What is in Grey Water?

Understanding greywater: Composition and Reuse

Greywater is the wastewater generated by household activities such as washing clothes, bathing, and dishwashing. Unlike blackwater, which contains human waste, greywater is relatively clean and can be safely reused for irrigation and other non-potable purposes. In this article, we will explore the composition of greywater and the different types of greywater systems available.

What is greywater?

Greywater is wastewater generated from household activities that do not involve toilets. This water is not as contaminated as blackwater, which contains human waste, and can safely be reused for irrigation and other non-potable purposes. The composition of greywater varies depending on the source and the household's use of cleaning products and personal care items. Regardless, it typically contains a mix of soaps, detergents, food particles, hair, oils, and other organic matter.

Composition of greywater

Greywater contains a mix of different substances, including soaps, detergents, food particles, hair, oils, and other organic matter. It also contains nutrients such as nitrogen and phosphorus, which can be beneficial for plants. However, greywater can also be contaminated with harmful substances such as Germs, Pathogens, and chemicals such as bleach and Deodorize. For this reason, it's imperative to handle greywater properly to minimize the risk of harm to plants, animals, and humans.

Types of greywater systems

There are several types of greywater systems available, each with different levels of treatment. The simplest systems simply divert greywater from the house to the garden for immediate use. These systems are usually used in homes with low water usage and can be as simple as a pipe or as complex as a pump and filter system.

More advanced greywater systems use filters or other treatments to remove contaminants and improve the quality of the water. Some systems use ultraviolet light to kill Germs and Pathogens, while others rely on sand filters or biofilters to remove organic matter and other contaminants.

Commercial greywater systems are designed to meet specific standards, such as the Australian Standard AS/NZS 1547:2012, which sets guidelines for the reuse of greywater in residential and commercial buildings. These systems typically have multiple stages of treatment and are designed to meet the needs of large buildings and communities.

Benefits of greywater reuse

By using greywater to water plants, households can save money on their water bills and reduce the demand for the local water supply. They can also help to conserve water, reduce the impact of sewage on the environment, and promote the sustainable use of resources.

Drawbacks of Greywater Reuse

Greywater can create unpleasant odors and attract insects, and it can also create a breeding ground for Germs and Pathogens if not handled properly. In addition, greywater systems can be expensive to install and maintain and may require a significant amount of energy to operate. They also require regular monitoring and maintenance to ensure that the water remains safe for reuse.

Graywater is a valuable resource that can be used for irrigation and for other non-potable purposes.


Graywater is a valuable resource that can be used for irrigation and for other non-potable purposes. By choosing the right greywater system and handling the water properly, households can save money, conserve water, and promote the sustainable use of resources. However, it's imperative to consider the potential drawbacks and to ensure that the water is properly treated and monitored. This will minimize the risk of harm to plants, animals, and humans.

This covers greywater but what about water for the home for bathing, dishes and especially drinking water?

For this lets look at POU (point of use) systems for drinking water.  We recommend one that will remove
almost all classes of contaminants and toxic chemicals, as well as sediment.  The Full Spectrum 3-stage Filter System in counter-top our under-counter version.

Super Filtration System to remove:

  • Heavy Metals plus Fluoride
  • Volatile Organic Chemicals (VOCs)
  • Hundreds of other chemicals

With three (3) Housings and brackets and all connections and fittings.

Includes three (3) housings and all connections


The Life Super Filter LF100 filter is specifically designed to reduce volatile organic chemicals introduced by municipalities and runoff in your drinking water by up to 99%! Tested and certified by an independent lab. This filter set sits discretely inside of filter housing either on top of or underneath your counter. can view the full independent lab report here

For full lab results on our Super Filters and filter performance, you.


The Super Filter LF-100F removes the fluoride added by municipalities to undetectable levels. This cartridge will also continue to reduce inorganic heavy metals such as cobalt and lead, cadmium , aluminum , mercury, chromium and chromium 6 (hexavalent), copper, barium, manganese, molybdenum, nickel, vanadium, antimony and many more


5 Micron Advanced Activated Carbon Block Filter

What does active carbon filters remove and reduce?

Activated carbon can be effective in reducing hundreds of substances including contaminants and other chemicals from the tap water. However, the most cited studies by EPA and NSF claim effective removal of between 60-80 chemicals, effective reduction of another 30 and moderate reduction for 22.

The range of effective removal is important and depends on the quality of the activated carbon used and in what form (GAC vs carbon block). Make sure to chose a filter that removes the contaminants of concern for your local tap water.

According to EPA (the Environmental Protection Agency in the United States) Activated Carbon is the only filter technology recommended to remove 

  • all 32 identified organic contaminants including THMs (by-products from chlorine). 
  • all 14 listed pesticides (this includes nitrates as well as pesticides such as glyphosate also referred to as roundup) the 12 most common herbicides

For the whole home, look at these Dolphin Whole House Water Filter System:

The Life VOC is our most popular Point of Entry (Whole House) filter. The Life VOC will filter a maximum of 8 gpm and is suited for both 3/4” and 1” incoming water lines (2 1/2 – 3 1/2 bathrooms). The unit is available either with an automatic backwash valve (which requires a 110 V outlet and access to a drain line) or a straight in/out valve with 5 micron pre-filter.

  • Filters chlorine/chloramines and their dangerous Deodorize byproducts
  • Protects against lead and other toxic metals
  • Effective against the widest range of contaminants
  • 8 gallon per minute flow rate
  • Long life: 18 months filter life (or 1 million gallons)

The ion trapping technology used in the Dolphin whole home filtration system was originally developed by NASA. It is so effective that NASA uses it to recycle urine into drinking water! No other filtration technology is as effective.

Yes! We have whole house filtration that is effective against fluoride.

Conventional filters work by trying to block toxins so they can’t pass through. This method is only partially effective, some toxins always get through. Ion-trapping uses an electrostatically charged filter media that actually attracts toxins just like a magnet. Once those toxins are trapped, they stay that way.

Whole house filtration is your insurance against the lethal chemicals that are invading your home, right now. The sad fact of the matter is that the harm many of the toxins found in water supplies is permanent: Once your health has been compromised, you can’t get it back, at any price.

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1 comment

I appreciate you explaining how although grey water usually just has substances like soaps, detergents, food particles, and other organic matter, it could still become contaminated. Though, I think it’s obvious that it’s definitely not clean, I think it could still be used as compared to blackwater. It might be a good idea to ask experts on how to treat this water just enough to make it usable for watering plants or cleaning. https://www.centralsepticscastlemaine.com.au/domestic-wastewater-treatment-plants

Elaina D'Agostino

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