Glossary B

The Environmental Glossary. Letter B +++ 'Soil', 'Bloc', 'Back Pressure'
A Back Pressure is a pressure that can cause water to Backflow into the water supply when a user's waste water system is at a higher pressure than the public system.

A Backflow /Back Siphonage is a reverse flow condition created by a difference in water pressures that causes water to flow back into the distribution pipes of a drinking water supply

Backflow is a reverse flow in water pipes.

- Background: A background (radiation) is Natural radiation caused by sun exposure, cosmic rays from space, and radioactive elements found in the earth's crust.

A Background concentrations: is In this context, EPA uses background concentrations to mean the contributions to outdoor Air Toxics concentrations resulting from natural sources, persistence in the environment of past years' emissions and long-range transport from distant sources.

A Background count rate is the counting rate obtained on a given instrument with a background counting sample. Typical reference background counting samples are:

Background extinction is the normal extinction of various species as a result of changes in local Environmental conditions. Compare mass depletion, mass extinction.

A Background Level is
1. The Concentration of a substance in an Environmental media (air, water, or soil) that occurs naturally or is not the result of human activities.
2. In

The Background radiation is the radiation arising from radioactive material other than that under consideration.

A Backgrounding is Growing program for Feeder cattle from the time calves are weaned until they are on a finishing ration in the feedlot.