Water is Life: Conserve, Recycle & Innovate

About the author:

Madan Arora Ph.D., P.E., BCEE is a technical director at Parsons. Arora can be reached at [email protected].

Why Water is Life

Did you know that water is needed in almost everything we use, we do, and we eat? Table 1 shows a summary of how much water we use every day for food and products we use in our homes and daily lives without even thinking for a moment how much water is needed to make these products.

Did you also know that the human body contains 70 to 75% of water by weight? So a person weighing 160 pounds contains about 115 pounds of water. This is simply mind boggling. To put it mildly, we cannot live without water — a lot of water.

Water is life.

So philosophically, not buying and consuming too much – clothes, furniture, cars, toys, i-phones, big luxury homes, unneeded appliances — will save a lot of water. Recycle and donate these to charities so that, in the big picture, water consumption is reduced. Overconsumption reduces our supplies of water.

It is a moral imperative that we, as a society, should discard the culture of excessive consumerism and waste since it needlessly consumes large quantities of water which is worth conserving.

This article presents three important ways of water management:

• The conservation of water;
• Water reuse and recycling; and
• Water and wastewater treatment innovation.

The Conservation of Water

Water conservation is an important yet practical and simple-to-implement way to ensure that our water supplies last longer at home, in our neighborhoods, in our cities and villages, in our states and countries and by extension on our planet as a whole.

Below are many practical ways to conserve water that we can take in our everyday life in a handful of categories.

Establish Good Habits With Daily Chores

• Teach your kids how to conserve water and help them do it. Rewards are a great incentive.
• When washing clothes, make sure to wash full loads of laundry. This same rule applies when using the dishwasher, keep it full.
• Match the water fill to the appropriate size of laundry that you are doing.
• Use the broom instead of hose to clean your driveways or sidewalks.
• Teach your kids to turn the faucets off tightly after each use.

Think About Washing Efficiencies

• When washing your dishes (without the dishwasher) do not leave the water running to rinse.
• Try to use fewer plates and cups to reduce the amount of water needed for washing.
• Fill the sink with soapy water in the sink when washing dishes by hand. Quickly rinse under a slow-moving stream from the faucet.
• Use energy-efficient washing machine. It saves up to 18 gallons of water per load.
• Use the commercial car wash to wash your vehicle. A lot of water is wasted doing it at home.

Lawn & Yard Maintenance Water Use

• Plant your garden in the spring since water requirement is reduced.
• Minimize the amount of time spent watering the lawn. Ensure you are watering it only when needed and do not overwater it.
• When watering the lawn ensure that the sprinkler system is set the right way so you are not watering the gutters and driveways. Make every drop count.
• Harvest rainwater if allowed in your area. Store it and use it when needed.
• Use brooms or other tools to clean gutters instead of the water hose.
• Use a layer of mulch around your plants so they retain moisture for a longer time period.
• Check your hoses and pipes for leaks, cracks, and other damage.
• If you have a small lawn, try to water it by hand rather than using sprinklers. This way you have more control over the amount of water used.
• Install covers on pools to avoid loss of water by evaporation.
• Water your lawn during early parts of the day.

Hygiene & Food Efficiencies

• Turn the water off when brushing your teeth or washing your hair.
• Do not use water to defrost foods. Although many people use this method, it requires a lot of water to do so.
• Take shorter showers.
• Stop using extra water when you flush by avoiding placing anything in the toilet. This includes tissue and cigarette butts.
• Use the right size pans when cooking.
• Don’t let water go down the drain while you are waiting for the temperature to adjust when taking a bath.

Appliance Water Use

• Purchase water-efficient products and appliances for your home. This includes dishwashers, sink systems, bathtubs and more.
• Check for leaks. This includes the toilet and the sinks in the home.
• Recycle water used in water fountains and other water decorations.
• Consider purchasing a dual-flush toilet. These technology-savvy toilets are great to promote water conservation.
• Install water saving devices such as low-flow shower heads on all showers and faucet aerators on all faucets to reduce water use.
• Read your house water readings at regular intervals when no water is being used and check for hidden water leaks.
• Don’t use your toilet as a trash can. Every time you flush your toilet, you use up to 9 to 12 liters of water.

Water Reuse & Recycling Treatment Stages

Did you know that wastewater is 99.9 to 99.95% water? It is only the remaining 0.05 to 0.1% (about 500 to 1000 mg/L) that is composed of impurities originating from industries or from human consumption of water. Wastewater treatment and recycling, therefore, involves removing only these impurities. Why then should we not reuse and recycle water?

The population on our planet is projected to increase to more than 9 billion from the current 7.5 billion by the year 2040. In addition, standards of living are continually increasing all over the globe, which are further stressing our water resources. However, water quantities available for use are constant and always have been since the dawn of time. Water recycling is a resource which therefore must be tapped to meet the continually growing demand of water. This serves as another reason why we should reuse and recycle water. 

There are five stages or levels of wastewater treatment, some or all of them are necessary before water can be reused and recycled. How many stages should be employed before reuse depends upon the type of intended reuse. The purpose and level of treatment in all cases is the protection of public health. For example, if the water is going to be reused for growing alfalfa intended for animal feed, the requirements will be less stringent than if it is to be used to grow edible crops like tomatoes and lettuce. Similarly, if the intended use is for irrigation of golf courses at night time, the requirements would be less stringent than if the intended use is for irrigation of school playgrounds used by children. Reuse for drinking purposes — direct potable reuse (DPR) or indirect potable reuse (IPR) applications — would require the highest quality of recycled water and all five stages of treatment. In addition very aggressive monitoring, redundancy and reliability in design and operation would be required, and reuse applications in between these two extremes — of which there are numerous — will similarly require fewer stages of treatment.

These five stages of treatment (see Figure 1) schematically are:

1. Preliminary treatment;
2. Primary treatment;
3. Secondary treatment;
4. Tertiary treatment; and
5. Advanced treatment.