NCERT Book Class 7 Science Chapter 13 Wastewater Story

13 Wastewater Story
All of us use water in our homes and Clean water that is fit
make it dirty. for use is unfortunately
Dirty! Are you surprised? not available to all. It has
Rich in lather, mixed with oil, black– been reported that more
brown water that goes down the drains than one billion of people
from sinks, showers, toilets, laundries have no access to safe
is dirty. It is called wastewater. This drinking water. This accounts for a large
used water should not be wasted. We number of water-related diseases and
must clean it up by removing pollutants. even deaths. People even children walk
Have you ever thought where the for several kilometres to collect clean
wastewater goes and what happens to it? water. Is it not a serious matter for
human dignity?
13.1 WATER, OUR LIFELINE
The increasing scarcity of fresh-water
Clean water is a basic need of human
due to population growth, pollution,
being. Let us make a mindmap of the
industrial development,mismanagement
many uses of clean water.
and other factors. Realising the urgency
Activity 13.1 of the situation on the World Water Day,
on 22 March 2005, the General
(We have given one example of the
Assembly of the United Nations
use of clean water. You can add many
proclaimed the period 2005– 2015 as the
more.)
International Decade for action on
“Water for life”. All efforts made during
this decade aim to reduce by half the
number of people who do not have
access to safe drinking water.
Clean water There has been perceptible progress
put to use in the direction of the aim but still there
is a lot to achieve.
Cleaning of water is a process of
removing pollutants before it enters a
water body or is reused. This process of
Drinking wastewater treatment is commonly

156 SCIENCE