in the rivers of the region and making the fish inedible. Residents in the neighboring areas are also concerned about air pollution allegedly causing skin and respiratory diseases in nearby villages. They require impartial research. Appeals handling at the National Green Tribunal is pending. The factory is still standing.

JUha Holma