Sabiñánigo is a municipality of long industrial tradition. Between 1975 and 1988 a pesticide plant settled in the area produced LINDANE over almost 20 years.
According to data provided by the CNRCOP, “Inquinosa” produced around 900 tons of Lindane per year. Each ton produced another 8 extra tons of non-commercial isomers. Therefore, the plant activity was responsible for the production of around 7.200 tons of waste per year.
In total, around 100.000 tons of toxic and hazardous waste were buried without any safety or control in different landfills.
The presence of liquid waste and the contact along many years of solid waste with surface water and groundwater are responsible for the notorious impact on the environment. To date, the liquid waste has filtered through the subsoil polluting the bedrock and the underlying aquifer, and has contaminated soil, water and aquifers resulting in the environmental degradation of the area.
The pollutant of the subsoil of Bailin’s landfill mainly consists of a mixture of different HCH isomers (Lindane and other HCH compounds not commercialised during the manufacturing period), by-products of the manufacturing process (Benzene, Chlorobenzenes…) and intermediates of the degradation process belonging to those families of organochlorines (Chloro-cyclohexen, chloro-phenols etc.). Compounds exist in subsoil as free phase not miscible with water or Dense Non-Aqueous Phase Liquid (DNAPL), migrated significantly in depth due to their rather higher density to water. That organic phase includes volatile organic compounds (VOC) and semi volatile organic compounds (SVOC), both soluble in water, and is responsible for the generation of dissolved-phase plumes of contamination for both compound families.
The type of pollutant buried in the Bailin landfill consists of a mixture of HCH isomers and other chemical compounds from failure reactions in the Lindane production. They exist in the subsoil as a multicomponent dense non-aqueous phase liquids or DNAPL, creating, in contact with groundwater, a pollution plume including a wide range of organochlorinated compounds.
We have identified 5 out of the 12 pollutants listed in the Regulation (CE) No 850/2004 and included in the Stockholm Convention as source for adverse effects in human beings and ecosystems - hexachlorobenzene (HCB), alpha hexachlorocyclohexane (α-HCH), beta hexachlorocyclohexane (β-HCH), Lindane y pentachlorobenzene-.
The shifting of DNAPL in the aquifer is controlled by gravity and its high density. The affection spreads from the source to the Gállego River more than 800m, at a depth of between 20-40 m reaching the river, a drinking water supply. It presents diffusion phenomena from water to rock matrix and vice versa, from the rock matrix to groundwater. This diffusive exchange can lead to maintain significant residual concentrations in the groundwater contained in the fractures of the aquifer.
The pollution trapped in the bedrock and the elevated concentrations well above the normative values for groundwater and soil represent themselves a high risk to health and environment.
Notably health risks have been reported: effects on the nervous, cardiovascular and musculoskeletal systems. Chronic exposure has been associated to adverse effects on the liver, blood and the immune system. Moreover, it has shown carcinogenic activity and reproductive and developmental system.
The pollution plume spreads from the landfill (source of contamination) to the Gallego River, more than 800 metres and at a depth of 20-40 metres reaching the river, a drinking water supply. The DISCOVERED LIFE pilot test scope extends to a small area, but its expected results may be extrapolated to surrounding areas with the same pollution problems. Within an area of 2 km2 from the landfill there are two more sites including a second HCH landfill and the Inquinosa factory itself.
The composition of the Bailín residue analysed is coherent with the waste generated by the lindane production processes. Therefore, contaminants spectrum identified in Bailin should be similar to the ones produced in other lindane manufacturing sites.