Water is an essential component of all things in our lives. Sadly, today access to clean water is emerging out as a source of concern in many areas of our country and across the globe. Keeping in mind the current state, there is this inevitable need to employ water efficiency strategies in building construction. There are several water conservation strategies which are very easy to implement and facilitate quick payback on the investments made. Grey water recycling is one of them, let’s understand how reusing grey water can provide utility in green building water efficiency processes.
Grey Water System
Grey water can be defined as untreated waste water which has not come into contact with water closet waste. Basically, it emanates from showers, bathtubs, bathroom wash basins, washing machines, and dishwashers. Many of us link grey water to dirty water, but while this water might look dirty it is pretty safe and even beneficial for a number of things if recycled properly. So why is grey water dirty? Well, because it contains traces of dirt, food, grease, hair, and certain household cleaning products.
Many of us also feel grey water and sewage water is same, but there is a huge difference in both in terms of the organic loading. Sewage water has a much larger organic loading as compared to grey water.
How Is It Treated
It is important to note that grey water is never going to be safe to drink, even when it is properly treated. However, the recycled grey water can be used for flushing toilets, washing clothes and irrigation purposes. There are various ways in which greywater is treated, it involves both simple and complex processes. The complexity of the purification depends largely on the purpose for which one wants to use grey water. Treatment of grey water can include:
- Settlement of solids
- Flotation and separation of lighter solids
- Aerobic or anaerobic digestion
- Chemical or UV disinfection
Where It Can Be Used
If properly treated grey water can be put into really good uses. Water for toilet flushing and laundry and irrigation of plants are some excellent examples of grey water reuse. Purified grey water can be used to water both food and non-food producing plants. The nutrients (phosphorus and nitrogen) in the grey water serve as excellent food source for the plants.
The two major benefits of grey water use are:
- Saving On Fresh Water
Recycling grey water reduces the need for fresh water. As fresh water savings increase, it further contributes in benefitting the community by dipping the demands on public water supply.
- Less Water Going Into Drains
Treating grey water reduces a considerable amount of wastewater from going into the sewers/drains. This again helps in benefitting the overall community.
Things To Consider When Thinking About A Grey Water System
1. Simple Systems Last Longer
When considering implementing a grey water system in a construction project (apartment complex or business), one must try and keep the system as simple as possible as, this is because such systems last longer, use less energy, are more cost effective and require less maintenance. Also, it eliminates the need of pumps and costly filters.
2. Design With Utmost Care
Since grey water systems can be potentially unsafe in some situations, its designing must be done with utmost care. When using grey water for irrigation purposes, the system should be set up in such a way that it delivers water below the soil surface. Also, grey water should not be applied to the edible parts of the plants as it is not safe for consumption.
3. Grey Water System Should Have Three-Way Valve
Any grey water system should contain a three-way valve, which allows wastewater to be directed back through the septic system or sewer as needed.
4. Say No To Toxic Cleaning Products
It is extremely important to avoid any toxic cleaning products in the grey water systems. Products like bleaches, chlorine-based cleansers, artificial dyes, and similar products can be extremely harmful. For cleaning purpose biodegradable products which are salt and boron free should be used.
5. Don’t store Grey Water
Grey water should not be stored for more than 24 hours as its nutrients start to break down, also it starts creating bad odors.
Grey Water System Will Become More Common In Future
Currently, India is facing serious water supply issues in many cities, hence quick measures need to be taken to conserve water or recycle the existing water. Grey water reprocessing is an excellent technology through which this problem can be majorly eased.
India’s per capita water consumption is increasing rapidly and Grey Water Recycling (GWR) systems seem to become an inevitable component in commercial and residential facilities. While such technologies are quite successful in the Western nations, India is still struggling hard with the challenges of high initial and investment costs. Affordability has by far been a contentious issue in grey water system, but more and more people are considering implementing such systems.
The term “wastewater” in many respects is a misnomer, today, the most appropriate term for this water should be “Used Water”. This is mainly because more and more people are now waking up to the benefits of grey water recycling. This blog was an alarm for those who are still sleeping, it’s time to save water by actually using it.
Curated by editor at Wienerberger India