Understanding Wastewater Recycling – Grey Water
The theme of this year’s World Water Week is ‘Water and Waste – Reduce and Reuse’; both key actions that are at the forefront of saving our water resources. We want to draw attention to wastewater recycling, as it is a crucial process and if managed correctly, can save freshwater resources and limit our overall public demand. Recycling water reduces water usage; an obvious but very paramount idea. Water serves many areas of our lives, including flushing our toilets and irrigating our gardens; actions that do not need the same level of purity to our drinking water.
Grey water (or greywater) is the wastewater from our laundry, showers/bath drains and sinks. It gets washed down our drains and wasted by adding to sewage and combining with black water (the water from our toilets). It is a resource that can be recycled, if stored and potentially treated correctly. The system itself, collects all water from non-toilet plumbing sources and flows into a storage tank, or can be siphoned directly, depending on the method used. It would then be treated, either in the tank itself if using chemicals, or filtered naturally based on different sustainable designs. This would finally be discharged back into the ground or pumped back into the toilet, depending on the system installed. There are many different types of systems and treatments, scaling from direct/natural methods to fully automated installations.
If the grey water is treated, it can be used for flushing the toilet and watering plants (including food-producing plants). Untreated grey water is suggested only for irrigation of non-food producing plants and should generally be used directly or quickly to avoid bacteria feeding on organic matter.
There are many benefits for using grey water to irrigate plants regarding nutritional value. This is due to the small quantities of compost present in the water itself. Another benefit of reusing grey water is reducing chemical usage as it encourages users to be more mindful with their own systems and the overall quality of their own grey water. As well as this, it helps recharge our ground water supplies, reduces the amount of wastewater entering the sewage system and saves fresh water being used when recycled water could be used as an alternative.
Managing grey water can be less environmentally friendly if the system requires a great amount of chemical treatment. However, there are ways to treat the water naturally, including using a sand filter method and wetland process. As well as this, using a direct system would require little to no treatment. Other issues that have been suggested with having a grey water system include the cost of installing a full system and the energy usage of the pump’s operation. However simple systems such as directly siphoning the water are cost-effective and easy to set up, requiring little maintenance.
It has also been suggested that using a grey water system is less cost effective than simply reducing your individual water consumption. Whilst reducing your water consumption is a key component, installing a simple grey water system and combining these methods lays a sustainable foundation and can create a greater impact.
Reduce and reuse. These are crucial actions that we need to implement to recharge and sustain our water levels effectively and immediately.