An easy to use A to Z of some of the most commonly used terms used throughout the water industry.
Areas designated under EC directive 76/160/EEC. Number of bathers is main criterion.
biochemical oxygen demand (BOD)
The quantity of dissolved oxygen in water (mg/l) consumed under test conditions during a given period (5 days) through the microbiological oxidation of biodegradable organic matter present in wastewaters. One of the standard tests used to characterise effluent quality.
Ability of substance to decompose without adding chemicals.
A process in which settled sewage uniformly trickles downward through a bed of inert material such as slag, moulded plastics or clinker, thus permitting contact with the biological film with which the surfaces of the medium are coated so that oxidation and clarification take place.
biosolids (sewage sludge)
Produced from the treatment of sewage. Biosolids have to comply with EC and UK legal standards and the Safe Sludge Matrix for agricultural use.
blue flag beaches
Beaches which meet a number of detailed criteria for cleanliness and facilities including compliance with the EC directive's guideline bathing water standards.