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====Water Quality==== | ====Water Quality==== | ||
There are three criteria to having acceptable quality drinking water. | |||
*No fecal bacteria | |||
*No harmful chemicals | |||
*No bad taste or smell | |||
Rainwater catchment systems have commonly found contaminants due to the location and isolation of rooftops. | |||
{|class=wikitable | |||
|+Common contaminants of rainwater catchment systems<ref name=pacific/> | |||
!Contaminant | |||
!Source | |||
!Risk of entering Rain Tank | |||
|- | |||
|'''Dust and Ash'''||Surrounding dirt and vegetation <br/> Volcanic activity||''Moderate'':Can be minimized by regular roof and gutter maintenance and use of a first-flush device | |||
|- | |||
|'''Pathogenic Bacteria'''||Bird and other animal droppings on roof, attached to dust||''Moderate'':Bacteria may be attached to dust or in animal droppings falling on the roof. Can be minimized by use of a first-flush device and good roof and tank maintenance. | |||
|- | |||
|'''Heavy metals'''||Dust, particularly in urban and industrialized areas, roof materials||''Low'':Unless downwind of industrial activity such as a metal smelter and/or rainfall is very acidic (this may occur in volcanic islands) | |||
|- | |||
|'''Other inorganic<br/>Contaminants(e.g. salt from seaspray)'''|| Seaspray, certain industrial discharges to air, use of unsuitable tank and/or roof materials||''Low'':Unless very close to the ocean or downwind of large-scale industrial activity | |||
|- | |||
|'''Mosquito Larvae'''||Mosquitos laying eggs in guttering and/or tank||''Moderate'':If tank inlet is screened and there are no gaps, risks can be minimized. | |||
|} | |||
===Filtration=== | ===Filtration=== | ||
===Gutters, Pipes, and Downspouts=== | ===Gutters, Pipes, and Downspouts=== | ||
Revision as of 17:42, 14 June 2017
Literature Review
This page describes some of the basics behind designing Rainwater Catchment Systems. It is a collection of resources pulled from similar projects that are documented throughout Appropedia, and contains helpful resources for those interested in learning more. Please feel free to add even more helpful content!
Rainwater Catchment
A rainwater catchment system is a system that collects, filters, and stores rainwater for community or household use. [1]
Rainfall
One of the first steps to designing a Rainwater Catchment system is to determine the amount of rainfall that will fall in the desired location. A good practice is to determine the average precipitation depth in inches for each month. This data can typically be found from sources such as the PF Data Server from NOAHH.
Catchment Potential
Besides the amount of rainfall that is available to be collected, the size of the collection surface will determine how much of the available rainfall will be collected for usage. Sites such as the Rainwater Collection Calculator can aide the design process.
Roofing
The type of construction material is important for a rainwater catchment system. Depending on what material is used for the roof, the collected water can be contaminated by carcinogens[1]. The roofing materials used in a rainwater catchment system should be chemically inert to keep contaminants out of the system. In addition to the roof material itself, the climate can influence the contaminate runoff depending on the material.
Types of Roofing Material
The following are brief descriptions of a few common roofing materials and their benefits and drawbacks when being considered for Rainwater Catchment Projects.
Thatch: Filler
Wood: Filler
Tile: Filler
Concrete: Filler
Metal: Filler
Water Quality
There are three criteria to having acceptable quality drinking water.
- No fecal bacteria
- No harmful chemicals
- No bad taste or smell
Rainwater catchment systems have commonly found contaminants due to the location and isolation of rooftops.
| Contaminant | Source | Risk of entering Rain Tank |
|---|---|---|
| Dust and Ash | Surrounding dirt and vegetation Volcanic activity |
Moderate:Can be minimized by regular roof and gutter maintenance and use of a first-flush device |
| Pathogenic Bacteria | Bird and other animal droppings on roof, attached to dust | Moderate:Bacteria may be attached to dust or in animal droppings falling on the roof. Can be minimized by use of a first-flush device and good roof and tank maintenance. |
| Heavy metals | Dust, particularly in urban and industrialized areas, roof materials | Low:Unless downwind of industrial activity such as a metal smelter and/or rainfall is very acidic (this may occur in volcanic islands) |
| Other inorganic Contaminants(e.g. salt from seaspray) |
Seaspray, certain industrial discharges to air, use of unsuitable tank and/or roof materials | Low:Unless very close to the ocean or downwind of large-scale industrial activity |
| Mosquito Larvae | Mosquitos laying eggs in guttering and/or tank | Moderate:If tank inlet is screened and there are no gaps, risks can be minimized. |
Filtration
Gutters, Pipes, and Downspouts
First Flush
Storage
Extra Resources
References
- ↑ 1.0 1.1 Palau Catchment Manual http://ag.arizona.edu/region9wq/pdf/Palau_catchmentmanual.pdf
- ↑ Cite error: Invalid
<ref>tag; no text was provided for refs namedpacific