Monday 9 May 2022: Water Neutrality
What is water neutrality?
Although I have never heard the term before, I imagine that it is analogous to 'carbon neutrality', that is, a situation in which overall water usage is not greater than the rate at which the natural environment can replenish it, with the consequence that rivers return to full natural flow, water tables stop sinking, and aquifers are no longer being depleted. I imagine that water neutrality requires reduction in water consumption, and the cleaning and re-use of grey water.
In order to achieve water neutrality in a home or flat, solutions need to be installed or built in:
- What water saving solutions are you aware of? (please specify if for a home or flat)
- What do you think motivates customers like yourself to install water-saving solutions such as these in their homes? Why?
- What are the barriers? Why?
There are devices that can be (retro-)fitted, such as tap aerators and toilet cistern water displacement devices. There are devices that can be fitted at refurbishment, such as dual flush toilet cisterns and aerating power showers. There are maintenance programmes to ensure that taps are not dripping and toilet cisterns not leaking. There are water storage containers (such as water butts) in which to store rainwater and grey water for use, say, in the garden. There are customer education programmes to encourage customers to think more carefully about how they are using water. There are smart water meters that allow customers to monitor their water usage on a daily basis in order to understand how they are using water, with a view to reducing unnecessary water use.
My personal motivation for water use reduction is due to my long-standing commitment to reducing my impact on the environment as a whole. I imagine that this commitment applies to some people. I am also motivated by shame that I was responsible for the wasting of nearly a million litres of water, although I was ignorant of the burst mains pipe until the water started to make its way to the ground surface. I am partly motivated by a need to reduce my bills because I have no income.
In my view, the greatest barrier to customers reducing their water use is neither knowing, nor really understanding, how much water they are using, and that the effect, as a society, on the natural environment as a result of overuse is significantly damaging. Smart water meters would go some way to countering this ignorance.
What is meant by 'water re-use'?
Water re-use generally refers to the capture, treatment (if required) and use of alternative water supplies for non-potable purposes. It includes rainwater harvesting, greywater (typically the used water from baths, showers and hand basins) and black water (sewage) recycling and any other type of water recycling or reuse.
What is rainwater harvesting?
The ancient practice of rainwater harvesting (RWH) can be traced back at least 4000 years. Rainwater harvesting is the term used to describe the collection of rainwater that falls onto surfaces, such as roofs, and is stored for future use.
Is rainwater harvesting the same as storm water or surface water harvesting?
Some people use the term RWH to include both the capture of rainfall directly from roof areas as well as the capture and reuse of surface water runoff (also known as storm water or surface water harvesting). These two types of rainwater harvesting may vary quite a bit in terms of water quality, scale, application, cost etc. depending if it is rainwater from roof areas only or a surface water harvesting system.
What is grey water recycling?
Grey water, especially where it is limited to that from baths, showers and washbasins (sometimes termed ‘light grey water’) can be considered high volume, low strength wastewater with high potential for reuse. Most existing buildings plumbing directs all wastewater to the sewer. Separating out grey water from the more polluted wastewaters (e.g. from toilets, often termed ‘black water’) means it can be treated and used as an alternative source of water for non-potable purposes. Generally, grey water recycling (GWR) systems can supply water for toilet flushing, irrigation, outside water use and laundry.
What is black water recycling?
Black water is any wastewater that is contaminated with water discharged from a toilet, so this can and usually does contain grey water. It can also be used to describe wastewater, process or cooling water from industry. Blackwater recycling requires treatment before it can be reused. This usually involves aerobic screening, biological treatment, ultrafiltration, ultraviolet disinfection, TDS (total dissolved solids) and nutrient removal and chlorination.
After reading the definition of rainwater harvesting, what do you think are the pros and cons of this water-saving solution? Why?
Yes, please. I already harvest what I can, but it is the proverbial drop in the ocean in relation to my needs. The pros are obvious: quantities of water that fall from the sky that does not have to travel though the water supply system with all the attendant costs. The principal cost is that of creating the storage capacity. I am already highly motivated towards rainwater harvesting. However, harvesting the water is pointless if I have nowhere to store it. What I have is 1,000 litres of storage. What I require is a means to store up to 500,000 litres of winter rainfall for use during the now-annual spring and summer droughts.
After reading the definition of grey water recycling, what do you think are the pros and cons of this water-saving solution? Why?
Again, yes, please. I manually save bathwater, and use it for toilet flushing. Vegetable and fruit washing water gets used to water the greenhouse plants. Washing up water is also used for toilet flushing. I would love to be able to divert all grey water into proper storage (we currently use lots of buckets), but I not only do I need pipework from, say, the showers (and the bath), but again, there is the major issue of storage. This latter is the principal barrier to making fuller use of grey water (say, from showers).
Whilst I have no reservations about using grey water appropriately, I have no doubt that there would need to be quite a lot of customer education in order to encourage ordinary (uncommitted) people to make use of it.
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Rank the following preferences: (my ranking shown)
1. Reducing environmental impact by decreasing the amount of water abstracted from rivers and groundwater sources.
2. Reducing the amount of water going into the sewage network by using less water, recycling grey water and rainwater harvesting.
3. Saving water – around 112,000 litres could be saved every year for each water neutral home built.
4. Improving resilience for the future by minimising the additional pressure on water resources and networks.
5. Saving money – annual savings on water and energy bills of around £44 per home can be achieved from reducing water demand in the home to 85 litres per person per day (for those on a meter).
6. Enabling future housing growth in water scarce areas by reducing the impact of new homes and buildings on the water environment, and preventing water resources being a constraint to growth.
Please explain your ranking
- What was 1st place and why does this appeal the most to you?
- What was last place and why does this not appeal as much?
My first place ranking is about protecting the natural environment. Human hubris is bringing the world to the edge of disaster, and both individually and corporately we need to centre-stage the natural environment.
To be fair, the first six statements are all important. However, I reserved for last place prioritising economic development. As a world we need to be stepping back from economic development, as we are already using annually the replenishable resources of 1.6 planets (Earth overshoot). Here in the UK, (the sixth largest economy in the world, we are using resources at a very much faster rate than the world average, so the stepping back has to be very much greater than the world average. There is a desperate need for new housing, but this does not have to be as greenfield developments. The most pressing housing need is for one and two-bedroom social housing, which would be much more environmentally-sustainable if built as flats on brownfield sites in cities and large towns (concentration of services, availability of public transport) as low-rise multiple-occupancy buildings. I should prefer to see no new greenfield developments, and allow the term 'water neutrality' to be applied more widely to cities, towns and villages.
Thinking about grey water systems. These require specialist plumbing and storage space. The unit requires space equating to the size of an American style double fridge. If you were buying a newly built house and knew that the system could save you around £44 per year on your water and energy bills, what would you be prepared to trade-off/ give up in order to make space? Please select from the list below and explain why in the comment box
I’d give up having a patio
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