a. Surface source:- the source containing the surface water is the surface source. Eg, Rain, River, Stream, Pond, lake, etc.
b. Ground source:- the source containing below the surface of the earth. Eg, Well (shallow & deep), Artision gallery, Spring, etc.
# Rain is the main source of water on the earth.
# The water obtained from hill spring is found in the purest form.
# Oligotrophic lake:- it gives purest waters, water pollution is less. waters are clear, transparent and nutrients poor.
# Mesotrophic lake:- a slight increase in the nutrients. lakes are green-colored and rich in aquatic plants.
# Eutrophic lake:- the lake is turbid, nutrient (Nitrates and phosphate-rich, rich in blue-green algae, coarse fish.
# Department of water supply and sewerage (DWSS) was established in 1972.
# As per the annual report DWSS Nepal of FY 2072/73, coverage of water supply and sanitation is 87% and 87.3% respectively.
Impurities:- there are three types of impurities present in water.
Water sample:- water samples from streams/rivers should be collected 40-50 cm below the surface. For physical test clean bucket and for a chemical test glass bottle of more than 2 ltr capacity is required.
1. Wholesome Water:- also known as potable water. Water that does not contain harmful impurities and does contain other salts and impurities either good for health or unharmful to health is called wholesome water.
2. Polluted Water:- Water containing undesirable substances due to which water becomes unfit for domestic uses. It may or may not contain pathogenic bacteria.
3. Contaminated Water:- It is water containing pathogenic bacteria.
4. Sterilized Water:- The water which does not contain any types of bacteria either good or harmful for health. It is normally used for medical purposes.
a. Domestic demand:- for drinking, bathing, cooking, washing, flushing, cleaning, etc. Domestic demand depends upon,
1. Domestic demand as per Indian Standard is 135 ltr/capita/day.
2. Domestic demand as per Nepali standard via stand post 45 lpcd, via private connection 65 lpcd (partially ventilated/semi-urban) and via private connection 112 lpcd (fully ventilated/urban).
b. Industrial and commercial demand:-
c. Public demand and livestock demand:-
d. Fire demand:- fire demand calculation formula based on population.
where, P = population in thousand, Q = quantity of water in ltr/minute.
Based on nature of material,
F = 3.7 x C x √A
where, F = ltr/sec, C = coff. of material (1.5 for wood, 1 for ordinary construction and 0.6 for fire resistant construction), A = total area in all storey (sq.m).
e. Leakage, losses, and thefts:- leakage occurs due to bad quality of the pipe, appurtenances, and bad workmanship. losses due to bad management and thefts are illegal tappings.
2. Hospital with attached toilet:- 500 ltr/bed.
3. Health post without toilet:- 1000 ltr/bed.
4. Health post with toilet:- 2500 – 3000 ltr/day.
6. Public institution:- 500 – 1000 ltr/day.
7. Restaurant/tea stall:- 500 – 1000 ltr/day.
8. Tourist hotel (unclassified):- 200 ltr/bed.
# minimum water demand is 65% of total demand.
Pn = P + n x a
where, Pn = population after ‘n’ decades, P = present population, a = average increase per decades.
Pn = P + n x a + n(n+1) x b/2
where, b = incremental increase per decade.
Pn = P(1 + r/100 )n
where, r = percent growth per decade. In Nepal 1.35 % as per population census 2011.
a. Water Brone Disease:- are caused due to use of contaminated or polluted water. water borne diseases have five categories.
b. Water Washed Disease:- caused due to the less utilization of water. ex, constipation, skin, trachoma, lice, itch, etc. Inside body water decrease by 1% then feel thirsty, 5% less feel fever, 10% less then feel weakness.
c. Water-Based Disease:- caused due to bacteria present in water that enters into the human body through the skin. ex, sitosovisis, parasites, etc.
d. Water Vector Disease:- caused due to bitting of bacteria (mosquito, protozoa) present in water and spreading lay eggs around the water. ex, malaria, filaria, bath fever, yellow fever, dengue, chicken guinea, etc.
|a. GI Pipe, (Identity – color one place at end):- |
#Heavy – Red,
#Medium – Blue
#Light – Yellow.
Old Modal HDPE Pipe (PE 63) & New Modal HDPE Pipe (PE 100):- Identify color throughout
|2 kg/cm2||Grey||20 m||PE-63|
|2.5 kg/cm2||Red||2nd||25 m||PE-63|
|4 kg/cm2||Blue||3rd||40 m||PE-63|
|6 kg/cm2||Green||4th||60 m||PE-63|
|10 kg/cm2||Yellow||5th||100 m||PE-63|
|4 kg/cm2||Blue||40 m||PE-100|
|6 kg/cm2||Green||60 m||PE-100|
|10 kg/cm2||Yellow||100 m||PE-100|
|12.5 kg/cm2||Purple||125 m||PE-100|
|16 kg/cm2||White||160 m||PE-100|