Glossary
These explanations are designed to help understanding of the non-financial KPIs featured in our performance summary. LINK
Environment
Pollution incidents: the number of category 1 and 2 incidents (i.e. the most serious types) that cause pollution of water courses during the calendar year, as defined by the Environment Agency. For further explanation please visit http://www.environment-agency.gov.uk .
Water quality: mean zonal compliance is a calendar year measure of overall drinking water quality used by the Drinking Water Inspectorate. It comprises an average measure of 40 different parameters tested at customers’ taps and supply points. For further explanation please visit www.dwi.gov.uk .
Greenhouse gas emissions: these are measured in metric tonnes of carbon dioxide equivalent. This is derived by multiplying the amount of the gas emitted by its global warming potential (i.e. how much more effect it has compared to carbon dioxide). Greenhouse gases are six gases that we measure for their contribution to global warming. Each gas has a different impact and these are expressed in terms of carbon dioxide emissions. For further explanation please visit www.defra.gov.uk .
Renewable energy generated: the number of gigawatt-hours of energy generated by United Utilities from renewable energy sources such as hydro electric. A gigawatt is a unit of power equal to one billion (one thousand million) watts.
Employees
Employee engagement: employee opinion survey: we carry out an annual survey of our employees to find out what they think about working for United Utilities. This leads to action planning to make United Utilities a better place to work. The employee engagement measure encompasses how employees think, feel and act.
Health and safety: accident incident rate per 100,000 employees: this is the number of lost time accidents (business time lost due to accidents) in the year, pro-rated to produce a rate per 100,000 employees.
Customers
Water: relative efficiency: how efficient we are in spending money to run our services compared to other water companies, as assessed by regulator Ofwat for the calender years ended 31 December 2007 and 2006.
Wastewater: relative efficiency: as above.
Leakage: rolling annual average leakage: measured in Ml/d or megalitres per day. One megalitre equals one million litres.
Sewer flooding: number of properties on the at-risk register: a register that records properties at risk of experiencing one or two sewer flooding incidents in ten years.
Overall customer satisfaction - water (in response to enquiries): an internal assessment mechanism which measures the level of customer satisfaction in relation to the responses received from enquiries, which involves interviewing customers. Such sample interviews are conducted monthly.