Sanitation which proves to be very cost effective

1. 3.1 Unit Introduction of Cost Effective Sanitation

9. Each gram of feces in an open field contain 10 million viruses,
1 million bacteria, and 1000 parasite cysts.

16. 3.2 Technology for On-site Sanitation

17. There are several technologies for disposal from household toilets. Most
technologies are a refinement of already known and practiced methods,
based on experience by different communities

18. 1. Twin Pit Pour Flush Water Seal Toilet

21.  The Twin Pit Water Seal Toilet is an on-site sanitation measure for
houses where the water table is sufficiently low to avoid ground water
pollution.

22.  On one hand it fulfills all sanitary requirements; of a toilet and on the
other provides continuous use with minimal maintenance.
 The main components of such a toilet are the two pits used alternately, a
pan, water seal / trap, squatting platform, junction chamber and a
superstructure.

23.  Under the system, there are two pits which are used alternately.
 Both pits are connected with a junction chamber at one end.
 Pit walls have a honeycomb structure.
 The bottom of the pit is not plastered and is earthen.
 Depending on the number of users of toilet, size of the pit varies.
Capacity of each pit is normally kept for three years.

24.  First pit, after it gets filled up in about three years, is blocked at the
junction chamber and second pit is put in operation.
 The watery part of excreta percolates in soil through the honey comb
structure.
 After two years of blockage of the first pit, its contents degrade
completely and turn to solid, odourless, pathogen free manure.

25.  It is dug out by beneficiaries and used for agriculture and horticulture
purposes.
 After the second pit is filled, it is similarly blocked and the first pit is put
in use again

26. Pan and trap / water seal:
The pan used in the pit toilet has a steep slope of 250-290. It may be made of
ceramic, mosaic or fiber. People normally do not accept mosaic pan as the
surface of such pan is not smooth and makes it difficult to clean it and
requires more water.

29. Size of the pit
The sizes of pits where ground water level is always below the bottom of
the pit and infiltration rate of soil is 30l / m2 /day for a three years sludge
storage volume works out as described in Table 5:

35.  Dry Toilet:
 A dry toilet is a toilet that operates without flush water.
 The dry toilet may be a raised pedestal on which the user can sit, or a
squat pan over which the user squats.

36.  In both cases, excreta (both urine and faeces) fall through a drop hole.
 The dry toilet is usually placed over a pit; if two pits are used, the
pedestal or slab should be designed in such a way that it can be lifted
and moved from one pit to another.

37.  Hole is covered with lid to prevent rodents entering into the chamber.
 After each use of toilet ash is put over faeces.
 The system is suitable for reuse of nutrients human excreta for agricultural
purposes.
 There is no chance of ground water pollution at all.

38.  However, in areas where people use water for ablution, the system is
difficult to be socially accepted.
 Further, due to lack of water seal, odour problem can’t be avoided.
 This also makes people hesitant in adopting the technology.

41.  A septic tank is a combined sedimentation and digestion tank where the
retention time of sewage is one to two days.
 During this period, settleable solids settle down to the bottom.

42.  This is accompanied by anaerobic digestion of settled solids (sludge)
and liquid, resulting in reasonable reduction in the volume of sludge,
reduction in biodegradable organic matter and release of gases like
carbon dioxide, methane and hydrogen sulphide.

43.  The effluent although clarified to a large extent, will still contain
appreciable amount of dissolved and suspended putrescible organic
solids and pathogens, as the efficiency is only 30-50 % for BOD and 60-
70 % for TSS removal.


44.  Several experiments and performance evaluation studies have established
that only about 30% of the settled solids are anaerobically digested in a
septic tank.
 When a septic tank is not desludged for a longer period, i.e., more than
the design period, substantial portion of solids escape with the effluent.

56. Anaerobic Baffled Reactor

57. Anaerobic Baffled Reactor
 An anaerobic baffled reactor (ABR) is an improved septic tank, which, after a
primary settling chamber, uses a series of baffles to force all kind of
wastewater to flow under and over the baffles as it passes from the inlet to the
outlet.

58.  The wastewater is introduced into the chamber at the bottom, leading to an
enhanced contact with the active biomass which results in an increased
retention and anaerobic degradation of suspended and dissolved organic
pollutants.

61. Anaerobic Filter

62. Anaerobic Filter
 The Anaerobic Filter is an improved design over Anaerobic Baffle Reactor
(ABR).
 In case of ABR, bacterial mass is flush out with effluent, resulting in less
degradation of organic matters.

63.  In case of Anaerobic Filter, suitable media are provided in chambers for the
growth and to retain microbes in chambers (Fig 4.32).
 This results in high population density of bacterial mass, resulting in higher
degradation of organic matters and thus lowering BOD of final effluent

66. 3.3 Sanitation Options in Rural Area

79. Salient features:
1. When the first pit gets filled up, the flow of excreta has to be diverted to the
second pit
2. Two leach pits are connected to one single pour-flush toilet
3. Twin-pit toilets have a high convenience
4. When emptying one pit, people use the another pit

80. 1. This technology has been widely used in the Government of
India’s Integrated Low Cost Sanitation Scheme (ILCS).
2. It is applicable where:

81. 1. (i) Water use is in the range 30–50 liters per capita per day depending
upon the characteristics of the soil or groundwater level.
2. (ii) The depth to the water table is 3 meters or more, allowing a clear 2-
meter vertical distance between the bottom of the pit and the water table.
Approximate cost = Rs. 7257

90. Salient features:
1. School Sanitation is a tool for promoting better sanitation and water
management for children.
2. Improves the school environment.
3. Privacy for school children.
4. Promoting proper hygiene behaviors from childhood.

91. 1. Operation and maintenance by school children
2. Separate facilities for children for urination and defecation
3. School toilets should be constructed within the school campus

92. 1. Incinerator should be installed in girls toilet for menstrual hygiene
management
2. One toilet is enough for primary school children.
3. Water facilities and hand washing facilities should be inside of the
toilet.

94. Salient features:
 School Sanitation is a tool for promoting better sanitation and water
management for children
 To improve the school environment
 Privacy for school children
 Following hygiene behaviors from the childhood

95.  Operation and maintenance by school children
 Separate facilities for children for urination and
defecation
 School toilets should construct within the school campus

96.  Incinerator should be installed in girl’s toilet for menstrual hygiene
management
 One toilet is enough for primary school children
 Water facilities and hand washing facilities should be inside of the toilet
 Approximate cost = Rs.56770

99. SULABH SAUCHALAYA – LOW COST SANITATION
Operation and Maintenance
Operation and maintenance of a Sulabh flush compost toilet is
very easy and simple:
•Before use, wet the pan by pouring only a little quantity of water.

100. •After defecation, pour 1.5 to 2 litres of water in the pan for flushing.
•Pour about half litre of water in the pan after urination.
•The pan should be cleaned once a day with a brush or a broom and with
soap powder periodically.

101. SULABH SAUCHALAYA – LOW COST SANITATION
•One of the pits is to be used at a time by plugging the drain for the other pit.
•Kitchen, bathroom waste water or rain water should not be allowed to enter
the pits.
•Other solid wastes like kitchen waste, rags, cotton, sweepings etc. should not
be thrown in the pan, this could block the toilet.

102. When the first pit in use is full, the flow should be diverted to the
second pit and the filled up pit should be desludged after 1.5 to 2-year
rest period. The first pit can then be put to reuse, when the second pit
fills up.

103. 3.3.1 Numerical on calculation for a two pit pour flush toilet

108. 3.3.2 Numerical on calculation of chambers for Ecosan toilet

112. 3.4 Cost Effective Sanitation Options in Urban Area

113.  Urban sanitation in India faces many challenges.
 Nearly 60 million people in urban areas lack access to improved sanitation
arrangements, and more than two-thirds of wastewater is let out untreated into
the environment, polluting land and water bodies.

114.  The overall goal of the National Urban Sanitation Policy (NSUP) is to
transform Urban India into community-driven, totally sanitized, healthy and
livable cities and towns.
 Each state needs to formulate its own sanitation strategy and their respective
cities should prepare sanitation plan in conformity with the NUSP.

115.  Swachh Bharat Mission-Urban (SBM-U) was launched on 2nd October, 2014,
by the Ministry of Housing and Urban Affairs as a national campaign to promote
cleanliness, sanitation, and proper waste management in urban areas.
 It aimed to make cities and towns across India clean and free from open
defecation.

116.  The purpose of urban sanitation is to reduce risks to human health by
managing factors in the urban environment which can contribute to health
problems.
 One of the major factors is human waste, which is generated in large volumes
in urban areas.

117.  So are facilities like public toilets, which discourage people from using the
streets as a bathroom, along with portable toilets for major events which are
designed to provide attendees with a location to safely eliminate waste.
 Urban sanitation also involves the management of water supplies.
 A good sanitation provide safe drinking water for citizens.

118.  Sanitation departments must also concern themselves with garbage.
 Most urban areas have a garbage collection service, allowing citizens to set out
their garbage on a specific day for teams of collectors who will gather it and
deliver it to a processing facility.
 Recycling and composting may be elements of municipal garbage collection,
designed to reduce strain on the environment and provide additional revenue
for the garbage collection agency, which keeps costs to consumers down.

120. System
template
providing a
schematic
overview of
the specific
inputs of a
sanitation
system

121. In this system,
all wastewater
that is created
by households,
institutions,
industries and
commercial
establishments
are collected,
transported
and treated
without stream
separation.

122. This system, like
the previous one, is
characterised by
flush toilets (full,
low, vacuum or
pour flush toilets)
at the user
interface.

123. In this
system, urine,
faeces and
flushing
water
(blackwater)
are collected,
transported
and treated
together.
However,
greywater is
kept separate

124. In this system,
faeces, flushing
water and
greywater are
collected,
transported and
treated together
but urine is kept
separate.

125. Here excreta - a
mix of urine and
faeces - are
discharged at the
user interface
without using
any flushing
water.

134. 3.5 Waste water Disposal of System

135. The study of the source of disposal is important because the amount of treatment
required to be given to a sewage depends very much upon the source of disposal,
its quality and capacity to tolerate the impurities present in the sewage effluents,
without itself getting potentially polluted or becoming less useful.

138. Disposal by Dilution

139. In this process the effluent from the sewage treatment plant is
discharged into
a river stream, or a large body of water such as a lake or sea.
•

140. The discharged sewage in due course of time, is purified by ‘self-purification
process of natural waters’.
• The degree of pollution depends upon the dilution, volume and composition of
the wastewater as compared to the volume and quality of the water with
which it is mixed.

141. Condition favoring Disposal by Dilution

150. Disposal of wastewater in confined in much more harmful than its disposal in
flowing streams and rivers.
• River is a flowing water body while lake has stagnant waters, so in lakes only
top surface would become saturated with DO, but the bottom layers would not
have enough oxygen.

151. • Overturning of layers would not occur frequently, so that DO content would not
be uniform through out the depth of lake.
• Overturning takes place only when there is change in the season due to which
there will be temperature difference between water in different layers which
cause change in the densities of different layers and overturning occurs.

153. The saturation concentration of dissolved oxygen in water decreases with
increasing salt concentration of DO in sea water is approximately 80 % of that in
water.
• In addition to this deficiency, the temperature of sea water is lower than the
sewage temperature, whereas the specific gravity is higher.

154. • Seawater contains a large amount of dissolved matter which chemically reacts
with the sewage solids, resulting in the precipitation of some of the sewage
solids, giving a milky appearance to the sea water and resulting in formation of
sludge banks and thin milky layer formed at the top of sea water produce
offensive hydrogen sulphide gas by reacting with sulphate rich sea water.

158. • In this method, the sewage effluent either treated or raw is disposed of
by applying it on land. The most common forms of land application are
irrigation (Sewage farming) and rapid infiltration.
•

159. • • When raw or partly treated sewage is applied on the land, a part of
it evaporates and remaining portion percolates in the soil. If proper
voids are maintained in the soil , the organic sewage solids are
oxidized by the bacteria present in the soil under aerobic condition.

160. • However, if the soil is made of heavy, sticky, and fine grained
materials, the void space will soon get clogged resulting in non
aeration of these voids which would lead to anaerobic condition
and subsequent evolution of foul gases.

161. • • Application of too strong or too hard of sewage will also result
in the quick formation of anaerobic conditions. The loads of
sewage can be reduced by dilution or pretreatment.

167. When the sewage is applied continuously on a piece of land, the soil
pores or voids may get filled up and clogged with sewage matter
retained in them. The time taken for such clogging will depend upon
the type of the soil and the load present in sewage.

168. • But once these voids gets clogged, free circulation of air will be prevented
an anaerobic conditions will develop within the pores. Decomposition of
organic matter would take place under anaerobic conditions with evolution
of foul gases like H2S, CO2 and methane. This phenomenon of soil getting
clogged, is known as sewage sickness.

169. 3.6 Ferro cement Drains & Conventional Drains

170.  In big cities, it is being made compulsory for large size residency to have rain
water harvesting system.
 For the present, drains are
being constructed with conventional materials such as brick/stone
masonry, and R.C.C. side drains are being constructed.
 Rain water is made to flow through these drains to centralized water storage
tank.

171.  From this tank, the water is expected to be used for the nondomestic and
gardening purposes.
 The water storage tank is of brick masonry or R.C.C.
 The drains for flow of rain water and the tank for storage of rain water is best
constructed using Ferro cement technology, which is far superior, durable
having least maintenance, least self weight and most tidy.

172.  The fibrocement drains are machine made precast products about 2.4 to 5
metres long with covers with perforations of the same length about 25 mm
thick.
 The surfaces of these drains are very strong and not eroded by flow of water.
 The bottom and sides of the water storage tanks consist of Ferro cement
plates with space frame.
 These plates are about 25 mm thick, waterproof, strong, durable and have
least maintenance.

181.  For urban areas i.e. cities and towns, roadside drains using Ferro cement
technology is of great advantage
 The work at site shall reduce considerably because precasting of road side
drains along with covers shall be carried out in precasting yard.
 As regards R.C.C. road side drains (a) the time taken for construction is quite
large

182.  The process of excavation, shuttering, reinforcement placing, concreting and
final laying of cover slabs is quite cumbersome, disturbing and inconvenient
to the BMC organisation as well as the public.
 The quality control is many times in doubt.
 The task of cleaning the drains is very much difficult, arduous and perhaps
the drain might get filled up to almost full after a lapse of some years.

183.  The reasons being the cleaning staff has to enter through manhole in a space
of about 10 ft. spacing and clean.
 In the case of Ferro cement drains, covers of length of 2.4 mtrs. to 3 mtrs.
can be made to handled manually or by a very light crane.
 These covers can be removed, set aside and whole drain is open for cleaning.
This cleaning can be conveniently done by means bucket excavation.
 The system shall be very much efficient, subject to easy supervision and
check and may be economical

184. 3.7 Summary of Unit

185. 1. Unit Introduction of Cost Effective Sanitation
2. Technology for Onsite Sanitation
3. Cost Effective Sanitation Options in Rural Area
1. Numerical on calculation for a two pit pour flush toilet
2. Numerical on calculation of chambers for Ecosan toilet
4. Cost Effective Sanitation Options in Urban Area
5. Waste Water Disposal System.
6. Concept of Ferro cement Drains and its Utilization in Rural Areas.
7. Summary of Unit