The Homesteader’s Guide to Greywater

While any person can survive without eating for three or four weeks before any serious health issues occur it is only possible to survive for three or four days without water.

The human body is made up of 70% water, a decent indication of why water is so important to everyone.

gravity greywater filtration system
A small, DIY greywater filtration system using sand.

Water is everywhere, we drink it, we wash in it, we clean house with it, our crops will grow if they have access to enough water. The mechanics of the earth’s ecosystem revolve around it.

Fortunately, we live on a large, blue planet of which 71% of the surface is covered with water. Consequently, with this enormous quantity of water, humanity has plenty to cope with all its varied and diverse requirements.

Unfortunately, 96% of the earth’s water is contained within the oceans, and this water is not suitable for irrigating plants and is not suitable to drink. We rely on a vastly important natural process of the earth called rain to supply water that we can use.

The sun heats the oceans, and causes water to evaporate into the atmosphere. As the vapor rises in the atmosphere it is cooled and forms a cloud and it is only when certain conditions are met that the water is released as rain.

This natural process removes the salt and numerous other impurities from the water.

The process of rain is providing the world with clean water that is safe for human and plant consumption, unfortunately, it is difficult to rely on the rain as a satisfactory water supply since being beyond our control it happens only when certain climatic conditions are met.

As the rain falls on to the ground it finds its way into rivers and lakes and eventually back to the sea.

Fortunately, a certain amount finds its way into underground storage areas or aquifers and it is the water from these aquifers that is the major source of our available water supply.

Some areas of the world have no water. It is estimated that as much as one-third of the world population does not have access to safe clean drinking water.

With global warming temperatures rising rainfall, as well as being unpredictable is reduced and is non-existent in some global areas. The reduction in rain frequency has affected the water deposits, they are getting low.

In some areas of America such as California, 80% of the water supply is used in farming and agriculture. Higher levels of usage mean that some rural areas that rely on wells are now without water.

Wells are expensive to drill, and it is not an exact science as to how much water can be released and for how long.

Some areas find that underwater reserves have become salty. Salty water cannot be used for irrigation or drinking. Desalination is a costly option, especially for individuals.

An alternative source of water is required both in areas that have little water, and those that have an abundance to protect the existing supply.

One extremely important source of water that is coming under scrutiny is water that has already been used and considered as waste and therefore returned to the ecosystem via a sewage plant. This supply of water is called greywater.

If greywater is such an important resource, we should investigate what it is, and how as a homesteader it is best to create an effective use of this alternative source?

Is All Waste Water Greywater?

Not all wastewater that is returned to the ecosystem from domestic environments is greywater. The organic load of wastewater is the defining factor of what is classified as gray water.

Sewage water is high in organic matter, and is called black water since the levels of organic organisms contained in it are dangerous to people and the environment.

Black water cannot be returned directly into the ecosystem since it would contaminate the supply of high-quality water in the aquifers. Although blackwater is highly contaminated and dangerous, it is also possible to clean and treat it so that it is suitable for return to the environment.

Since this form of water treatment is complex it is undertaken in regulated treatment plants that have been specifically designed for this. A scientific understanding of the effect of various chemical and biological processes is required to clean this water.

There is also increasing concern that countless elements of medication taken by the population may not be completely removed from the black water during the cleaning process, and could contaminate fresh water.

The criteria for cleaning this water is becoming increasingly complex, and hence expensive, especially as the volumes are large and increasing with population increases.

In simple terms, gray water is all other water that has been used in a domestic environment that is normally released into the drainage system. This is water from showers, bathroom, and kitchen sinks.

In some countries, 75-80% of all wastewater produced is gray water. High-income countries such as the United States have a higher water consumption per capita, but produce a lower level of gray water.

The U.S. is estimated to produce 52% of gray water from its wastewater total. The difference in these levels is attributed to different lifestyles and, more specifically, the level of water used by toilet flushing.

Amongst the homestead community especially in dry climatic areas the level of gray water could be as high as 80-90%.

The answer to this question is, as with various issues in America, both “yes” and “no”. Different states have different views on gray water several have different legislation that affects its legality.

Historically state legislation and plumbing codes did not distinguish between grey and black water, consequently, all wastewater from property was required by legislation to be disposed of through the main sewage system for treatment, or through a legal septic tank.

However, during the early 1990s, some states such as California realized that the use of greywater was an option to attempt to preserve dwindling water stocks. These states, although realizing the importance of this water supply insisted that it was disposed of by routing it into separate septic tank that would allow the water to be filtered before soaking away deep underground.

Numerous individuals who were desperate for irrigation water built an illegal system that diverted the water to where they required irrigation water. It was estimated that at one time 1.7 million illegal systems were in operation in California.

In Arizona countless people followed California’s example, with 13% of the population building and using illegal systems.

With numerous individuals objecting to the greywater legislation and restrictions, the code was eventually changed that made these previously illegal systems legal without inspections or permits providing they adhered to certain codes, and they produced less than 400 gallons (1.51 cubic meters) per day.

Arizona’s success encouraged other states, including Wyoming and New Mexico to change water codes to permit the use of gray water. Eventually (in 2009), the state code in California was upgraded to alter some restrictions regarding irrigation systems.

Greywater codes still don’t exist in several parts of the country. Some states regulate gray water the same as black water, and require a septic disposal system to be installed.

Others, like West Massachusetts and Virginia, allow greywater systems to be used only in houses that use a composting toilet.

Florida will not allow gray water to be used except for flushing toilets. Georgia allows greywater to be used to irrigate plants but only by using buckets, but they will not allow a simple gray water irrigation system to be built.

Washington state will allow small systems to be built without obtaining a permit providing certain performance guidelines are followed, but all other systems must adhere to the stringent specification.

There are still several barriers that apply to legal gray water systems around the county, but friendlier codes are gradually being implemented by various states.

Before installing any gray water system, it is best to check the relevant state plumbing codes and regulations imposed by the state environmental health department.

Benefits of Using Greywater

For numerous people in the Homestead community, environmental factors are a consideration for using this alternative water supply, however, the survival factor is the primary one.

It is an extravagance to pour valuable water into a septic tank, or simply allow it to soak into the ground without achieving maximum benefit from it.

As with any important resource, it is far better to attain beneficial use of wastewater before returning it to nature. Gray water usage also reduces the amount of water that needs to be passed through a septic tank system.

The Homesteaders Water Supply

Everyone is familiar with water being clear and clean and normally fit to drink if it supplied by a utility company, Greywater, by comparison, depending on where the water has come from looks cloudy and mucky, and certainly should not be considered for drinking.

Although Gray water is also safe to use for various features a little care and attention is required to ensure that it is used safely and does not contaminate drinking water supplies.

Few Homesteads will be supplied by mains water due to their location. They rely, depending on their geographic location on varied and occasionally several natural resources.

Generally, homesteaders will acquire water from wells, springs or occasionally rivers. There is, however, a large quantity of state legislation that are often different in each state, that dictate what can, or more importantly, can’t be done with water. Legislation affects both the various supplies and disposal of water.

I have a spring that activates if there is plenty of rain in the winter. The spring will fill my 14 500-gallon water deposit quite rapidly. I also have a well that I can draw water from in summer months if water starts to become low.

A rainwater harvest system is a handy additional supply, that is supplemented by a basic gray water installation for irrigating plants.

Enter Greywater…

The homestead and off-grid community is in a much better position to be able to render full use of this water supply, and there are also those in the greatest need of this resource. The homestead community have many uses for this valuable water supply.

  • Garden irrigation
  • Crop irrigation
  • Toilet flushing
  • Vehicle washing
  • Creating wetland garden features

Water that has been filtered and biologically cleaned has other uses too.

  • Washing dishes
  • Showering
  • Washing the dog

Nearly every one of the people who enjoy this alternative lifestyle are not connected to mains water supply, and for some living in geographic areas that are hot and have little or no rainwater resources often require some creative thinking just to be able to survive.

Since generally homestead properties are constructed in different ways to standard modular home access to plumbing systems is far easier, consequently changes to where water comes from and goes to either permanently or temporarily can be made by using a few simple cheap taps and piping.

It is, however, important to remember that plumbing for gray water is different from conventional plumbing, it is important not to use pipes that are too large as any solids will not flow well. Do not use U-bends, as these will clog up with debris it is far better to use flexible piping as a little movement will help to keep objects flowing.

For the majority homesteaders, the first task is that of separating wastewater, diverting waste from sinks showers, and even washing machines for alternative use whilst still permitting toilet waste to still run to a cesspit is relatively easy.

Toilet Flushing Is Money Down the Drain

Despite gray water being unsatisfactory for drinking, there are various uses for water that do not require the water to be of drinking quality.

One such example is the water that is used to flush toilets. Loads of households use mains water or a general house water supply for toilet flushing cisterns.

Despite modern cistern development that reduce the quantity of water used a high level of quality water is used to flush toilets. This is unnecessary, costly use of safe water due to convenience and a lack of thought.

Some homesteaders use chemical toilets even though numerous regulations inhibit their use.

Conventional toilet systems function perfectly well in homesteads with the wastewater being removed to the septic tank, however, the issue is that perfectly safe water from a limited and often fragile resource is required for them to function correctly.

Understandably for some, the thought of flushing toilets with a bucket of gray water can far from practical and perhaps distasteful. With some thought and planning, it is possible to use greywater for flushing toilets conventionally.

Greywater for Irrigation and Garden Watering

For many, the task of irrigating crops or watering the plants in the garden is undertaken by connecting a hose to a tap that is supplied from the main water supply, and that means for homesteaders with extensive crops a vast drain of clean water.

grey plastic container

When used for irrigation it is best to ensure that the water can soak rapidly into the ground and prevent from pooling.

This helps to minimize physical contact with the water, and prevents animals from drinking it. Some plants can be sensitive to wastewater, so don’t just pour it over the plants.

kitchen sink connected to the grey container
Here you can see a pipe running connecting my kitchen skin to the grey container I have set up outside. It’s not complicated or large system, I know, but it does the job.

It is advisable to match irrigation requirements with the amount of water being used since over-watering can cause problems with plants and crops that are being grown and will have a detrimental effect on the structure of the soil.

Understanding soil percolation rates help prevent pooling and run off, because if the water is not assimilated into the soil, it may pool or run off to another area where it can become a perfect breeding ground for mosquitoes and other pests.

Regional climatic conditions are also a factor in allowing absorption since a dry climate with little rainfall will not be as problematic as areas that have a higher consistent level of rain that could result in waterlogged land.

greywater system connection hose to garden
The collection “tank” has a second hose coming out which leads directly to the garden. Since I’m careful not to contaminate my water with chemicals, I don’t filter it. The hose leads directly to the plants, so I move it manually.

An irrigation system that is designed to operate by gravity is far better than one that relies upon pumps and long lengths of tubing, since the more complex the system, the more opportunities there are for problems, and maintenance is less frequent and simpler. Normally, the simpler the system the more effective and efficient it will be.

It is possible that matching supply to requirements may result in an oversupply situation, although for the majority geographic areas it is doubtful that this will be the case.

Storage of wastewater can be an issue however, as if this mucky water is released into rivers it will find its way into underwater aquifers where after a short time the nutrients become pollutants.

It would seem to make perfect sense to store the water so that it is available when required. As we have said if this water is released into a river it rapidly becomes toxic and a pollutant, the same happens if it is stored for more than 24 hours.

After this time the water turns from being a mucky nutrient-rich soup that is beneficial for plants to a toxic broth that is not suitable for plant growth and indeed a potential health hazard for people.

In its simplest form for a homesteader who is only growing a few vegetables, gray water can be piped directly to the vegetable patch. However, few devices are rarely that simple, since the water will contain organic material, hence care and attention are required.

Take care, not to water plants that do not require water in dry, hot seasons as countless have adapted to these conditions. Not all plants, especially some vegetables, will accept greywater as they are too sensitive.

Care should be taken to water below ground, and not to spray or put gray water directly onto plants that are going to be eaten.


There may be certain situations where they may be a greater supply of greywater than is required; this could provide the opportunity to create wetlands that would be aesthetically satisfying, as well as providing a natural habitat for a diverse range of animals and vegetation. Wetlands also allow water to return safely to the ecosystem.

Wetlands are basically areas that are oversaturated with water. You can learn more about them here.

Possible Contaminants

For those who only produce a slight amount of gray water that can be used virtually immediately for irrigation, it is not necessary to treat the water, although care should be taken as to what is in it.

Although there are several methods for gray water treatment, there is no established design that suits all situations. Treatments differ in their characteristics to consider, pollution and organic loadings, the quantity and the final application.

First establish where the water is going to come from, what the water is going to be used for and, and of course quantity involved.

The climate of a geographic location will have a great influence on treatment types since this will identify the supply available and how much water is needed for the home and irrigation.

Countless who live in standard houses aim of using gray water may be for environmental reason, by reducing the amount of wastewater being treated unnecessarily in utility water treatment sites, and returning it directly to the ecosystem.

Similarly, there may also be homesteads for which water supply is no issue, and again only require to help to protect the earths water supply.

The option for those in this fortunate situation is simple: route all wastewater into the septic tank since this utilizes natural biological bacterial processes to filter and return water to the ecosystem.

Those that want to be able to use gray water first be aware of any chemicals and cleaning products that are being used. There are countless homemade products available for maximum cleaning situations that are not made up of harsh chemicals.

As we’ve already said, water that is used to flush toilets is not gray water, it should not be used, and should be routed to the septic tank.

Wastewater can be taken from kitchen sinks, bathroom sinks, and showers.

However, some people do not like to use water from a kitchen sink since it will contain much higher concentrations of organic substances, nitrogen, grease and oil, in addition to detergents from the dishwashing processes.

Some states do legislate against the usage of sink water, however some states such as Montana, Arizona, Oregon, and Washington do allow this water to be used.

With care over how washing up is undertaken the amount, organic material can be reduced significantly from washing water that along with a simple filter will allow this water to be a valuable addition to a gray water supply.

There are often those that are hesitant to use shower water as they will be traces of human waste within the water. There will be however human debris such as skin hair and beard trimmings found in water that has come from a bathroom sink.

Let’s remember we are talking about wastewater that is going to have all kinds of contaminants. What is the water going to be used for? We are not looking to drink the water, but to use it possible to flush toilets and certainly as a source of irrigation water.

Generally, in the homestead community, especially those that live in dry areas with a limited supply of water are not likely to produce massive quantities of wastewater, consequently, the major usage is going to be irrigation rather than indoor usage.

The Importance of Filtration

The contents of the wastewater water for every individual is completely different since it depends on the dietary habits of the household and the type of cleaning chemicals that are used.

Filtration is the utmost important technique and is one that can be implemented relatively easy with DIY solutions that are low in cost.

Taking care and attention to what is being put into the sink for washing is a worthy start. Clear any food debris from plates and cooking utensils, for example.

For those worried about disease transference affecting the eggs, a compost bin is a worthy idea. A simple sieve or piece of muslin over the waste outlet can also help remove debris that does reach the sink.

The wastewater can then be passed to a container that is filled with materials that will continue the filtration process.

Various natural materials can be used to filter the gray water to remove maximum biological materials. The best method is to use coarse materials to start the process, and gradually reduce the size to that of sand.

Other natural materials that can be used to filter the water are ceramics, charcoal, limestone, clam shells and coconut shells.

The size and number of containers are dependent on the quantity of the water that is passing through the system and how dirty the wastewater is to start with.

The water that emerges from this system should be clear and clean, and certainly suitable for crop irrigation.

The problem with water is that, as with spring and well water, it can look clear, but still be loaded with toxins and chemicals, some of which can be harmful to plants and people.

A Simple Permaculture-Based System

Another option in treating grey water is by using a simple Permaculture-based treatment system.

Again, care with the choice of detergents being used and what foodstuff is going into the grey water, but this system will remove most problem substances. This method of treatment works by physical filtration and biological cleaning of the water.

Filter the water through a worm farm using bark or wood cuttings to initially remove any debris or food materials. Worms will eat any biomaterial, allowing cleaner water to pass through.

This filter will need to be cleaned out and changed periodically but this provides a wholesome bio-mass material that can be used as compost to feed plants or dried and burnt in a biomass furnace.

Water that passes through enters a grease trap a tub that allows any oil or grease to be separated from the water.

Oil that rises to the top of the drum water can be drawn from lower down in the drum. Grease and fat can be removed periodically, and used as a feed for fruit trees.

The water can then pass into containers such as old baths in which mini wetlands have been created. The bath is sectioned with wooden baffles that are filled with gravel to prevent the water flowing straight through.

Wetland plants planted in the gravel help to clean the water that can then pass through directly into an irrigation system or into a tank that can be utilized for toilet flushing. The wetland plants thrive in this environment and create biomass that has several other uses.

The location of any water treatment is an important factor, keeping it close to a property requires less pipes that can become blocked. Wherever possible, use gravity to move the clean water to where it is required.

I use small 12V water pumps that are designed for RV use to pressurize water in my house. These are also perfect for moving water around outside, they have built in filters, and can be powered by solar panels as well.

As with any DIY project, they don’t always work well initially: the odd adjustment or alteration is perfectly normal. No point in stressing over this on occasion it is necessary to turn back to start again.

I never throw anything away, especially any piping or fittings, as I know that I will always find a use for them.

Chemicals in Grey Water

The contents of wastewater are also important. We have seen that the biological contents of wastewater are a valuable natural resource for plants.

However, that is only the case if the water is sent directly to the irrigated area, and preferably underground irrigation since the biological material can build up on the ground causing smells and attracting rodents.

Although the situation regarding cleaning chemicals sounds a little confusing, with a little thought and taking time to read content labels, it is possible to reduce if not prevent all dangerous chemicals from finding their way into the greywater supply.

Soapy water is safe to spray on plants to reduce various pest infestations, and, therefore, is not particularly harmful, however, there are other chemicals contained in certain products that can be harmful.

Personal care products such as toothpaste, shower gel, shampoo, and conditioner all need to be checked. There are now countless products available that are plant-based and indeed it is possible to create several yourself.

Salt and Sodium Compounds

Salts will build up in specific soils and create an environment that will inhibit plant growth by reducing their ability to accept water and nutrients. The safe amount of salt depends upon the properties, climate, soil, and plant types.

Areas that have decent, frequent rainfall are not affected to such an extent by salt as the water will wash it away.

However, dry areas that have salty groundwater additional salt will build up and cause problems. Various fertilizers are also high in salt.


This chemical is a micro toxin and is harmful even in slight amounts. Products that contain boron, including the laundry additive borax, should be avoided.

Chlorine bleach

Bleaches containing chlorine an excellent product for destroying germs in kitchens and bathrooms will kill microorganisms, including beneficial soil microbes.

Hydrogen peroxide bleach is a worthy alternative, alternatively, turn off your gray water system when bleach is being used. Learn to purify water with bleach and the right bleach to water ratio to use.

Alkaline compounds

Certain products will raise the pH level of the water. This isn’t a problem for the majority of plants, although certain plants prefer acidic conditions.

In general, bar soaps will raise the level while liquid soaps do not. Cleaning products that are PH -neutral are the best ones to utilize.

If this untreated water is stored in a container for later use it will become smelly, and the nutrients start to turn toxic due to microbial growth.

This will render this water useless. Consequently, to be able to store this water for later use it needs to be treated.

Is There a Future for Gray Water Usage?

With continued population growth, and current trends in economic development, there is an ever-increasing demand in water for agriculture and industry.

With an increasing standard of lifestyle, dietary changes, and climate change, there is no doubt that society will struggle if it continues to use the existing water supply model.

We have seen that most of the homestead community who uses gray water tends to treat it using DIY techniques with reused or salvaged components although the science behind the processes is complex the application is very basic.

In contrast to this, the use of gray water within traditional housing is beginning to be embraced by property developers. Properties are starting to be built and old ones retrofitted with sophisticated modules that use sophisticated technology.

The technology within some of these devices that use advanced filtering techniques and UV radiation to produce high-quality gray water can often use the process to provide other effects in the home such as heating.

Several of these modules are at this stage too expensive and possibly to power-hungry to produce them satisfactory for homestead use, however, the provision of economical equipment will be available soon.

Is Grey Water Safe?

There have been no recorded incidents of illness being transferred or caught from gray water (from what I researched).

Are chemicals a viable treatment option?

Chemicals can be bought that can clear wastewater, and reduce microbial activity. I like the majority homesteaders, am always wary of chemicals especially if used they are going to be used regularly, since they can often influence the ecosystem finding their way into crops.

Natural processes eco-friendly technology without chemical additives or toxic by-products that respect the environment are always preferred techniques.

grey water pin image

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