A washing machine produces greywater that usually contains dissolved detergent and dirt.
The term “greywater” refers to all household water, except for toilet water. This gets known as blackwater.
Greywater is wastewater that gets generated from laundry, dishwashers, kitchen sinks, and baths. It can get recycled in your home to use for things such as toilet flushing and landscape irrigation.
Greywater may contain traces of dirt, food, grease, and certain household cleaning products. While greywater may look “dirty,” it is a safe and even beneficial source of irrigation water in a yard.
If greywater gets released into rivers, lakes, or estuaries, its nutrients become pollutants. But to plants, they are valuable fertilizers. Aside from the obvious benefits of saving water and money, reuse keeps it out of the sewer system. Thereby reducing the chance that it will pollute local water bodies.
Greywater is completely safe for irrigating plants. As long as you’re only putting biodegradable products down the drain.
Washing machines are actually the easiest source of greywater to reuse. It is because greywater can get diverted without cutting into existing plumbing. Each machine has an internal pump that automatically pumps out the water. You can use that to your advantage to pump the greywater straight to your plants.
Basic Greywater Guidelines
Graywater systems get embraced by authorities. Especially in regions where water is scarce. Most greywater systems need a permit to install. As well as a licensed plumber. But the washing mac is unique. That is explicitly legal for homeowners to install it without a permit.
Regardless, greywater is different from freshwater. It requires different guidelines for it to get reused.
- Don’t store greywater (more than 24 hours). If you store greywater the nutrients in it will start to break down, creating bad odors.
- Cut contact with greywater. Greywater could potentially contain a pathogen if an infected person’s feces got into it. Your system should get designed for the water to soak into the ground. Not be available for people or animals to drink.
- Infiltrate greywater into the ground. Don’t allow it to pool up or run off. Knowing how well water drains or the soil percolation rate of your soil will help with proper design. Pooling greywater can provide mosquito breeding grounds, as well as a place for human contact with greywater.
- Keep your system as simple as possible. Avoid pumps, avoid filters that need upkeep. Simple systems last longer, need less maintenance, need less energy, and cost less money.
- Install a 3-way valve for easy switching between the greywater system and the sewer/septic.
- Match the amount of greywater your plants will receive with their irrigation needs.
- Don’t allow pets or children to come into contact with it.
- Make sure to water it underground or under mulch (never above ground)
- Wash your hands thoroughly after coming into contact with it (try to use gloves)
- Don’t use greywater if someone in the house has an infectious disease, or if you have a new baby in the house.
- Never allow your greywater to run off onto a neighbor’s property, stormwater system, or a creek or waterway.
Is washing machine greywater safe?
Here are some of the components in most soaps. They are most likely to cause problems to plants in your yard.
Phosphorus
Small amounts of phosphorus can be useful for plants, and it’s a major component of fertilizer.
But when it gets into waterways, it can cause excessive algae growth. it can lead to toxic algal blooms.
The effect on your soil gets varies depending on your soil type.
•Clay soils can deal with more phosphorus. It is because the phosphorus binds to clay minerals and doesn’t leach away.
•Excess phosphorus can leach into groundwater when in sandy soils,
•Australian soils are usually low in phosphorus. Some native species can’t tolerate high levels.
Sensibly, modern laundry detergents no longer contain added phosphates, so this issue is largely a thing of the past.
Salts
All laundry detergents contain salts. Typically sodium salts. Such as sodium nitrate, sodium sulfate, sodium phosphate, and sodium silicate. It makes them highly saline.
Sodium is particularly detrimental not only to plants but to soils. It affects the soil’s permeability and causes a loss of structural stability.
Frequent long-term use is likely to harm your garden. Unless you take care to spread your laundry greywater over a large area.
Alkalinity
Laundry detergents are also highly alkaline, that is, detergents that have a high pH. A pH that’s higher than 10 helps dissolve organic dirt, such as grease, oils, and food scraps.
For reference, a pH of 7 gets considered neutral, but your highly caustic oven cleaner has a pH closer to 12.5.
Most biological systems prefer a pH between 6 and 9. And greywater with a high pH is likely to harm many plants and soil organisms.
We consider the total load of problem chemicals that will accumulate in your garden over time. Not just their concentration when you first put them on.
The larger the irrigation area the more you’ll spread the chemical load. Thleastum recommended area is 150–200 m2.
Potential impacts are very much dose-dependent. Try reducing the amount of detergent you use. Providing the reduced amount will still get your clothes clean enough.
What Are the Advantages of Greywater?
Using greywater has many benefits. It can:
- Lower your water bill
- Extend the life of your septic system
- Save vast amounts of water
- Save energy by replacing water that would otherwise get treated to drinking water quality and is not treated at a sewage treatment plant.
- Increases water efficiency, which in turn, reduces pressure on strained water supplies.
- Reducing general Sewage Load. By separating greywater from sewage, you can lower the amount of water sent to local sewage treatment plants.
Here are 10 questions to consider before draining washing machine water into your yard.
How much water does your landscape need?
First, understand how much water your grass, plants, and trees really need to thrive. Second, stop and learn how to manage your irrigation controller.
Third, find and fix leaks in your irrigation system. These steps are so effective at saving outdoor water that many cities offer free workshops to help you with each one.
How much greywater will your laundry produce?
Every load of laundry creates from 10 gallons of greywater from a small front loader to 50 gallons from older top loaders.
Consider how many loads you do a week and if you can use all that water efficiently. Graywater should only get stored if the tank has a tight cover. This is to restrict access and prevent a habitat for mosquitos and other pests.
Do you want to grow food with greywater?
When it comes to growing food, greywater is suitable only for citrus and nut trees. It should not get used to growing vegetables, fruits, and herbs that could come in contact with the water.
What do you wash?
It is unhealthy to use gray water in your yard when you wash diapers, oily rags or clothes. They get stained with chemicals, such as antifreeze. Clothes of someone who has an infectious disease.
Where are you going to use the greywater?
Keep greywater a minimum of four feet away from the exterior walls of your home. It can stain and crack the foundation if you drain it close to your home.
Are you ready to change detergents?
It’s important to know what is in your detergent before pouring laundry water onto your plants and into the ground.
Will greywater attract your children or pets?
It’s not healthy to allow children or dogs to play in greywater.
Are you ready to ditch your water softener?
Water softeners add salt to your water. Desert soils are already salty and that much salt can build up in the soil and kill even sturdy plants.
How well do you know your plumbing?
A laundry-to-landscape system is more complicated than a simple DIY project. It’s also only practical if your laundry facility is next to an exterior wall. Unless you know to plumb, experts recommend you call in a professional. It is to help set up even a simple greywater system.
Do you know where your greywater goes now?
Make sure that wastewater is highly treated and reused. It can get used to cool Nuclear Generating stations, restore groundwater, and store underground for future use. To irrigate large grassy areas, such as schoolyards, parks, and golf courses. Check with your city. It’s likely the water you send to the sewer gets put to good use.
How to Use Greywater
Diverting your greywater from your washing machine to mulch basins around trees and bushes is an effective way to use this resource.
This gets known as “laundry to landscape”. It captures the greywater from the drain hose of your washing machine, sending it to your plants through a 1-inch tubing. You do not need to alter the existing plumbing.
Laundry machines get equipped with a pump to push the wastewater out of the machine and into a sewer pipe. It uses a washing machine’s built-in pump to distribute the wastewater. It goes through a system of subsurface pipes to irrigate individual plants around the yard.
The water flows out into mulch-filled basins around each plant, where the roots can access the moisture.
This design is most effective for watering fruit trees, berry bushes, edible vines, and other large permanent plants. It is not useful to irrigate lots of little plants, like flower beds, lawns, and annual vegetables.
How do we get the greywater onto the garden?
There are various devices to access the greywater before it reaches the sewer, and divert it to the garden – visit your local hardware, plumbing, or irrigation shop and ask for advice. There must always be a way to re-divert the greywater back to the sewer, for instance during winter, when the water is not needed.
Another issue to consider with greywater use is that you may not have the amount of water you need when you want it. Also, soils have become so dry in drought-stricken areas, that water administered to plants can runoff. Smaller plants can still survive under these circumstances (although not thrive) but established fruit trees with their greater needs (20 or more liters of water a day when fruiting) may drop fruit or not set it at all.
By fitting slotted flexible plastic agricultural pipes around your fruit trees, you can give them good deep water when they need it. Such as when they are setting fruit (at flowering time) and when approaching harvest time. It is amazing how much you can increase the size of your fruit by watering it when the fruit is growing. By watering with the pipes, you can get water down deep into the root zone – difficult to do otherwise.
The pipes should get fitted 30-50cm deep into the ground around the trees, at a distance of about 30 cm from the trunk. A new tree will need 2 pipes, whereas an older established tree may need 4-6 pipes to receive adequate water.
Make sure to leave the pipes sticking out of the ground 50mm or so, so that they don’t fill up with mulch too easily. When you are topping up mulch, cover the tops with upturned plastic pots.
Disadvantages:
•You can’t irrigate areas uphill from the washing machine (the pump isn’t strong enough)
•You also can’t irrigate plants on a slope. Though you can run the water downhill from the machine to irrigate a flat area below.
•Don’t use this method if you’re washing dirty diapers in the washing machine. That makes it blackwater.
•Don’t apply the greywater to plantings along streams or on the swampy ground. To avoid contamination.
•You may only use biodegradable products in your washing machine. This means no bleach, borax, or sodium.
How do we ensure good soil health if using greywater in the garden?
Sandy soils will cope far better than clay soils with greywater. So if you have heavy clay soils, use as little soapy water as possible on it.
Add gypsum each year for the calcium it contributes, which helps the soil deal with salinity. Apply at the recommended rate (usually 1 kg per square meter on garden beds, and 50gm per m2 on lawns).
Don’t add lime or dolomite for calcium as they will both raise the pH of the soil and greywater is already doing this.
With all soil types, it is important to keep up the levels of micro-organisms, nutrients, and organic matter. This will help the soil deal with any potential problems from the greywater.
So each year add plenty of compost and good quality mulch. These are such as composted recycled garden waste sold by councils and nurseries.
Never use greywater on the potting mix. It causes the organic matter in it to break down and will clog up its drainage capacity.
You are simply diverting the greywater to other pipes that lead to the yard. Using greywater can water 20 locations of plants from one top-loading washer cycle. A front loader can yield enough water for 8 locations. Be sure to always use plant-friendly detergent.