THE refinery’s water recycling project, a joint venture between Caltex and ImproChem currently under construction, will serve the purpose of extracting water from the Potsdam wastewater plant at a rate of 9.5 megalitres per day, piping this to Caltex and upgrading it utilising clarification, ultra-filtration and reverse osmosis. The water will then be used in the refinery’s boilers to create steam. This water has to be purified to near drinking quality to prevent fouling the boilers.

The construction phase of the project consists of a water plant at the Caltex Refinery and a pump station at Potsdam Water Works. The physical size/scale of the project is a maximum height of 8 m with a surface area of 2 500sq m. A pipeline to convey the Potsdam effluent has been laid between Potsdam and the Caltex refinery.

ImproChem will build, own and operate this facility, supplying Caltex with upgraded water over a period of twelve years.

This project would save 7 megalitres (200 000 kl/month) of potable water per day, ensuring that at least another 6 000 households are supplied with potable water in the water scarce Western Cape every month.

All chemical substances used in clarification or cleaning will be stored on site utilizing the ImproChem Portafeed system. This system includes a base tank for dosing with a returnable container for chemical supply. This minimizes chemical spillage and reduces handling of chemicals.

Commitment by ImproChem to safety health and environmental issues include the implementation of environmental management procedures for ongoing operations (an ISO 14001 Environmental Management System) at its factory in Umbogintwini which has been assessed and found to satisfy the requirements for SABS ISO 14001. This procedure will also be implemented during the operation of this plant.

ImproChem (Pty) Ltd has committed itself to the Responsible Care Guiding Principles in which Caltex conducts its operations in a manner that minimizes adverse environmental impacts and protects the health and safety of its employees and the public. The company promotes the principle of sustainable development in the conduct of Caltex’s operations and strives for continuous improvement in health, safety and environmental performance.

The emissions include the following:

• Waste from dissolved air flotation and backwash from filtration. • Reverse osmosis reject.

The waste from the dissolved air flotation and filtration will be accepted into the sewer by the City of Cape Town and will ultimately be fed into the front end of Potsdam Waste Water Works.

The reverse osmosis reject effluent will be discharged into the Caltex effluent plant. This effluent is ultimately pumped via the present pipeline out to sea. The pollution impact of this practise is minimal, as the salinity of this reject is ten times lower than that of the sea water salinity. Also, no undesirable reaction products are expected with the mix of Caltex effluent and the reverse osmosis reject, the company says. Other chemistries such as nitrogen and phosphorous, which would normally have an impact on the environment, will be incorporated in the dissolved air flotation waste and returned to Potsdam Water Works for removal.

Abstraction of the sewage effluent on Potsdam has undergone an EIA protocol check list by the City of Cape Town and it was agreed that the portion of the project that falls within the Potsdam treatment works boundary is a Category 2 project and hence an EIA is not required.