Case study: Wastewater reduction in Buenos Aires Refinery, Argentina

Buenos Aires is situated beside the Rio de la Plata in Argentina, and has a relatively abundant water supply. However, poor water management has meant that water has become artificially scarce. In the mid nineties, the Buenos Aires Refinery modified its treatment plants in accordance with a Shell Global Solutions Effluent Master Plan. In 1998 the local limit for hydrocarbons in water was significantly reduced from 30mg/l to 5mg/l and the Shell Group was also aiming to lower levels of hydrocarbons, driving the Shell Buenos Aires refinery to consider its own treatment facilities.

The refinery decided to build the second phase of the Water Master Plan, which aimed not only to improve effluent treatment, but also to cut wastewater by 40 per cent, so that less water would need treatment in the first place. The plan succeeded in minimising water usage and improving treatment beyond new discharge guidelines.

Construction for the second phase of water usage improvements was completed in 1999 and, since start-up, has been supported by a dedicated Water Team working to reduce hydrocarbon leaks at source. Results have been even better than expected. In 2000 the oil in effluent contribution was 0.49mg per litre of refinery effluent water, and this figure has continued to fall, reaching 0.054mg/l in 2003.

The reduction in wastewater has generated significant savings in capital investment and operational cost, and created a more environmentally sustainable operation. The current effluent level is lower than local legislative requirements and in line with Shell's Global environmental standards. This ability to meet environmental guidelines and continually improve performance is vital in maintaining a licence to operate, reducing legal liability and protecting the reputation of the Group.