Proposal:Treatment basins
| Treatment basins | |
|---|---|
| Proposal status: | Draft (under way) |
| Proposed by: | |
| Draft started: | 2021-02-23 |
Proposal
Water treatment is any process that improves the quality of water to make it appropriate for a specific end-use. The end use may be drinking, industrial water supply, irrigation, river flow maintenance, water recreation or many other uses, including being safely returned to the environment. This proposal adds detailed tagging for basins and related processing infrastructure found in water treatment facilities.
Proposed are the following new tags:
| Tag | Action | Description | Image |
|---|---|---|---|
| man_made=clarifier | Approve |  Clarifiers are settling tanks built with mechanical means for continuous removal of solids being deposited by sedimentation. A clarifier is generally used to remove solid particulates or suspended solids from liquid for clarification and/or thickening. Concentrated impurities (sludge) is discharged from the bottom of the tank, while the particles that float to the surface of the liquid (scum) are skimmed with mechanical arms. Clarifiers are easily identified by their visible skimming arms, and are often, but not always, round in shape.
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| man_made=water_filter | Approve | A filter tank removes particulate matter from water by forcing the water to pass through porous media. Common materials used for filtering include sand, gravel, or charcoal. Filter tanks for water treatment are usually located indoors, but some can be found outdoors also. | 
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| man_made=oxidation_ditch | Approve | An oxidation ditch oxidation ditch is a large round or oval ditch with one or more horizontal aerators typically called brush or disc aerators which drive the mixed liquor around the ditch and provide aeration. Unlike with aeration basins, there is no visible fountaining. (TODO: is this really different from aeration basins? Needs more thought)
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| basin=settling | Approve | A settling basin, settling pond or decant pond is an earthen or concrete structure using sedimentation to remove settleable matter and turbidity from wastewater. These differ from evaporation ponds (basin=evaporation) in that gravity, rather than evaporation, is used to separate the dissolved solids from water.
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| basin=aeration | Approve | An aerated lagoon is a simple wastewater treatment system consisting of a pond with artificial aeration to promote the biological oxidation of wastewaters.
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The following tagging is deprecated with replacement tagging as described below:
| Tag | Taginfo | Replacement |
|---|---|---|
| water=wastewater | One of the following: | |
| reservoir_type=sewage | ||
| man_made=wastewater_basin | ||
| man_made=sewage | ||
| reservoir_type=secondary_clarifier | man_made=clarifier |
Note: this proposal takes no position on whether basins should be tagged landuse=basin or natural=water + water=basin. For simplicity, this proposal will describe landuse=basin, however, either scheme may apply.
Rationale
Tagging
The appropriate treatment basin tagging is applied to an 
representing the geometry of the basin.
While some water treatment features (such as clarifiers or aerators) are easy to identify on imagery, others are more challenging without additional research into the purpose of the basins that surround treatment facilities. If the purpose of the basin cannot be determined, it is acceptable to tag it simply landuse=basin (or natural=water+water=basin) until the type of basin can later be determined.
The contents of a treatment basin can be tagged with the appropriate content=* tag.
Examples
Example: Drinking water treatment facility with reservoir, settling basins, and a small aeration pond.
Rendering
Features/Pages affected
External discussions
Comments
Please comment on the discussion page.