Permaculture - Gray water, basics (lesson 38)

A typical European family uses 450 liters of water a day for bathing, cleaning, flushing the toilet, and cooking. Additionally, those who have gardens use more water to irrigate them (lawns with perfectly trimmed grass are especially water-absorbing).

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Water can be divided into three types - clean, gray, and black water

• Clean water is reusable by humans. This is, for example, water left in the glass, which we can still drink the next day.
• Black water is water that cannot be used a second time - heavily contaminated with detergents (e.g. bleach, chlorine, or washing up liquid) or flushed down the toilet.
• Gray water is a stage between the two previously mentioned: shower or tap water, contaminated with soap (preferably gray, natural) or dust, dirt. It cannot be used by humans a second time, but it can still be used for watering plants in gardens.

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There are many advantages to reusing gray water: as you know from previous lessons, potable water is a very valuable and exhaustible resource, so it should be conserved. In addition, the quick filling of septic tanks and sewage systems generates additional costs for society and the use of additional water additional costs for us.

Hints:

• it is best to use gray water for watering ornamental plants, not the ones we eat. At least make sure the water does not touch edible parts of the plant (it's okay to use it under the fruit tree but not to water the salad). Although the risk of food poisoning from watered with gray water is very low, it can happen (depending on the ingredients it contains)
• gray water must not contain chlorine, boron (borax), strong chemical cleaning products
• if you do not want your greywater to be very alkaline, pass it through the mulch and fertile soil to balance the pH
• do not use the greywater system in the freezing season
• use water on a regular basis. If kept for too long, it becomes harmful to plants

how to instal

Gray water, used to water the garden or to flush the toilet, requires special installations. In Europe and the USA, ready-made installations can be purchased in DIY stores, unfortunately, I do not know what it looks like in other parts of the world (if you have any information, feel free to write in the comments). You can also prepare the installation yourself, but you must be aware that it is a difficult task that requires time, appropriate training, and financial resources.

If you still want to try your hand at it, I recommend you to read the book "Create an Oasis with Gray Water" by Dan Chiras. You can also check out the website https://oasisdesign.net/ - it's very ugly, it stopped in time in the '90s, but it contains a lot of extremely useful information.