What is Greywater?

Greywater is described as gently used waste water that comes from sources such as the bathroom, kitchen and laundry. It is relatively clean and cannot be compared with the water from toilets (blackwater). Generally, any water that is drained from the house other than toilet water can be described as greywater. It may also contain traced of food, grease, hair, dirt or particular household cleaning products.

As much as it may look dirty, greywater can be reused for other purposes and does not necessarily have to be disposed of into the sewage system as other types of waste water do. This means that it is not really waste water but could be repurposed for safe and beneficial uses such as yard irrigation. It therefore serves to substitute fresh water for some purposes thus allowing for water conservation as well as reducing the amount of water that is sent into the sewage system for treatment.


Different Ways to Collect Greywater

  1. Manual Collection

Greywater is collected from laundry, kitchen or bath water. The systems for collecting greywater vary from manual to completely automated with the manual systems being the simplest to use and the ones with the least costs of maintenance. The manual systems require nothing more than a bucket and jug for collecting greywater by hand. The water can then be used either for irrigation plants or as a substitute for using fresh water for flushing.

  1. Simple Piping

The second more complex system creates an automated connection between laundry and the landscape. This system uses plumbing connections between washing machine’s waste water drain pipe and the lawn. Here, the water flows via underground piping into the yard where it is used to irrigate the land. It has a low cost of materials and requires some maintenance to ensure that the plumbing does not become clogged up with residue from the soapy water. This kind of system can be built by oneself with little effort and training plus the materials required such as hose pipes and connectors.

  1. Integrated Sewage and Piping

The third system involves integrating the whole houses plumbing into a greywater collection system. These systems are the most expensive and the most maintenance intensive options available. They also require that one hires professionals in order to ensure that the work is done properly. The systems usually connect bath, laundry and kitchen drains to a system that dispenses greywater into a collection tank. The water usually needs to be used within 24 hours of collection in order to avoid bacteria from growing to numbers that cause foul smells. The water can however be treated with chlorine or iodine to allow for longer storage.

Some systems can even allow for the merging of greywater to toilet plumbing ensuring that one does not flush the toilet with fresh water. The systems can be further integrated to include greywater outlets that merge into the existing sewage systems to ensure there is no overflow. Some systems can also come with an emergency shut of switch to ensure that in case the system fails, there is no backflow into the main freshwater piping. The amount of piping and pumping involved in these most complex systems means they are more susceptible to blocking due to residual soap. They therefore need more maintenance than other systems.

Benefits of Using GreyWater

  1. Fresh water Conservation

Use of greywater reduces the amount of fresh water used up in the household for other functions. The reusing of greywater to flush toilets and water plants reduces the load of fresh water required and if enough people make the same choice, the water demands can be reduced so drastically as to positively impact the environment. This is particularly important in regions experiencing dry climates or going through droughts.

  1. Reduction of water wastage

The use of freshwater for all the different functions in a house produce lots of waste water that all ends up flowing into the sewer systems. This creates unnecessary wastage. By reusing greywater for one other function before it is dumped into the sewage, the amount of water wasted can be halved. Thus, it means fewer resources can be diverted to sewage treatment and that the saving of even an extra liter of water which could have been used before its disposal increases as well, thus increasing water use efficiency.

  1. Reduced energy consumption

With reduced fresh water demands for each household, there is reduced energy demand required to pump the water into the house. Secondly, water reuse reduces the load that treatment centers have to handle in ensuring that it is purified thus reducing total energy required by both water distribution and sewage purifying companies. Reduced energy use means less electricity and in turn, fossil fuel use is also cut down eventually helping to reduce greenhouse gas emissions. It means that energy can be diverted into other resource intensive requirements or stored for later use.

  1. Reduced chemical consumption

The reduction of water sent to sewage plants also leads to reduced levels in the amount of chemicals used in treating the water. With a smaller load, sewage treatment plants do not require as much use of chemicals which is beneficial to the environment as it reduces both the cost of sewage treatment as well as reducing the demand for chemical production that goes to benefit the environment. It also reduces the chance of accidental dumping of chemical waste by sewage processing companies. Greywater use also reduces the need to fertilize the yards with chemical fertilizers due to the nutrients the water already contains.

  1. Beautification of landscapes

The use of greywater to water yards provides an alternative source of water to plants, especially in regions where plants lack it. Regions that use reclaimed greywater thus provide alternative use for water that would have gone to waste. Therefore, it creates beautiful landscapes as plants maintain greenness and bloom, even in regions where the climates are harsh. Coupled with other technologies such as the use of mulch and drip irrigation, the water provided can last longer to ensure the beautiful state of one’s yard is maintained even during the driest of seasons.

  1. Reuse of nutrients

The use of greywater reintroduces nutrients that would have otherwise been lost to the sewage system. Kitchen and bath water contain a lot of organic material that is not harmful to plants. This is unlike blackwater where the organic levels are too high. Blackwater also has lots of harmful bacteria e.g. E. coli that could cause disease if they contaminate the soil. The greywater provides plants with good nutrients that go towards increased beautification.

  1. Organic filtering of water

The greywater used in watering plants is purified by both plant and soil action which negates the use of chemicals that might, in excess, harm the soil and the organisms that live within it. Organic filtering serves to ensure the environments safety.

  1. Groundwater recharge

The greywater used often ends up being filtered by the soil as it moves down and ends up in the ground water where is replenishes the levels therein. This is a good thing as it ensures waterways such as rivers sourcing their water from the underground aquifers are always fed.

How the Greywater System Works?

The process involves three steps which include:

Collection of greywater

The greywater can be collected from the sinks, baths or washing machines by use of basins or through piping. The problem that occurs with this is the kinds of soaps used. Some soap have harsh chemical that can damage the plumbing system over time. It is recommended that one uses organic soaps as they are less likely to cause harm.

Secondly, the use of plumbing is recommended as it requires less maintenance and will not tire the individual as much as manual bucket collection will. The system can also make use of pumps to transport the water to collection sites. This allows for storage of waste water while it is not in use. The added challenge from this is the fact that the pumps may be affected by the chemicals within greywater over time.

Storage and treatment

The water is usually collected in a storage container afterwards. Storage is recommended for less than 24 hours to ensure bad smells do not accumulate. It is also recommended that one treats the water with chlorine or iodine to ensure that the stored water does not produce foul smell, if the plan is to store the water for longer.

Use of greywater

The greywater system should be connected in the most appropriate way to ensure look term use. It is best to have the system both flush toilets and pour into the yards. The water can be transported via use of gravity or pumps, but ideally, there should be a way to divert water into the usual sewage path if it is not needed. Also, there should be an emergency cut off in case of failure of the system to prevent backflow of the greywater into fresh water systems. The greywater can also find use in any other non-contact way such as with washing garden tools and the driveway. When used for gardening, the plants should not be acidophilic (plants that do well in acidic soils) as greywater is usually alkaline in nature due to the use of soaps.

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Rinkesh is passionate about clean and green energy. He is running this site since 2009 and writes on various environmental and renewable energy related topics. He lives a green lifestyle and is often looking for ways to improve the environment around him.