An easy to use A to Z of some of the most commonly used terms used throughout the water industry.
E. coli (Escherichia coli)
A bacterium taken as an indicator of faecal contamination.
The study of interrelation between living organisms and their environment.
economic level of leakage (ELL)
The point where the environmental, economic and social cost of water saved by reducing leakage is equal to the cost of new resources used in managing leakage. The sustainable economic level of leakage (SELL) is based on the same concept, but takes more explicit account of social and environmental costs and benefits.
- general efficiency: the percentage rate at which companies might be expected to improve efficiency and reduce unit operating or capital costs over time, because of organisational improvements or technical progress.
catch up: the rate at which a relatively inefficient company might be expected to catch up with the most efficient company.
comparative efficiency: a system of comparisons of unit costs used by Ofwat to identify more and less efficient companies, using statistical techniques.
cost base: (see jargon section C).
The improvement in service to customers resulting, for example, from reducing the likelihood of sewer flooding, improving water pressure and improving security of supply.
environmental quality objective (EQO)
The description of water quality required to maintain an identified use of a body of water.
environmental quality standard (EQS)
The concentration of a parameter which must not be exceeded if the EQO is to be maintained or achieved.
The transitional area between freshwater and the proper marine area. The outer part of an estuary is limited by the straight line between the furthest seawater extent of the low water line on each side of the estuary.
The transitional area at the mouth of a river between fresh water and coastal waters.
The enrichment of water by nutrients, especially compounds of nitrogen and/or phosphorus, causing an accelerated growth of algae and higher forms of plant life to produce disturbance to the balance of organisms present in the water and to the quality of the water concerned.