This presentation proposes a new method to optimally utilize the water supplied to domestic households in such a manner that both water and energy used in running the supply pumps can be conserved. The proposed "sensor based network of sub-tanks" can help to reduce the wastage of sufficient amount of water and the introduction of purifier at the inlet can save energy which is otherwise wasted in over running a corroded water pump.

1. SMART USE OF WATER
AND ENERGY IN
DOMESTIC HOUSEHOLDS
Mrinmoy Majumder, PhD

2. How water is utilized in domestic
households ?
 Washing and Cleaning
 FlushingToilets
 Bathing
 Cooking
 Gardening
“Most high-efficiency washers use only 15 to 30 gallons
(56.8 to 113.6 L) of water to wash the same amount of
clothes as older washers (29 to 45 gallons per load (109.7 to
170 L).” in USA.
In the US “Older toilets can use 3.5, 5, or even up to 7
gallons of water with every flush. Federal plumbing
standards now specify that new toilets can only use up to
1.6 gallons per flush (GPF), and there are high efficiency
toilets that use up to 1.28 GPF.”
Indian Standards : Maximum amount of water allowed to be
used by a person per day : “Bathing: 55 litres; Toilet
flushing: 30 litres; Washing of clothes: 20 litres; Washing the
house: 10 litres; Washing utensils: 10 litres; Cooking: 5
litres; Drinking: 5 litres”.
In USA, estimated use of water per person per day is about
80-100 gallons whereas in India the standard(IS 1172 ) is
135L/35.66 gallons per person but actual use varies widely.

3. Groundwater
based
Households
(GWS)
 The required amount of water is withdrawn by
electric pumps or tube wells from underground
aquifers
 Water may be “heavy and hard”
 Can be contaminated
 Presence of Iron and Fluorine sometimes
Arsenic
 Scarcity : When adjacent water table is
decreased during summer

4. Surface Water Based Households
(SWS)
Withdraws water from surface water sources
like rivers, lakes, ponds etc. with the help of
electric pumps and pipelines/canals which
brings the water from the source to consumers.
More the length of the pipelines more will be
energy utilized by the pump
May be contaminated with coliform and
algae : the concentration of the algae or
bacteria depends on the amount of
dissolved oxygen.
Presence of “Iron/Fluorine/Arsenic/Oil and
Grease/Suspended as well as dissolved
matters”

5. Consumes Municipal/Treated Water
(MS)
 Uses submersible pumps to withdraw water.
 Supplied by the municipality after treatment.
 As purified, minimum chance of contamination.
 Reduced amount of heavy metal concentration.
 Minor amount of dissolved and/or suspended solids.
 Increased amount of dissolved oxygen.
 Free of Oil and Grease.
 Expensive.
 Infrequently supplied in some places.
 Sometimes taste and colour of the supplied water becomes untenable.
 Amount of chlorine may be more compared to the surface or ground water sources.

6. Consumes Water from Surface Water
Treatment Plant(SWTP)
 House hold is fed by the treated water from SWTP .
 May have greater amount of chlorine.
 Turbidity may be high which make the transparency low.
 Chance of contamination during supply and in the supply lines.
 Dissolved oxygen will be high which may effect the taste of the water.
 Expensive due to the treatment process, so wastage of water will effect
the bill paid by the consumer.

7. Consumes Water from Waste Water
Treatment Plant(WWTP)
 The house hold is fed by treated water from WWTP.
 Such water have a higher chance of contamination compared to other sources
 Probability of the presence of chemical compounds will be more.
 Dissolved oxygen may not be as high as the water received from other sources
which may effect the taste and quality of the water
 Presence of faecal coliform and bacteria will be more compared to the supply
received from the SWTP
 Highly Expensive, more than SWTP, for the advanced treatment process adopted
for purification of the waste water, so wastage of water will effect the bill paid by
the consumer

8. Consumes Water from Treated Rain
Water
 Water is withdrawn from the rain water harvesting tank or recharge pits.
 Contamination chance is high and depend on the tank and supply lines used.
 Chance of contamination during supply and in the supply lines.
 Suspended solids and turbidity will be high compared to SWTP but lower
compared to WWTP.
 Cheap but quality is .doubtful and will depend upon the treatment
mechanism adopted by the system.
 Quantity that can be treated and supplied for consumption is uncertain and
depend upon the amount and frequency of rainfall along with the volume of
the storage tank.

9. Contaminants
 SWTP
 Aluminium, Arsenic, Asbestos,
 Barium, Beryllium, Boron,
 Cadmium, Cobalt, Copper, Cyanides,
 Iron
 Lead, Mercury
 Nickel, Nitrogen
 Selenium, Silver.
 WWTP
 Non-regulated trace organic ECs including pharmaceuticals
 Illicit drugs
 Personal care products
 SWS
 sludge, brine disposal from the petroleum industry, mine wastes, deep-well disposal of liquid wastes, animal feedlot wastes, ...
 GWS
 Nitrates, Pharmaceuticals & Personal Care Products

10. Problems
 Physical : Scarcity of Water : Most of the water supplied to a household is
actually wasted. The practice of recycling is not widely observed and also
avoided due to misconceptions related to the quality of the water. Sometimes
due to head difference between the source and consumers water flow gets
reversed and phenomena like water hammering occurs which have the
capacity to damage the pipelines.
 Chemical : Poor quality of water. The concentration of Dissolved Oxygen
depend upon the presence of dissolved and suspended solids specially the bio-
degradable products. As a result the taste and visibility of the supplied water
get affected most of the times
 Biological : The supplied water is often contaminated by organic wastes
released from other households which leads to the presence of various types
of microorganism. Tests show that contaminants affect the health of the
consumers and many time is the sole reason for health related disasters.

11. Major Problem
 Scarcity of Water : Both amount and frequency of
supply is unreliable and irregular
 Degradation in the quality of supplied water
 Another problem which is an indirect problem of
the previous two problems is :
 Wastage of electrical energy in pumping
 To maintain supply, water has to be pumped
frequently
 Degraded quality of water can corrode the internal
materials of the pump(if submerged)
 Which will lead to a reduction in pumping
efficiency
Solution
 Water has to be conserved at least at
the side of the consumers
 Different types of water filter can be
used to treat the supplied water.

12. Pattern of Consumption
Time of Use Type of Use

13. Time
 Frequent Use : The water consumption is frequent and practiced at an regular
interval.
 Example :
 Washing and Cleaning
 Flushing Toilets
 Bathing
 Cooking
 Infrequent Use : The consumption of water is irregular. It happens at an
interval of one or more days.
 Example:
 Water used in Gardening

14. Type
 Drinking : For consumption by the residents of the household
 Washing : For washing the clothes
 Cleaning : For cleaning the car/floor/utensil etc.
 Cooking : For cooking the foods
 Gardening : For watering the garden
 Other uses

15. Location of Water Used within a
Household
Washing and Cleaning, Bathing ,Flushing Toilets etc.Bathrooms
CookingKitchens
GardeningGarden Tank
Multi - Purpose
Ceiling or Ground
water Tank
Other

16. Idea to conserve water :
 Use a holding tank in every locations where water is used.
 The volume of the tank must equal to 1.5 times the
amount of water (per day) required at that location.
 A sensor to detect water level can be placed there to
measure the water level of the tank and a minimum depth
can be earmarked so that once the level crosses this mark
the tank will be refilled

17. Idea to conserve water :
(CONTD.)
 The tanks will be attached to the main supply and from the tank water may
be distributed to the taps, toilets etc. of that location only.
 The replenishment of the tank may also be monitored and some cutting off
threshold may be implemented to prevent over use.
 During the lean period of water supply the tank will conserve the water

18. Idea to conserve water contd. :
 A tank is generally located in the roof top in a house from where the water is supplied to
each of the location of water use.
 All the sub-tanks mentioned previously can be connected to this main tank .
 A level detecting sensor can be used here also, for automatic replenishment of tank and
also to prevent over withdrawal of water, if a cutting off threshold is implemented in this
aspect.
 Once the threshold is crossed, further replenishment of the tank will be prevented if not
manually overridden or if the duration of refill is over.
 The volume of the tank must also be equal to the 1.5 times the total volume of all the sub-
tanks.
 The 0.5 times is kept as a free body or buffer within which the water use generally varies
even during the time of uncertainty. The previous data for water use can be utilized to
detect the amount of water required by the household(Standard in India is 135l per person
per day).
 This type of arrangement can save sufficient amount of water which is generally flushed
out after use.
 Here the use of water is also monitored by the implementation of water level detectors.
This type of monitoring help to avoid unnecessary use of water and conserve the supplied
water for later use.

19. What about quality of water ?
 Instead of using a water purification unit in the kitchen or bathrooms the same may be
installed at the outlet of the main tank.
 This will ensure that the water will be first treated and then disbursed to different
location of water use.
 But the pumps are mainly effected from direct contact of the supplied water.

20. What about quality of water ?
(CONTD.)
 That is why, if a filtration unit is used at the inlet nozzle through which water
is supplied to a household by the municipality, then the treated water will
only reach the pumping arrangement and as it will be devoid of corrosive
agents, it will not rust the pump and its internal materials.
 The same arrangement may be implemented in the inlet from the well or
outlet of a rain water harvesting tank if the water is taken from groundwater
or surface water sources or from the rain water tank.
 The treatment unit at the inlet may not be highly sophisticated but it must
ensure the removal or reduction of the concentration of heavy metals,
dissolved and suspended solids.

21. SUBTANK
SUPPLYTANK
TANK
TREATMENT
UNIT
PIPELINE
SCHEMATIC DIAGRAM OF THE ARRANGEMENT FOR SMART USE OF WATER AND
ENERGY
Water
level
indicatorElectric
Pump

22. What s next ?
 Water is conserved at a level required to maintain the disbursement of supply
among the different location of the water use.
 As the water level is monitored the use of pump will be minimum, only
during the replenishment.
 The number of times of replenishment is also monitored. Overuse of the pump
will be prevented as a result of the monitoring.
 The water is supplied as per the need of the location of different water use.
The wastage will be minimum as water can be used only if required.
 The treatment unit at the inlet of the tank or towards the pump unit will
ensure that suspended matters and corrosive agents can be filtered before
supplying the water to the pumps.
 The economic liability of sensors and treatment unit will be much lesser
compared to the conventional arrangement of water if only the cost of pumping
and repumping is considered.

23. ACKNOWLEDGEMENTS
Data and texts were collected from the following sources for which I want to show my gratitude :
 A review on emerging contaminants in wastewaters and the environment: Current knowledge,
understudied areas and recommendations for future monitoring
 http://www.sciencedirect.com/science/article/pii/S0043135414006307
 ClothesWasher | Home WaterWorks
 www.home-water-works.org/indoor-use/clothes-washer
 Toilet | Conserve H2O - RegionalWater Providers Consortium
 www.conserveh2o.org/toilet-water-use
 How much water does an urban citizen need? by S.Vishwanath on Feb 15,2013
 http://www.thehindu.com/features/homes-and-gardens/how-much-water-does-an-urban-
citizen-need/article4393634.ece
 How much water does the average person use at home per day?
 https://water.usgs.gov/edu/qa-home-percapita.html