memanen air hujan.

siennatearfulUrban and Civil

Nov 25, 2013 (3 years and 8 months ago)

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MK. PSDA


PENGELOLAAN

DAN

PANEN AIR
HUJAN


diabstraksikan

oleh
:

soemarno
,
psdl.ppsub
,
juni

2013



AIR HUJAN

UNTUK

MENGATASI
KELANGKAAN AIR



KUALITAS AIR HUJAN

Diunduh

dari
:
https://docs.google.com/viewer?a=v&q=cache:GEXXuPgYvpEJ:www.who.int/water_sanitation_health/gdwqrevision/r
ainwater.pdf+&hl=en&pid=bl&srcid=ADGEEShSyNPyhojWp
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m0eII8ncj63YVUaob62uGVrThNXfz
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b6eQjB6YUI
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5AuzOijRNqyZ6n49GCOffBXZp9Ahutj9AFUVaP0Kr6b70P8TaUn8MJqor_o1onUX2Wzte0987I_89imvb&sig=AHI
EtbQVuuDWjOa
-
31OfDvnjAqyVWhE7Pg ………… 18/1/2013


Microbial contamination of collected rainwater indicated by E. coli (or,
alternatively,
thermotolerants

coliforms
) is quite common, particularly in
samples collected shortly after rainfall. Pathogens such as
Cryptosporidium,
Giardia
, Campylobacter,
Vibrio
, Salmonella,
Shigella

and Pseudomonas have also been detected in rainwater.


However, the occurrence of pathogens is generally lower in rainwater
than in unprotected surface waters, and the presence of non
-
bacterial
pathogens, in particular, can be minimized.


Higher microbial concentrations are generally found in the first flush of
rainwater, and the level of contamination reduces as the rain continues.



A significant reduction of microbial
contamination can be found in rainy seasons
when catchments are frequently washed with
fresh rainwater.


Storage tanks can present breeding sites for
mosquitoes, including species that transmit
dengue virus.


KUALITAS AIR HUJAN

Diunduh

dari
:
https://docs.google.com/viewer?a=v&q=cache:GEXXuPgYvpEJ:www.who.int/water_sanitation_health/gdwqrevision/rainw
ater.pdf+&hl=en&pid=bl&srcid=ADGEEShSyNPyhojWp
-
m0eII8ncj63YVUaob62uGVrThNXfz
-
b6eQjB6YUI
-
5AuzOijRNqyZ6n49GCOffBXZp9Ahutj9AFUVaP0Kr6b70P8TaUn8MJqor_o1onUX2Wzte0987I_89imvb&sig=AHIEtbQ
VuuDWjOa
-
31OfDvnjAqyVWhE7Pg ………… 18/1/2013

Rainwater is slightly acidic and very low in dissolved minerals; as such, it is
relatively aggressive. Rainwater can dissolve heavy metals and other impurities
from materials of the catchment and storage tank.

In most cases, chemical concentrations in rainwater are within acceptable limits;
however, elevated levels of zinc and lead have sometimes been reported.

This could be from leaching from metallic roofs and storage tanks or from
atmospheric pollution.


Faktor
-
faktor

yang
menentukan

kualitas

air
hujan

yang
dipanen


Water quality is determined by the composition of water as
affected by natural processes and human activities. Water quality
depends on the constituents dissolved or contained within the
water. It is often presumed that the chemical composition of water
is the only factor involved.

However, especially (micro) biological factors are of main
importance when considering water quality.


Diunduh

dari
:
http://webcache.googleusercontent.com/search?q=cache:yUYlQg6UFloJ:www.rainfoundation.org/fileadmin/
PublicSite/Manuals/RAIN_Rainwater_Quality_Policy_and_Guidelines_2009_v1.pdf+&hl=en ………..
19/1/2013

KONTAMINASI AIR HUJAN


Atmospheric pollution can have a major effect on the composition of rainwater.
Water that reaches the earth as rain, acquires other substances from processes
such as leaching, weathering, and dissolution. Living organisms may enter the
water. All these processes affect the composition of the water. Depending on the
source of the contamination, three types can be distinguished:


1. (Micro)biological contamination:

The most common hazard in water sources obtained from roof or surface
catchments is microbial (biological and microbiological) contamination,
especially enteric pathogens. Enteric pathogens are micro
-
organisms (bacteria,
viruses, and protozoa) that cause gastrointestinal illness. These organisms are
introduced into drinking water supplies by contamination with
faecal

material
(from human or animal origin) or dead animals and insects (
enHealth
, 2004). The
most important indicator is E
-
Coli.


2. Chemical contamination:

Chemical contamination results from air pollution (industrial and traffic
emissions), runoff and leaching of chemical substances (agricultural and human
activities) and toxic material use. All these factors can pose a serious a health
threat. However, in rural areas of developing countries, these activities are mostly
absent or very small
-

scale (for example: fireplaces near a roof or having a
chimney can cause soot to settle on the roof), and are therefore unlikely to cause
significant impacts on the quality of the collected rainwater (
enHealth
, 2004).


3. Physical contamination:

Physical contamination includes inorganic and organic sediments like sand, silt,
clay, or plant material. Physical contamination affects the
colour
,
odour

or taste
of the water, but it poses no direct health risk. Users can however object to water
if its
colour
,
odour

and taste are found less attractive

Diunduh

dari
:
http://webcache.googleusercontent.com/search?q=cache:yUYlQg6UFloJ:www.rainfoundation.org/fileadmin/
PublicSite/Manuals/RAIN_Rainwater_Quality_Policy_and_Guidelines_2009_v1.pdf+&hl=en ………..
19/1/2013

KUALITAS AIR HUJAN

RAINs water quality criteria


Based on the WHO Guidelines for Drinking Water Quality (2004), water quality
analyses from RAINs water quality surveys in Burkina Faso, Ethiopia en Nepal
in 2007, RAIN has set water quality criteria for potable water as listed in the
table below.

RAINs criteria for water quality based on WHO guidelines.

Roofwater

harvesting

Surface
Runoff

Sand dams


E
-
Coli

< 10
cfu
/100 ml


<10
cfu
/100 ml

<10
cfu
/100 ml


Ammonia

< 1.5 mg/l


< 1.5 mg/l


< 1.5 mg/l


Khlorine

> 0.2


0.5 and <
5 mg/l

> 0.2


0.5 and
< 5 mg/l


> 0.2


0.5 and < 5
mg/l


Aluminium

Not relevant

< 0.2 mg /l


< 0.2 mg /l


pH

6.5.
-

8.5

6.5


8.5


6.5


8.5


Turbiditas

Not relevant

< 15 NTU

< 5 NTU


Nitrate /
Nitrite

Not relevant


< 50 mg/l and
< 3 mg/l


< 50 mg/l and < 3
mg/l


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:
http://webcache.googleusercontent.com/search?q=cache:yUYlQg6UFloJ:www.rainfoundation.org/fileadmin/PublicSite
/Manuals/RAIN_Rainwater_Quality_Policy_and_Guidelines_2009_v1.pdf+&hl=en ……….. 19/1/2013

KUALITAS AIR HUJAN

Baseline and long
-
term water quality survey

After the first rainy season after completion of a RWH system, a water quality
survey should be done. This survey will also give a general idea of the
performance of each system, the skills of construction of the implementing
partner and the community operation and management. The results of this first
survey will lead to fine
-
tuning of RWH system; identifying construction flaws,
identifying operational, maintenance and management flaws and selecting most
optimal treatment measures.


RAINs methodology for water quality surveys

Diunduh

dari
: ……….. 19/1/2013

Baseline
survey

Long
-
term survey


Period


After 1st rainy
season after
construction

After rainy season


Nr. of RWH

systems


All RWH
systems

constructed
that year

Random selection of 30% of all
tanks (> 1 year old)


Parameters


All parameters

Roofwater

harvesting:

• E
-
C潬椬

• Chlorine, if
ch汯物湡瑩潮

has been
applied.

Surface runoff and sand
dams:

• E
-
C潬椬

• Turbidity,

• Chlorine, if
h汯物湡瑩潮

has been applied,


Aluminium
, if it has
been applied.

Period

November


December

KUALITAS AIR HUJAN

Risks to human health and aesthetic acceptance of RAIN water quality criteria

Diunduh

dari
: ……….. 19/1/2013

E
-
Coli or
faecal

coliforms

Examples of diseases which are waterborne (caused by contaminated drinking water)
include cholera, typhoid, hepatitis,
amoebiasis
, and
dracunculiasis
. The causes of the
high levels of contamination/pollution of surface water are often due to hanging latrines
and direct sewage discharge (without any minimum treatment etc.) into surface waters
and close proximity of latrines or drains (
WaterAid
, 2008).


Ammonia

Ammonia is an indicator of water pollution caused due to human activities and natural
decay processed. Harvested rainwater may contain ammonia as a result of the decay
process in the storage tank. Groundwater often contains some ammonia due to natural
reduction of nitrate by bacteria, but sudden change in ammonia may be due to
contamination of wastewater through seepage (
WaterAid
, 2008).


Chlorine

Free (or residual) chlorine in drinking water is only relevant where supplies are
chlorinated, or where routine or emergency chlorination has taken place. The presence
of free (residual) chlorine is an indication that removal of bacterial contamination is
continuing within the supply. Exposure to extremely high levels of pure chlorine gas
can cause lung collapse and death (
WaterAid
, 2008).


Aluminium

In humans,
aluminium

and its compounds appear to be poorly absorbed, although the
rate and extent of absorption have not been adequately studied for all sectors of the
population. There is little indication that orally ingested
aluminium

is acutely toxic to
humans despite the widespread occurrence of the element in foods, drinking
-
water and
many antacid preparations. It has been hypothesized that
aluminium

exposure is a risk
factor for the development or acceleration of onset of Alzheimer disease (AD) in
humans (Guidelines for Drinking Water Quality, WHO, 2004).


KUALITAS AIR HUJAN

Risks to human health and aesthetic acceptance of RAIN water quality criteria

Diunduh

dari
: ……….. 19/1/2013

pH

According to the WHO guidelines, no health
-
based guideline value is proposed for pH,
although eye irritation and exacerbation of skin disorders have been associated with pH
values greater than 11. Although pH usually has no direct impact on consumers, it is
one of the most important indicative water quality parameter for operational
management, since pH determines the effectiveness of the treatment (
WaterAid
, 2008).


Turbidity

Turbidity which is a measure of extent to which light is either absorbed or scattered by
suspended materials in water is an indicator of suspended solids present in water. These
suspended solids can be in the form of silt, clay, sand, industrial wastes, sewage,
organic matter, phytoplankton and other microbial organisms. Turbidity is an important
parameter to be considered in drinking water supplies due to aesthetics, filterability and
disinfection. Turbidity is also measured to determine what type and level of treatment
are needed (
WaterAid
, 2008).


Nitrate and Nitrite

Nitrate is the most widespread agriculture contaminant but presence of nitrate/nitrite is
considered to have minimal effect on the disease burden. The WHO guideline value for
nitrate in drinking water of 50mg/
litre

(equivalent to 10mg/
litre

nitrate
-
nitrogen) and
3mg/l for nitrite (short
-
term exposure) is established solely to prevent Cyanosis
(
methaemoglobinaemia
) in babies: bottle
-
fed infants of less than 3 months of age are
most susceptible although occasional cases have been reported in some adult
populations. The long term exposure to Nitrate/Nitrite is, however, a human health
concern as it may increase stomach cancer. A recent study suggested that miscarriage
might also be linked to high nitrate levels, although scientists have not confirmed this
(
WaterAid
, 2008).

KUALITAS AIR HUJAN

System assessment: mapping the risks of contamination

Generally treating and filtering of water seems the obvious method for obtaining a certain
water quality. This, however, is an end
-
of
-
pipe solution. If contamination resulted from for
example use of toxic materials or by poor maintenance, re
-
contamination will certainly occur.

By following a top
-
down method of preventing contamination, a more cost
-
effective
approach can be reached.




Pemetaan

risiko

kontaminasi

pada

sistem

Pemanenan

air
hujan


(based on www.eng.warwick.ac.uk/DTU/rwh/components1.html)

Diunduh

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:
http://webcache.googleusercontent.com/search?q=cache:yUYlQg6UFloJ:www.rainfoundation.org/fileadmin/PublicSite
/Manuals/RAIN_Rainwater_Quality_Policy_and_Guidelines_2009_v1.pdf+&hl=en ……….. 19/1/2013

Area

Industrial, agricultural or
human activities

influencing water quality by
air, water or soil









Preven
-
tion

Catchment

surface


Roof, paved or unpaved
surface, dry

riverbed, maintenance

Conveyance


Gutters, inlet
constructions or riverbeds,
maintenance

Filtra
-
tion

Storage


RWH systems,
maintenance


Treat
-
ment

Delivery


Taps, hand pumps, operation
and management

Filtra
-
tion

KUALITAS AIR HUJAN

Faktor

Keadaan

Area


The area can be described as the external factors influencing the background or
reference water quality in a RWH system and can be divided into physical and
social factors:


1.
Physical factors:


The air, water and soil pollution present within the area, resulting from
industrial and agricultural activities and geology directly influences the water
quality of the RWH system. Mostly these factors are difficult to influence,
but should be taken into account when starting a RWH project. In rural areas
their influence is relatively small and can often be excluded, but can reflect
unexpected outcomes in water quality tests.


2.

Social factors:


Human conduct and level of education, reflected in the level of awareness of
the relation between water and health, hygiene and sanitation, management
and maintenance skills of RWH systems are social factors controlling water
quality of a RWH system.

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/Manuals/RAIN_Rainwater_Quality_Policy_and_Guidelines_2009_v1.pdf+&hl=en ……….. 19/1/2013

KUALITAS AIR HUJAN


Permukaan

Daerah
Tangkanan

air
hujan


The catchment surface can be described as the area on which the rainfall is
collected. Depending on the type of RWH system, several catchment surfaces
can be defined, i.e. roofs, paved or unpaved surfaces, dry sandy river beds.


Contamination can be prevented by:

1.
Using non
-
toxic materials for roofing, like cement, corrugated and
galvanised

iron. Metal roofs subjected to atmospheric corrosion can act as a
source of heavy metals;

2.
Frequently cleaning and clearing of the catchment surface (from human,
animal and organic matter), removing overhanging branches and fencing off
of the catchment area in the case of surface runoff.


Faecal

contamination of water from rooftops can result from animal droppings on
the roof surface. Water harvested from ground surfaces is vulnerable to
contamination by animal or human
faeces
. The larger the catchment surface, the
bigger the chance for contamination due to more complex management of the
catchment.


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http://webcache.googleusercontent.com/search?q=cache:yUYlQg6UFloJ:www.rainfoundation.org/fileadmin/PublicSite
/Manuals/RAIN_Rainwater_Quality_Policy_and_Guidelines_2009_v1.pdf+&hl=en ……….. 19/1/2013

KUALITAS AIR HUJAN


Penyaluran

Air
Hujan


The conveyance can be described as the means of transportation of the collected
rainfall from the catchment surface to the storage system. Depending on the type
of RWH systems, several conveyances can be defined: gutters, inlet pipes, and
collection and inlet canals.


Contamination can be prevented by:

1.
Using non
-
toxic materials;

2.
Frequently cleaning of the conveyances. Debris and pools should not remain
in the gutters, since they can become pools of contamination.


Contamination might have occurred in the previous level (the catchment area).
Therefore filters should be installed at the entrance or end of the gutters or inlet
canals to prevent (small) animals, organic matter and debris from entering the
RWH system.


A first
-
flush device should be installed to divert the first (
millimetres

of) rainfall,
which contains the main load of pollution.


Diunduh

dari
:
http://webcache.googleusercontent.com/search?q=cache:yUYlQg6UFloJ:www.rainfoundation.org/fileadmin/PublicSite
/Manuals/RAIN_Rainwater_Quality_Policy_and_Guidelines_2009_v1.pdf+&hl=en ……….. 19/1/2013

PEMANENAN AIR HUJAN

Penyimpanan

Air
Hujan


The storage can be described as the structure or medium in which the rainwater is stored. In

RAINs current
programme

three different types of RWH systems can be defined: above
ground tanks, below ground tanks and sand dams. Contamination can be prevented by:

1.
Using non
-
toxic construction materials;

2.
Using adequate covering to prevent influence from direct sunlight, human, animal and
organic matter from entering the storage system and mosquito breeding.


Contamination might have occurred in the previous levels. Treatment of the water can be
applied when found necessary (see table 1 and annexes 3 a, b and c). Residence in the storage
system itself provides opportunities for water purifying processes such as sedimentation,
bacterial die
-
off and filtration (for sand dams), increasing the water quality over time.
Cleaning of the storage system should only be done if the previous water was found to be
contaminated (see annex 6). Surface runoff storage systems will contain a lot of soil material
which has to be removed every year when the tank is empty (before the rainy season) since it
not only affects the water quality, but also decreases the tank capacity. Sand dams have no
closed storage system which makes it even more important to limit contamination risks as
much as possible in the previous levels.



Other possible risks of contamination at the storage level are:

1.
Frequent opening of the manhole. Although many people see opening of the manhole as
necessary to investigate the water quality (by
colour
,
odour
, debris etc); it will pose a
bigger risk to contamination since debris might fall into the tank. Children sometimes
use the tank to bath in, which is not only dangerous, but will increase risks of
contamination.

2.
Mixing of tank water or filling of a tank with water from other sources. If water from
another source has been tested and found not contaminated, the water can be mixed
under well
-
controlled circumstances with the water in the RWH system. If the water is
not tested, chlorination should always be applied after mixing with the water in the
RWH system.




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/Manuals/RAIN_Rainwater_Quality_Policy_and_Guidelines_2009_v1.pdf+&hl=en ……….. 19/1/2013

PEMANENAN AIR HUJAN


Distribusi

Air
Hujan

(Delivery)


The delivery can be described as delivery point to the user, hence the pump or tap
by which the user fetches the water.



Kontaminasi

air
hujan

dapat

dicegah

dnegan

jalan
:


1.
Proper management of the water distribution;

2.
Creating awareness on hygiene issues (hygiene education). People can
contaminate the water by non
-
hygienic use of the taps or pumps, as well as
use of unclean containers after extraction.

3.
Closing the area around the delivery point for animals, because they can
infect the water by drinking from the (leaking) taps or pumps;

4.
Preventing water pools around the RWH systems which could enhance
mosquito breeding for example by increasing the infiltration capacity of the
soil at the delivery point (gravel). The picture on the right shows a good
example of increasing the infiltration capacity near the tap of an above
ground tank.


Diunduh

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:
http://webcache.googleusercontent.com/search?q=cache:yUYlQg6UFloJ:www.rainfoundation.org/fileadmin/PublicSite
/Manuals/RAIN_Rainwater_Quality_Policy_and_Guidelines_2009_v1.pdf+&hl=en ……….. 19/1/2013

PANEN AIR HUJAN:
Improving

water
quality

Recommended treatment and filtering methods


Water treatment only makes sense if it is done properly, and if hygienic
collection, storage and use of water ensure prevention of recontamination. Due to
the fact that RAIN works in remote areas, a selection has been made of practical
and acknowledged treatment and filter techniques, presented in table 1. Until now
RAIN only has had experience with chlorination.


RAINs recommended treatment and filtering methods for RWH systems

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Treatment method

Roof
runoff


Surface
runoff

Sand

dam

Solutions or
substances

to be added to
water:

Chlorination

Tank

Household


Household


Silver coated ceramic
balls

Tank

Household


Household


Aluminium

sulphate


Household
/Tank


Household



Moringa

oleifera

and

stenopetala

Household/
Tank


Household



Filters:


Ceramic pot filter

Household

Household


Household


Bio
-
sand filter

Household


Household


Household


Heat and UV
radiation:


Boiling

Household


Household


Household


SODIS

Household


Household


Household


PANEN AIR HUJAN:
Improving

water
quality

KERANGKA
-
KERJA
Perbaikan

Higienis

Air
Hujan


Hygiene promotion works best when combined with improvements in water supply and sanitation services.
The Environmental Health Project EHP therefore developed the Hygiene Improvement Framework (HIF),
which combines the multiple fronts to fight water
-
related diseases and uses lessons learned from y ears of
program experience. Three key elements can be defined: access to the necessary technologies, promotion of
healthy
behaviours
, and support to ensure long
-
term sustainability. The HIF can be used as a framework to
find the missing elements within a water supply and sanitation project.

Sanitation and hygiene play an important role in water supply projects. However RAIN will focus on
providing sufficient and safe drinking water and will seek collaborations with national or international
organisations

with experience on sanitation and hygiene.


The Hygiene Improvement Framework (The Hygiene Improvement Framework, 2004).

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Access to Water and

Sanitation

Access to Water and

Sanitation

Enabling Environments

1.
Water supply systems

2.
Sanitation Facilities

3.
Household
-
level
technologies and
materials

1.
Behavioral / Social
change methods

2.
Community
mobilization

3.
Social Marketing

4.
School programs

5.
Community
participation in
problem identification
and Solutions

1.
Policy improvement

2.
Institutional
strengthening

3.
Community
involvement

4.
Financing and cost
recovery

5.
Cross
-
sector and
public
-
private
partnerships




Hygiene Improvement


KUALITAS AIR HUJAN

Diunduh

dari
:
https://docs.google.com/viewer?a=v&q=cache:GEXXuPgYvpEJ:www.who.int/water_sanitation_health/gdwqrevision/r
ainwater.pdf+&hl=en&pid=bl&srcid=ADGEEShSyNPyhojWp
-
m0eII8ncj63YVUaob62uGVrThNXfz
-
b6eQjB6YUI
-
5AuzOijRNqyZ6n49GCOffBXZp9Ahutj9AFUVaP0Kr6b70P8TaUn8MJqor_o1onUX2Wzte0987I_89imvb&sig=AHI
EtbQVuuDWjOa
-
31OfDvnjAqyVWhE7Pg ………… 18/1/2013


Rainwater lacks minerals, but some minerals, such as calcium,
magnesium, iron and fluoride, in appropriate concentrations are
considered very essential for health. Although most essential
nutrients are derived from food, the lack of minerals, including
calcium and magnesium, in rainwater may represent a concern
for those on a mineral
-
deficient diet.


In this circumstance, the implications of using rainwater as the
primary source of drinking
-
water should be considered. The
absence of minerals also means that rainwater has a particular
taste or lack of taste that may not acceptable to people used to
drinking other mineral
-
rich natural waters.


Water quality should be managed through development and
application of WSPs that should deal with all components from
catchment areas to point of supply.


KUALITAS AIR HUJAN

Diunduh

dari
:
https://docs.google.com/viewer?a=v&q=cache:GEXXuPgYvpEJ:www.who.int/water_sanitation_health/gdwqrevision/r
ainwater.pdf+&hl=en&pid=bl&srcid=ADGEEShSyNPyhojWp
-
m0eII8ncj63YVUaob62uGVrThNXfz
-
b6eQjB6YUI
-
5AuzOijRNqyZ6n49GCOffBXZp9Ahutj9AFUVaP0Kr6b70P8TaUn8MJqor_o1onUX2Wzte0987I_89imvb&sig=AHI
EtbQVuuDWjOa
-
31OfDvnjAqyVWhE7Pg ………… 18/1/2013


The first flush of rainwater carries most contaminants into
storages. A system is, therefore, necessary to divert the
contaminated first flow of rainwater from roof surfaces.

Some devices and good practices are available to divert the first
foul flush of rainwater. Automatic devices that prevent the first
20

25
litres

of runoff from being collected in storages are
recommended. If diverters are not available, a detachable down
-
pipe can be used manually to provide the same result. Even with
these measures in place, storages will require periodic cleaning to
remove sediment.


Storages without covers or with unprotected openings will
encourage mosquito breeding, and sunlight reaching the water
will promote algal growth. Covers should be fitted, and openings
need to be protected by mosquito
-
proof mesh. Cracks in the tank
and withdrawing of water using contaminated pots can
contaminate stored water.


Storages should preferably be fitted with a mechanism such as a
tap or outlet pipe that enables hygienic abstraction of water. Some
households incorporate cartridge filters or other treatments at the
point of consumption to ensure better quality of drinking
-
water
and reduce health risk.


AIR HUJAN DAN KEKURANGAN AIR


Population increase


Industrialization


Urbanization



(a) Increase in per capita utilization



(b) Less peculation area


In places where rain fed/ irrigation based crops are cultivated through
ground water


Decrease in surface area of Lakes,
talab
, tanks etc.


Sumber
: http://rainwaterharvestingireland.net/why
-
rainwater
-
harvesting
-
in
-
ireland
-
pays
-
for
-
itself/

What is a rainwater harvesting system?

A
rainwater harvesting system

basically collects rainwater and
stores it for later use. All throughout history, this has been done but
with the creation of mains water supply, this practice has all but died
out in the western world.

Ireland is a country that is lucky enough to have a large amount of
rainfall over any one year period. rainwater harvesting systems store
rainwater and use it to supplement the uses of the non potable water.


How Can I harvest Rainwater?

There are quite a few different ways you can harvest rainwater.

The most popular way is the use of water barrels which can hold over
200
litres

of water. Many of these barrels have a tap built into the
base of the water butt.

The next step would be to add a water pump. There are plenty on the
market and the same water can be used for watering gardens,
cleaning cars and patio areas etc. The beauty of water barrels is that
they require very little maintenance apart from the occasional
cleaning which means just taking out debris such as leaves from the
built in filters.


Deforestation

(
i
) Less precipitation

(ii) Absence of Barriers



(a) Rain drops checked by leaves of tree



(b) Water slowly descends through twigs &
trunk



© Humus


acts as reservoir



(d) Tiny creatures


helps percolation


1 hectare of forest
-
6
-
7 Lac ton of water

(after filtering) top layer can hold 1.2 Lac tons of water

Sumber
: Rain water harvesting,
Gautam

Banerjee
, UP
Jal

Nigam

MENGAPA KEKURANGAN AIR ?

What is the solution ?


Rain water is the ultimate source of fresh water


Potential of rain to meet water demand is tremendous


Rain water harvesting helps to overcome water scarcity


To conserve ground water the aquifers must be recharged with
rain water


Rain water harvesting is the ultimate answer

Sumber
: Rain water harvesting,
Gautam

Banerjee
, UP
Jal

Nigam

Why Rain water be harvested


To conserve & augment the storage of ground water


To reduce water table depletion


To improve the quality of ground water



To arrest sea water intrusion in coastal areas


To avoid flood & water stagnation in urban areas


What is rain water harvesting ?


1.
It
is the activity of direct collection of
rain water

2.
Rain water can be stored for direct
use or can be recharged into the
ground water aquifer

Sumber
: Rain water harvesting,
Gautam

Banerjee
, UP
Jal

Nigam

The roof catchment are selectively cleaner when
compared to the ground level catchment

1.
Losses from roof catchment are minimum

2.
Built & Maintained by local communities

3.
No Chemical contamination & only required
filtration

4.
Available at door step with least cost

The typical roof top rain water harvesting system
comprises


Roof catchment


Gutters


Down pipe & first flushing pipe


Filter Unit


Storage Tank

Sumber
: Rain water harvesting,
Gautam

Banerjee
, UP
Jal

Nigam

Roof catchment

The roof of the house is used as the catchment for collecting
rain water. The style construction and material of the roof effect
its suitability as a catchment, Roofs made of corrugated iron
sheet , asbestos sheet, Tiles or Concrete can be utilized for
harvesting the rain water


Gutters
-

Talang

Air
Hujan


Gutters are channels fixed to the edges of roof all around to collect
& transport the rainwater from the roof. Gutters can be made in
semi
-
circular and rectangular shape with cement pipe, plain
galvanized iron sheet, PVC pipes, bamboos etc. Use of locally
available material reduce the overall cost of the system.

Sumber
: Rain water harvesting,
Gautam

Banerjee
, UP
Jal

Nigam

Each
rainwater harvesting

system consists of at least the following
components (INFONET
-
BIOVISION 2010):

1.
Rainfall

2.
A catchment area or roof surface to collect rainwater.

3.
Delivery systems (gutters) to transport the water from the roof or
collection surface to the storage
reservoir
.

4.
Storage reservoirs or tanks to store the water until it is used.

5.
An extraction device (depending on the location of the tank
-

may be
a tap, rope and bucket, or a pump (HATUM & WORM 2006); or a
infiltration device in the case the collected water is used for well or
groundwater recharge.

Diunduh

dari
:
Sumber
: http://www.sswm.info/category/implementation
-
tools/water
-
sources/hardware/precipitation
-
harvesting/rainwater
-
harvesting
-
r …………. 19/1/2013

Down Pipe


It is the pipe which carries the rainwater from the gutters to
the filter & storage tank. Down pipe is joined with the gutters
at one end & the other end is connected to the filter unit of
the storage tank. PVC or GI pipe of 50mm to 75mm (2 to”)
are commonly used for down pipe. Bamboo can be also used
wherever available and possible

Sumber
: Rain water harvesting,
Gautam

Banerjee
, UP
Jal

Nigam

Rain Water Harvest Plant:

The water reaching the Roof through precipitation is allowed to flow down
by an exhaust pipe which can be connected to a filter which further empties
itself into the tube wells.

As a result of this small method we can recharge the groundwater and
prevent the underground water table from further deterioration.

Diunduh

dari
: http://www.udaipurblog.com/save
-
water.html…………. 19/1/2013

First Flush Pipe

Debris
, dust & dirt collect on the roof during non rainy periods
when the first rain arrive.

A
first flush system arrangement is made to avoid the entering
unwanted material into the Filter media & storage tank. This is a
simple manually operated arrangement or semi
-
automatic
system with a valve below the ‘T’ junction

Sumber
: Rain water harvesting,
Gautam

Banerjee
, UP
Jal

Nigam

Roof materials and pipes

Some roofing materials are not suitable for rainwater collection
-
check with the manufacturer.


A typical rainwater system is set up
to
minimise

contamination.

Diu8nduh
dari

Sumber
: http://www.whakatane.govt.nz/Services/Water/Water
-
Usage/Collecting
-
and
-
using
-
rainwater/… 19/1/2013

Filter Unit


The filter unit is a container or chamber filled with filter
media such as coarse sand, charcoal, coconut fiber, pebbles & gravels to
remove the debris & dirt from water that enters the tank. The filter unit
is placed over the storage tank or separately. It may be of Ferro cement
filter unit, Aluminum, Cement rings or Plastic bucket etc.

Sumber
: Rain water harvesting,
Gautam

Banerjee
, UP
Jal

Nigam

Diu8nduh
dari

Sumber
: http://www.sswm.info/category/implementation
-
tools/water
-
sources/hardware/precipitation
-
harvesting/rainwater
-
harvesting
-
r … 19/1/2013

llustration

of water flow scheme of a RTRWH system. Basic
components: roof, gutters,
first flush device

(first rain separator),
rain barrel with filter and tap and recharge well.

Source: RAINWATERCLUB (Editor) (
n
.y
.)

Storage Tank


It
is used to store the water that is collected from the roof through filter. For
small scale water storage plastic buckets, jerry cans, clay or cement jars, ceramic
jars, drums may be used. For larger quantities of water, the system will require a
bigger tank with cylindrical or rectangular or square in shape constructed with
Ferro cement or cement rings or plain cement concrete or reinforced cement
concrete or brick or stone etc. The storage tank is provided with a cover on the
top to avoid the contamination of water from external sources
.
The storage tank
is provided with pipe fixtures at appropriate places to draw the water to clean
the tank & to dispose of extra water. A provision for keeping the vessel to collect
the water is to be made.

Sumber
: Rain water harvesting,
Gautam

Banerjee
, UP
Jal

Nigam

Diu8nduh
dari

Sumber
: http://www.nzdl.org/gsdlmod?e=d
-
00000
-
00
---
off
-
0fnl2.2
--
00
-
0
----
0
-
10
-
0
---
0
---
0direct
-
10
---
4
-------
0
-
1l
--
11
-
en
-
50
---
20
-
about
---
00
-
0
-
1
-
00
-
0
--
4
----
0
-
0
-
11
-
10
-
0utfZz
-
8
-
00&cl=CL3.31&d=HASH3d2b712eafacff9c7fe5f7.4.1.1.1&gt=1 ………….. 19/1/2013

Schematic of a rainwater catchment and storage system.

UKURAN TANKI PENYIMPAN AIR HUJAN

Ukuran

tanki

berdasarkan
:


No. of person in the House hold


Per capita water requirement


No. of days for which water is
required.

Example

Drinking water requirement for a household with 5 family
members, period 8 months & 6
lpcd


= 5x 180x
6 =
7200 Liters

Sumber
: Rain water harvesting,
Gautam

Banerjee
, UP
Jal

Nigam

The rainwater can be collected in pots at the edge of the roof or ideally from down
-
pipes
connected to gutters. When it first starts to rain, debris from the top of the roof or gutters
is washed into the down
-
pipe, so it takes a while for clean water to filter through the
system. A technique to remove this first flush of dirty water is by the use of down
-
pipe
flaps. When it starts to rain, the flap is closed and the water is directed away from the
storage tank onto the
ground
. Once clean water can be collected, the down pipe flap can
be opened and the clean water is diverted into a storage tank. Fitting sieves to the top of
the down pipe further decreases the risk of dirt getting into the water.

Sumber
: http://www.theinnovationdiaries.com/811/rainwater
-
harvesting
-
techniques/…… 19/1/2013

Air
hujan

yang
tersedia

dari


cucuran

atap

bangunan

Annual rainfall (in mm) x roof area (in sq. m) x
co
-
efficient of run off for roof



co
-
efficient of run off



GI sheet


0.9



Asbestos


0.8



Tiled



0.75

Plaster
on bricks/ Concrete

0.7


Water
available from roof top
800 mm x
20
sq.m

= 12800
Liters per annum

Sumber
: Rain water harvesting,
Gautam

Banerjee
, UP
Jal

Nigam


Size of Tank


=1.2 m
dia

1.8 m height


No. of Tanks


4


Volume of
Tanks 3.14x1.2x1.2x1.5/4 2.03 cum 2000
liters


Volume of
of

4
tanks =

4x2000 8000
Liters


(this can be designed as per requirement)

Schematic of a rainwater catchment system.

Diu8nduh
dari

Sumber
: http://www.nzdl.org/gsdlmod?e=d
-
00000
-
00
---
off
-
0fnl2.2
--
00
-
0
----
0
-
10
-
0
---
0
---
0direct
-
10
---
4
-------
0
-
1l
--
11
-
en
-
50
---
20
-
about
---
00
-
0
-
1
-
00
-
0
--
4
----
0
-
0
-
11
-
10
-
0utfZz
-
8
-
00&cl=CL3.31&d=HASH3d2b712eafacff9c7fe5f7.4.1.1.1&gt=1 ………….. 19/1/2013

Air
hujan

yang
tersedia

dari


cucuran

atap

bangunan


Sistem

Pemanen

Air
Hujan

mempunyai

tiga

fase
:




1)
Mengumpulkan

dan

mengangkut

air
hujan


This is done through catchment areas & conduits. The catchment of a
water harvesting system is the surface which receives rainfall directly.
It can be a paved area like the terrace or courtyard of a building.


Conduits are the pipelines that carry rainwater from the catchment or
rooftop to the harvesting system.



2)
Filtrasi

=
Menyaring

untuk

membersihkan


In case of rooftop rainwater harvesting specially designed filters are
used to filter the rainwater before it is stored in a storage tank for non
-
potable usage. PURE RAIN has the
Purain

range of RWH filters for the
same


For groundwater recharging, the rooftop or ground water needs to be
properly filtered so that the water does not contaminate the
underground aquifers. PURE RAIN has a specially design groundwater
recharging system
-

Jal

Rakshak

that not only filters the water but also
holds it while it percolates into the ground.



3)
Menyimpan

dalam

tanki

untuk

dimanfaatkan

/
untuk

mengisi

groundwater


The harvested water can now be stored in storage tanks for immediate
non
-
potable usage, which are designed according to your water
requirements.


Existing non
-
potable water storage tanks in the society can also be used
to store the harvested rainwater.


For groundwater recharging you need to design a collection chamber
that holds the water while it percolates into the ground as the rate of
percolation is much lower than the intensity at which it rains.


Diu8nduh
dari

Sumber
: http://gibo13
-
purerain
-
primary.cluster2.hostgator.co.in/rainwater
-
harvesting …………..
19/1/2013

MEMANEN AIR HUJAN.

Sumber
: ….. http://www.riomay.com/renewable
-
technologies/rain
-
water
-
harvesting

Riomay
®

Renewable Energies has a range of rainwater harvesting
products that provide versatile, economic and ecological solutions and
give consumers the ability to freely collect water and use it without
feeling guilty; on their plants and lawns, for washing their cars, in their
washing machines and in their toilets.

Bagaimana

meminimumkan

problematik
?

1
By providing pipe water system with source
(electric based)

(a) Surface water

(b) Deep
tubewells


2

Recharging
stratas

through rainwater
harvesting methods


(No. of villages of lower range concentration can
be


decreased
)


3

Storing rain water for drinking purpose

(a) In areas where electricity problem is more

(b) In areas where concentration is more

( c) In
areas where
PWS
is uneconomical

(d) In areas where dependable source is not
available

Sumber
: Rain water harvesting,
Gautam

Banerjee
, UP
Jal

Nigam