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  2. Drain-waste-vent system - Wikipedia

    en.wikipedia.org/wiki/Drain-waste-vent_system

    A sewer pipe is normally at neutral air pressure compared to the surrounding atmosphere.When a column of waste water flows through a pipe, it compresses air ahead of it in the system, creating a positive pressure that must be released so it does not push back on the waste stream and downstream traps, slow drainage, and induce potential clogs.

  3. Geosmin - Wikipedia

    en.wikipedia.org/wiki/Geosmin

    Geosmin (/ dʒ i ˈ ɒ z m ɪ n / jee-OZ-min) is an irregular sesquiterpenoid with a distinct earthy or musty odor, which most people can easily smell. The geosmin odor detection threshold in humans is very low, ranging from 0.006 to 0.01 micrograms per liter in water. [1]

  4. Water testing - Wikipedia

    en.wikipedia.org/wiki/Water_testing

    The Drinking Water Inspectorate is a section of Department for Environment, Food and Rural Affairs set up to regulate the public water supply companies in England and Wales. [6] Water testing in England and Wales can be conducted at the environmental health office at the local authority. [7] See Drinking Water Inspectorate.

  5. Soil moisture sensor - Wikipedia

    en.wikipedia.org/wiki/Soil_moisture_sensor

    A simple soil moisture sensor for gardeners. Soil moisture sensors measure the volumetric water content in soil. [1] Since the direct gravimetric measurement of free soil moisture requires removing, drying, and weighing of a sample, soil moisture sensors measure the volumetric water content indirectly by using some other property of the soil, such as electrical resistance, dielectric constant ...

  6. Soil contamination - Wikipedia

    en.wikipedia.org/wiki/Soil_contamination

    Soil contamination, soil pollution, or land pollution as a part of land degradation is caused by the presence of xenobiotic (human-made) chemicals or other alteration in the natural soil environment. It is typically caused by industrial activity, agricultural chemicals or improper disposal of waste .

  7. Water purification - Wikipedia

    en.wikipedia.org/wiki/Water_purification

    Groundwater: The water emerging from some deep ground water may have fallen as rain many tens, hundreds, or thousands of years ago. Soil and rock layers naturally filter the ground water to a high degree of clarity and often, it does not require additional treatment besides adding chlorine or chloramines as secondary disinfectants.

  8. Percolation test - Wikipedia

    en.wikipedia.org/wiki/Percolation_test

    A percolation test consists of digging one or more holes in the soil of the proposed leach field to a specified depth, presoaking the holes by maintaining a high water level in the holes, then running the test by filling the holes to a specific level and timing the drop of the water level as the water percolates into the surrounding soil.

  9. Acid sulfate soil - Wikipedia

    en.wikipedia.org/wiki/Acid_sulfate_soil

    The national sampling and identification manual provides: background information on acid sulfate soil formation and disturbance processes and environmental impacts; the minimum requirements of a desktop assessment and site inspection; and a guide to sampling and field testing. Key features of the national laboratory methods manual are: