Definition of waste water

Water, which is in a condition, which
- is potentially hazardous, if consumed or
- is potentially incompatible to a process, if used,
is called as waste water.

How is waste water generated?

Waste water is generated
1. In flush-toilets and bathrooms
2. By washing of clothes and utensils
3. By washing of floors, vehicles, etc.
4. In industrial processes
5. By pollution of water bodies, viz. wells, lakes, rivers, streams etc.
a. Due to growth of weeds, halycinths, etc.
b. Due to discharge of waste water into the water bodies
c. Due to infestation of harmful organisms

What is the proportion of waste water generation?

More is the supply and usage of water, more is the generation of waste water.

There are Indian Standards,
IS-1172 “Code of basic requirements for water supply, drainage and sanitation” and
IS-2065 “Code of Practice for water supply in buildings”.

In these codes, one finds a stipulation about water requirements to be assessed at 1000 litres per day for an average family of 5 persons. This means water requirement as 200 litres per capita per day. This sounds to be too luxurious stipulation, considering that there are

many water-starved regions across India, where ladies of the family trek 5-6 km to the water source to get water for the entire family’s need of the day. Obviously they cannot be carrying 1000 litres across 5-6 km every day. To the other extreme is the situation in a metropolis as Mumbai. I was told by a knowledgeable person of Mumbai Municipal Corporation, that the corporation pumps some 3000 million litres of water supply per day for the 12 million population of the city. That suggests an average water supply of 250 litres per capita per day.

Direct per capita consumption of water would be at an average of 3 litres of drinking, though medicos seem to advocate about 5 litres. Per capita consumption for cooking of food would be about 0.2 litres. All the rest of water supply per capita per day would get converted into waste water. Much of the water consumed in drinking would also end up in toilet! On the whole, more the water supply, more will be the generation of waste water!

Against such diversity of availability of water supply, it should be alright to make an assessment of waste water generation of about 20 litres per capita per day for the 1200 million population of the country, i.e. 24 million cubic metres of waste water per day! This yet does not take into account, waste water generated by domestic animals, the cows, bulls, buffaloes, sheep, dogs, horses, camels, etc.

Waste Water Generation In Industrial Processes
Some industrial processes are inherently water intensive. The best example, possibly is of paper-making. In fact, one can say that making paper means putting in lot of water to make pulp and extracting all of that water to make paper from pulp. Amount of water required is not only dependent on the consistency required of the pulp, but also upon what consistency is pumpable by paper stock pumps. A pump, which can pump pulp of 8% consistency implies that the pulp will have 8% paper stock and 92% water! All that 92% water becomes waste water!

Another example is of sugar making. Sugar cane is itself a crop, which needs lot of water. Water is needed in sugar-making at three stages.
1. adding lime to sugar-cane juice
2. generating steam to boil the mixture
3. fluidising the molasses for transport and disposal
Much of the water of stages 1 and 2 would get evaporated. Stage 3 is substantially of the nature of waste water.

Beverages industry is inherently water-intensive. Again, what has to go into the beverage has to be potable and pure. Water purification by a process like Reverse Osmosis has an output to input ratio of the order of 3:7, meaning, there will be a reject stream of the order of 70%. Even with recycling of the reject stream, significant amount will yet become waste water. The bottling section especially the bottles from sales-returns will need cleaning and disinfection. This process will generate lot of waste water. Canned beverages seem to be the better option from the point of reducing the generation of waste water. But cans become solid waste – waste becoming unavoidable!

Factors Influencing Growth of Market for Waste Water Pumping

1. Urbanisation and change in living styles
2. Governmental interventions towards improving public health and sanitation environment, e.g. Ganga Action Plan
3. Growth in water-intensive industries
4. Increasingly effective implementation of environment control regulations

It is seen that the trends on all the four factors are not only positive, but growing at a fast pace.

Census figures of 1991 showed that there were 20 cities across India, with population in each city being in excess of 1 million, these cities together accounting for a population of about 80 million. As per 2001 census, the number of cities became 24 and together population became 120 million. (Ref. - http://www.mapsofindia.com/census/index.html ) The highly aggravated pressures on the public health and sanitation infrastructures due to such rapid urbanisation definitely become cause for concern.

Flush toilets were not as common in Indian villages. But now, most villages are themselves getting ‘urbanised’ as far as the style of living is concerned. TVs, phones and mobile phones, computers and internet-access have reached nook and corner of the country. This fast-paced growth in communications-networking has almost nullified the gap

between urban and rural life. Flush toilets in place of open air or ‘on-site’ excretion inherently means increase in generation of waste water.

Maybe, emergence of newer and stranger epidemics like dengue and chicken-bunia can all be related to such rampant urbanisation and change in life-styles. One fears that these, viz. urbanisation and change in life-styles will always outpace the growth in infrastructure, especially that needed for effective transport, treatment and disposal of waste water.

Growth in Industrial / Manufacturing Sector

Indian economy has registered an impressive 8% growth and the trend is forecast to be positive and sustainable in coming years. The overall growth of 8% is much abetted by more impressive growth in industrial and manufacturing sector.

There has been a general impression that growth in foreign exchange reserves has had significant contribution from the services sector, specifically due to the forays in Information Technology. But the contribution from the industrial and manufacturing sector seems to be surer, though relatively silent.

Of late, it has not been as silent either, what with M&As of Tata + Corus, Mittal + Arcelor, etc. In the field of pumps, howsoever small, there was Kirloskar + SPP merger a couple of years back.

Healthy growth in industrial sector inherently means growth in the market for waste water pumping.

Speaking statistically?

The objective of this write-up was primarily to caricature the Indian scenario in waste water pumping. Speaking statistically would entail lot of collection of data, trend-analyses, etc. It may as well need quite some assumptions and estimation, which can result in differential outputs. It was kept in mind that this write-up will stay away from any such differentials.

Scopes and trends have been very well hinted. “Samajdar ko Ishaaraa kaafee hotaa hai” Hint is enough for the intelligent!