The Pennon Group's two main subsidiaries are South West Water Limited and Viridor Waste Limited. The former holds the water and sewerage appointments for Devon, Cornwall and parts of Dorset and Somerset. Viridor Waste Limited is one of the largest waste management businesses in the UK, providing a full range of waste management services including landfill, recycling, incineration, wet and dry waste collection, site restoration and landfill gas power generation.

Pennon Group employs around 2,600 people within South West Water and Viridor Waste, (the majority of whom are also based in the region) making it one of the largest employers in the South West and therefore important to the regional economy.

The Pennon Group Plc web site provides an update on its share price every 15 minutes and throughout the trading day, publishes its results on-line and has a section of information for shareholders. Its Media Centre features regular press releases, facts and figures about the Group, maintains a picture bank for downloading and provides biographies of directors

It also produces an on-line version of its Annual Report and Accounts and its annual environmental report.