Practical water saving

This week our third study article for the 2018 Thrive EnviroQuiz competition, written by sustainability advocate ANNABEL RYDER, explores practical ways to reduce daily water use.

Included are 10 questions that may be asked during the inter-schools quiz on Friday September 7.

The previous article explored different types of water and how to re-think water usage, and this week’s article looks at how water usage behaviours must change over the short to medium to longer term, to help reduce daily consumption to within and even below the current Level 6B allowance of 50 litres a person a day.

With dam levels currently at just 20% (of which the last 10% is unusable) and the upward creep of total daily water usage to some 100 million litres daily above the City’s 450 Mn litre daily target, it is more important than ever that during this winter, everyone saves more water each day.

The threat of Day Zero next summer remains very real, given April’s rainfall patterns, and ensuring we have sufficient water supply to last through to April-May 2019 is critically dependent on everyone’s daily actions to save even more water, wherever they are.

The City of Cape Town’s infographic gives an indication as to how a household might use its current water allowance of 50 litres a person a day.

It also gives ideas as to how to reduce water usage by making different choices, for example using waterless hand gel as opposed to washing hands.

Remember, this 50 litres daily allowance is total water usage, wherever you are, at home, work, and school or on holiday. Thinking of the different types of water, it is very clear that there are certain activities that have to use the municipal SANS 241 standard tap water in order to be safe and hygienic.

Ranked in some indicative order of being able to “survive”, these are drinking (3L), cooking (1L), teeth and hands (2L) and dish-washing (9L), and of course pets (1L) if you have any. So some 16 litres of the daily 50L allowance must come from SANS 241 standard tap water. But that still leaves some 34 litres a person a day, with scope to save even more water.

However, given that “water-scarcity” is the new normal, we all need to start exploring more sustainable, longer-term ways to save water and to store and re-use water in our homes, schools, offices and shopping malls.

Be curious – it is time to re-think some of our everyday assumptions about water availability and water uses, and the systems we have in place to manage water.

Waste is a concept that until recently hasn’t really been applied to water – we tend to think of waste as recycling versus landfill waste. Now think about toilet flushing, critical for health and hygiene – do you really want to use almost 20%, or 9L of your 50L daily allowance on flushing?

Start immediately (if you haven’t already) using captured grey water to bucket flush the toilet by catching “used” water from the shower and basins. And start researching water-less toilet systems, such as compost toilets, that with a little effort, will provide rich compost – or humanure – for your garden.

There is scope for some really great innovation to re-design toilets, basins, showers, and how water and waste flows between them. For example, for completely waterless body cleaning, an innovative dry hygiene solution called DryBath®cleaning gel, was invented by a young South African entrepreneur, Ludwick Marishane.

Award-winning research at UCT is exploring the value of urine, and how this “liquid gold” which contains high concentrations of nitrogen, phosphorus and potassium, can be recycled and converted into fertilisers and even bricks. Meanwhile, you can dilute your pee with shower water in ratio three parts water to one part urine, to use as liquid fertiliser in your garden, and you can make your own water saving 1L shower from an old PET bottle.

Longer term changes in our daily behaviours may require some retrofitting of for example, bathrooms, water pipes in and out of our homes and provision for rainwater collection. But this need not be expensive and over time, it will pay for itself as well as having more localised water security.

Did you know that for every 1mm rain on a flat 1m² roof space, you will collect 1 litre of water?

For example, the average double garage is 40m²; meaning that every 1mm of rain will yield 40 litres of water which can easily be collected using inexpensive plastic tubing and attaching this to the gutter or downpipe with a zip tie.

Install rain chains, collect rainwater in tanks, lead it via plastic tubing to fill up your swimming pool, use it to bucket flush the toilet, to water lawns and gardens, for composting, or as pets / livestock drinking water, rather than letting it disappear down the storm-water drain, wasted.

Become a Water Warrior (not a Worrier) – and please don’t waste this winter’s rainwater. Remember, no water should be allowed to leave our homes after a single-use. Reduce, reuse, recycle.

In the next article we will look at household waste and how to reduce and reuse our waste.

For further reading on a cheap rainwater harvesting system visit https://www.countrylife.co.za/leisure/arts-crafts/diy-rainwater-harvesting

To make your own 1L shower using an old PET bottle visit http://capetownshower.org/diy-instructions.html

* Questions

1. At what percentage of total storage capacity are local dam levels?

2. How many litres per day of fresh SANS241 water is assumed use for toilet flushing?

3. What is the waterless toilet system mentioned?

4. Name three ways rainwater can be harvested.

5. What is the by-product of a compost toilet?

6. How can single use of water be eradicated from our daily lives?

7. How much rainwater would a flat 50 m2 roof produce from 10mm rain?

8. Name two examples of waterless products mentioned.

9. Which valuable elements are naturally found in urine?

10. Name three uses for collected rainwater.

Answers

l Answers
1. 20%
2. 9 litres (almost 20% of 50L allowance)
3. Compost toilet
4. Rain chains, rain tanks, plastic tubing, buckets
5. Humanure – or compost for the garden
6. By capturing and reusing water before throwing it “away” e.g. greywater
7. 500 Litres
8. Compost toilet, waterless dry hygiene solution DryBath, waterless hand gel
9. Nitrogen, phosphorus and potassium (basis of NPK fertilisers)
10. Flushing toilets, filling washing machine, watering lawns and gardens, filling up pool, composting, water for pets and livestock, water indoor plants, washing vehicles, fire protection