Water-readings

Greywater recycling is the practice of reusing wastewater produced from the washbasins, bath tubes, shower drains and washing machine after a particular treatment.

The main operating parts of a greywater recycling system is:

1. The greywater pipelines have to be separated from the black water. The greywater is collected in a special water storage tank before its treatment process. The size depends on the water amount treated and its material must be resistant to commonly used chemicals (e.g. chlorine).
2. Then, the collected greywater is treated  using a set of filters and chemical substances , depending on the technology followed.
3. The treated greywater is collected in a storage tank to be used within 24 hours.

Water-readings

Greywater recycling in Malta’s national swimming pool

The national swimming pool of Malta is the main venue for the national water polo leagues, various international tournaments and important ‘swimming events’. It hosts approximately 800 athletes a day.  Greywater generated from the showers is a valuable water resource, when properly treated and reused. For this purpose, a greywater recycling system was installed by the “NCWR Programme in the Mediterranean” using a new filtration technology. The system is based on advanced technology that produces water of high quality, free from microorganisms and hazardous substances. The recycled greywater is used for toilet flushing in the premises and for landscape irrigation.

Greywater system in a football course in Cyprus

Another example of installing a system for greywater recycling comes from Cyprus also installed in the framework of the “NCWR Programme in the Mediterranean“. In the football course of Ahnas the greywater generated from the showers and washbasins is pumped through pipes to a storage reservoir. Then, it is treated in a second reservoir. The treated greywater  is used for irrigation of the main and the secondary courts’ grass.

The football course overview 

Tanks of the greywater recycling installed

Stop and wonder

Uses of the recycled greywater

Greywater after its proper treatment can be used for secondary uses such as the toilet flushing, car washing, watering of urban green areas, sports field irrigation and, for groundwater recharge under controlled conditions. It can be used for watering tree plantation i.e. orange, lemon trees, etc. given that it meets the defined criteria and conditions. Nevertheless, it is not allowed to be used for contact with the human body nor for watering vegetables (tomatoes, cabbages, etc). When used for irrigation it is forbidden to use sprinklers because of the risk to come in contact with the human body. Drip  irrigation or underground channels are recommended instead.

People’s attitudes towards treated greywater use

In general people tend to accept or reject the use of recycled greywater depending on the type of use. It is relatively well accepted to use greywater in watering golf courses and parks and in industry (for cooling purposes). But people are more reluctant to use it at home. Actually, the level of acceptance is influenced by the degree of contact with it: people tend to accept it when contact is minimal (for toilet flushing) and are less ready to use it for watering. Other studies show that users prefer to reuse their own greywater rather than that of communal recycling schemes.

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