How Grey Water Can Be Used in a Bathroom How Grey Water Can Be Used in a Bathroom

Grey water is defined as waste water from the bathroom, laundry room and kitchen sink. It differs from black water which is waste water from toilets. It is possible to separate grey water and reuse it to irrigate plants, but it can also be treated and reused to flush toilets and provide shower and bathroom sink water. Black water can never be reused because of its nitrogen and pathogen levels. Additionally, water from the kitchen sink should not be recycled because of the garbage disposal which also adds nitrogen to the water. Water from the laundry, the shower and tub and the bathroom sinks, however, with the right system in place can be redirected, treated and reused for laundry, showers and hand washing.

Abundance of Grey Water

By some estimates, up to 65 percent of all water used domestically is grey water. This means that to put a grey water storage and treatment system into place could cut your water bill by more than 50 percent if you reuse it for laundry and showers. Depending on what the grey water contains will help determine how it can be reused, whether that is for irrigation purposes or for recycling it through your bathrooms and laundry rooms.

Grey Water in the Bathroom

If you want to be able to reuse grey water in your bathrooms, it requires a considerable amount of investment and work. A system must be put in place to channel the grey water through a filter and into a storage tank. You may also have to disinfect the grey water before it can be used in the shower, sinks or laundry.


The type and scope of the treatment system you end up putting into place will depend upon several factors. These include the amount of grey water you wish to reuse, the number and type of contaminants present in the water before reuse and how you plan on reusing it. It is possible to reuse the water you use in the bathroom, but filters and disinfectant procedures must be in place. Simple filters can separate hair and other debris from the usable water while disinfectants such as chlorine or iodine are necessary to kill any bacteria present.


The installation of a grey water system in your home requires the proper draining of the used water through a filter, into a disinfectant tank and into another tank for reuse. There are numerous ways to design and implement a grey water system that will depend upon your specific needs and the geography of your home. It is important to determine how you wish to reuse grey water first then set about implementing the system. Consider it carefully, for if you wish to alter your plans once the system is in place, it might be difficult to adjust.

You can reuse much of the water cycled through your home. A majority of it is called grey water–water used in the laundry, kitchen, showers and sinks. With the right system in place, water can be filtered, treated and recycled through the system and reused in the bathroom for showers, baths and sinks.

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