Wastewater volume includes all manufacturing and site process wastewater as well as sanitary and food service wastewater.
Wastewater quality is measured by Chemical Oxygen Demand (COD) which is a measure of the oxygen required to chemically oxidise organic and inorganic compounds present in the water.
The COD is measured when wastewater leaves our sites, following any on-site treatment.
In 2002, we began to ask our sites to submit COD data following municipal treatment. This takes into account final treatment occurring at municipal or publicly-owned wastewater treatment works and therefore gives a better indication of the impact of our operations on the final receiving waterways. However, many of our sites have not submitted this data which means that the 2004 data still primarily reflects the COD after only onsite treatment. We will revisit this parameter and its scope as we develop our new EHS metrics and targets in 2005.