Water footprint

•      Water footprint is the amount of water used to produce each of the goods and services we consume.

Importance of estimation of water footprint

Water has become scarce resource in many region.

·        The extraction rate of ground water has exceeded the rate of natural replenishing.

·        Water has no equal distribution throughout the world.

·        Significant fraction of available water is not suitable for human consumption due to the pollution.

·        Most of the area of the world do not receive sufficient rain or seasonal rain pattern has been changed as results of global climate change.

·        Identify the water intensive products, services, behaviors and input into production.

·        Help to reduce the water consumption or pollution through a production chain.

·        Manufacturing goods at one place have impacts on water basin anywhere else.

The difference between traditional water withdrawal indicator and water footprint

·        The water withdrawal indicator considers the non-consumptive water use too. Non consumptive water use refers the return water flow. The blue water footprint of direct water footprint of a product is considered as the return flow. The water footprint only take consumptive water use into account.

·        Water withdrawal indicator only measures the blue water footprint component but water footprint involves the measurement of all three components (Blue water footprint, green water footprint and gray water footprint).

·        Water withdrawal indicator refers to only the direct water use but the water footprint considers both direct and indirect water use.

The water footprint of a product is the volume of freshwater used to produce the product, measured over the various steps of the production chain. The water use is taken as the measure of the water volumes of consumed of polluted. Water evaporated or incorporated to products is considered as the water consumption. Thereby that water may be no longer able to be used in its original form or reuse readily.  The water footprint of a product is estimated as the volume of fresh water used per unit of product.

The water footprint is often divided into three components.

Green water footprint: It is the volume of water consumed from the global green water resources (rainwater stored in the form of soil moisture).

Blue water footprint: It is the total volume of freshwater consumed from the global blue water resources (surface water and ground water).

Gray water footprint: It is the volume of freshwater that is needed to dilute the pollutants load to meet the existing national water quality standards.

Virtual-water chain

    The ‘virtual-water content’ of a product (good or service) is considered as the volume of fresh water used to produce the product, over all steps of the production chain.

The water used to produce a product is considered as the virtual water except the water contained in the product. The virtual-water content of a product is significant compare to the real water content of most products. The water use at a particular step is considered as the direct water use.

Water footprint of a business

It is the measure of total volume of fresh water directly or indirectly incorporated use to run or support a business.

Use of water in the business

It is incorporated as an ingredient into products or used as a solvent. After production process, raw water is subjected to pollution and released as effluents which threat the wellbeing of the aquatic ecosystems.

Problems associated with mismanagement of waste water

§  Disrupt the company reputation

§  Pay for the pollution caused by particular industry (Polluter pay principle) to the nearby water systems

§  Subject to strict regulatory control if the company does not take appropriate action to manage the incidents regarding sudden failure of the waste water management

§  Insufficient availability of freshwater for conducting the operations

 Water footprint of a business is comprised of two components including direct water use and indirect water use. Direct water use refers to the operational water print. Indirect water use refers to the supply chain water footprint.

The operational water footprint is the water consumption and pollution related to the operations within the business. The operational water footprints is again divided into two components as operational water footprint directly associated with production of products and overhead operational water footprint. A considerable fraction of water returns to blue water resources after waste water treatment process therefore only consumptive water use of the blue water footprint is considered in the estimation of water footprint of production of products. The overhead operational water footprint is the water consumption and pollution related to general water using activities including water use in bathroom and kitchen, watering the garden and washing the worker’s clothes within the business.

 The supply chain water footprint is the volume of freshwater consumed or polluted to produce all the inputs of production of the business. Thereby water footprint of one business can be overlapped with water footprint of another business through the supply chain. The supply chain water footprint is also again divided into water footprint related to products inputs and overhead supply chain water footprint. Overhead supply-chain water footprint is the volume of water consumed or polluted due to the materials and energy for general use including cars, trucks, fuels, electricity.

Supply chain water footprint is larger than operational water footprint of many business which does not have own agricultural activities to produce their input since production of feed for animals requires much water than operating the processing industry including cleaning, washing equipment and pollution . The supply chain water footprint is dominated by green water while the operational water footprint is dominated by blue and gray water.

Water footprint of a person

The water footprint of a person is the total volume of freshwater consume or polluted to produce all the good and services. According to the recent researches, nearly 4 % of the water footprint of humanity relates to water use at home (Hoekstra and Mekonnen 2012).

Water footprint of a consumer is divided into two components including direct use and indirect use. Direct use refers to the water use at home. It includes the drinking, bathing, cooking and washing at home. Number water units consumed per month is used to calculate the direct water use. The water footprint regarding consumed goods and services is considered as the indirect water use. Multiplication of number unit consumed from each good and services by their respective water footprint is summed to estimate the indirect water use.

Reduction of water footprint:

Industry: water meters should be installed to monitor the water use. Water audits should be conducted to identify the leaks and fix them as soon as possible. Raw materials with low water footprint should be used for manufacturing goods and services rather than raw materials with intensive water footprint. As an example, sugar cane cultivation requires more water than beet cultivation. Water results from the evaporation from beet can be used for the operations within the sugar manufacturing industries. Thereby it eliminates total water requirements from blue water resources including ground water and surface water. Therefore use of beet as raw materials can reduce the total water footprint along the both operational and supply chain of sugar manufacturing industry. Rain water harvesting system can be installed to store the rain water. These rainwater can be incorporated into boilers, condensers, cleaning the factory floors and flushing the toilets to reduce the use of portable water within the factories. Waste water treatment plant should be constructed or existing waste water treatment plant should be further improved to enhance the quality of the treated water. These treated water can be used for cleaning purposes and boilers of the factories. The pressure of the water distribution system can be reduced to decrease the volume of water delivered for particular purpose. Regular taps should be replaced by sensor taps to prevent leakages. Dual flush system should be installed for the toilets system rather water intensive single flush system. Dual flush system has separate flushing for feces with high water requirement and urine with less water requirement. The volume of the tank of toilet tank can be reduced by using a displacement device such as bottle filled with water.

Personal: Good and services with large water footprint should be purchased rather than goods and services with small water footprint. Products associated with beef meet requires more water than products associated with chicken meet because the cultivation of feed for cattle often consumes more water. Water saving techniques including sensor taps, faucet aerators, dual flushing systems and rain water harvesting systems can be implemented. The top loading washers can be replaced with less water consuming front-loading clothes washers. Leaks should be identified and fixed. Spills should be avoided as much as possible. Although people can reduce the negative impacts related to direct water use, it is difficult to reduce the negative consequences of indirect water footprint.