Effective Rainwater Filter – For rooftop rainwater harvesting – Very low-cost, do-it-yourself filters

[SAMPATH S]

For a large number of urban households, ground water / bore well water is a supplementary source of water to the piped water supply.

For many apartments in the city outskirts and for most of the households where piped water supply has not reached, the main or the only source of water is ground water / bore well water.

However, hardly anyone considers the possible level of contamination (due to bacterial and such others), apart from any geological contamination present in the ground water.

Further, knowingly or unknowingly, agriculturists and urban dwellers let surface rainwater and rooftop rainwater directly into bore wells, both live as well as defunct, thus letting loose severe contamination through the aquifers.

Following are the guidelines issued by the Ministry of Water Resources for ground water recharge structures. Though it looks a bit complicated, it is better to get an overall view of rainwater harvesting, in our own interest.


F.No. T-81011/77/2021 - GW Section-MOWR
भारत सरकार
Government of India
जल शि􀀋 मं􀀎ालय
Ministry of Jal Shakti
जल संसाधन, नदी िवकास और गंगा संर􀀗ण िवभाग
D/o WR, RD & GR
(भूजल अनुभाग / Ground Water Section)
****
Shram Shakti Bhawan, Rafi Marg
New Delhi, Dated: 31/03/2023
To,
The Chief Secretaries/Administrators of all the States/UTs of India. (as
per the Standard list)
Subject:- Prevention of potential contamination of ground water
from Rain Water Harvesting systems in Urban Areas – reg.
Sir/ Madam,
I am directed to invite your kind attention towards Hon’ble
NGT’s observations, expressing concern over Rain Water Harvesting
(RWH) system being one of the potential source of contamination of
ground water in the country. The Principal Bench, Delhi of Hon’ble
NGT, while disposing of matter related to societies in Dwarka area,
Delhi (OA 147/2021), vide their order dated 10.12.2021 directed that at
many places where RWH systems are installed, the same are either not
functional or resulting in contamination of ground water which situation
needs to be remedied not only in Delhi but pan India. This may be
urgently looked into by a joint Committee of CPCB, Ministry of Jal
Shakti (MoJS) and Ministry of Urban Development, Government of
India. MoJS will be the nodal agency for the purpose.
2 . In this regard, a Committee as per directions of Hon'ble NGT
was constituted by this Department which visited selected RWH sites
in 05 States i.e. Delhi, Haryana, Karnataka, Rajasthan and Tamil Nadu
and submitted its report. The committee found that deficiency do exist
in implementation of RWH system at certain places and due attention
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was not given to possibility of contaminants breaching into the RWH
system and eventually finding way into groundwater, particularly where
the harvested water is directly used for Artificial Recharge (AR). From
the report of the committee and their experience gained during site
visits, it is quite likely that similar situations may exist in other States
too. In view of this, a guideline on RWH system and SoP with Do's
and Dont's as per Annexure-I & Annexure-II recpectively are
enclosed herewith.
3. It is requested to kindly direct/ instruct concerned Departments/
agencies to strictly follow the guidelines including Do's & Dont's while
implementing the RWH systems in your State. Further, the concerned
Department/agency in the State may approach Regional Director
Offices of Central Ground Water Board (CGWB) for technical guidance/
support, if any.
4. This issues with the approval of the Competent Authority.
Yours sincerely,
(Rajendra Kumar Sahu)
Under Secretary to the Govt. of India
Ph: 011-23766907
Email: gwdesk-mowr@nic.in
Copy to:
i. Sr. PPS to Secretary, DoWR, RD & GR, MoJS
ii. SPPS to Special Secretary, DoWR, RD & GR, MoJS
iii. Sr PPS to AS&MD, NWM
iv. PPS to JS(A,GW & IC), DoWR,RD & GR, MoJS
v. Sr PPS to Secretary, MoH&UA
vi. PPS to Chairman, CPCB
vii. PPS to Chairman, CGWB


Annexure-I
i. The Committee recommended to give stress on contamination
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aspect while designing and implementing the RWH systems and
suggested for strictly adhering to the BIS Standard - IS
15797:2008 (for implementation of Roof Top Rain Water
Harvesting System in the country) which is a very
comprehensive document (a copy is enclosed for ready reference).
Section 6.5 of the document deals with general ‘Management and
Maintenance’ of the system and Section 7.4 specifically tells about
‘Management of Catchment Area, Drains and Recharge
Structures’. Section 7 provides designs of AR structures suitable
at various different situations.
ii. It has also been suggested to avoid Rain Water Harvesting System
for the purpose of Artificial Recharge in certain urban areas
especially in congested places in the vicinity of sewerage system
components/ landfill sites etc where chances of contamination are
high through mingling of untreated sewerage water/domestic
wastes.
iii. The Committee has further suggested that in case of
small households, cluster based RWH system should be promoted
in place of individual household schemes.
iv. States may promote incentivization for adopting RWH, either in the form of
rebate or subsidy in water-stressed areas.
v. Large-scale RWH system, such as those in large industrial, residential and
commercial complexes, should have piezometer(s) installed at appropriate
site(s) for periodic monitoring of water level and water quality. These
parameters are the most important and reliable indicators of functioning
status and health of RWH system.
vi. The design of RWH should by-pass first roof top harvested rainwater. Mixing
of drain water with rooftop run off or with runoff from paved areas, where
vehicular movement takes place, should be prevented.
vii. As water quality may not be strictly checked, the water stored in harvesting
structures may be used strictly for non-potable purposes.
viii. Concept like RWH Theme Park, Bengaluru may be promoted for proper
guidance to general public/ individual households.
ix. All RWH sites should be geo-tagged for better visibility for monitoring
purpose.
x. There should be mechanism to avoid misuse of the recharge tube-wells for
pumping purposes.
xi. Suitable online filters can be considered in the pipeline to avoid minor
contaminants, if any, while harvesting the rooftop rainwater to the recharge
tube-wells.
xii. District Jal Shakti Kendras may be strengthened and general public may be
sensitised to follow correct RWH system through regular awareness
generation by means of mass media, print media etc.
xiii. District administration may randomly check few RWH sites on monthly basis
and suitable directions/corrective action may be suggested to the owner(s) of
the RWH system(s) and the same may be followed up for strict
implementation post inspection.


Annexure-II
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DOS AND DON’TS WHILE IMPLEMENTING ROOF TOP RAIN WATER
HARVESTING AND ARTIFICIAL RECHARGE
A. While Planning Implementation of Scheme/ Construction of Structures
Dos
Choose the right recharge technique: RWH schemes should have Artificial
Recharge provisions depending upon local hydrogeological/ site-specific
conditions. In this regard, the BIS Standard - IS 15797:2008, for
implementation of Roof Top Rain Water Harvesting System may be referred
to. Section 7 provides designs of AR structures suitable to different situations.
Source Water: Only non-polluted rainwater from the roof tops and other
catchment areas has to be diverted to recharge structure through connection
of downpipe.
RWH/ AR Sites at Safe Distance: Depending upon groundwater flow
direction, RWH/AR sites should be located at safe distance from possible
contaminant source such as sewage drains/ landfill sites/ cesspool/ sewage
system having hydrogeological connectivity with the aquifer.
Insulation from Possible Contaminant Source: There should be proper
arrangements in place to prevent sewage water or contaminated water from
paved area from mixing into run-off/ recharged water.
Provision of Filters: There should be proper mechanism to let the water
pass through filter media before entering into recharge system in order to
minimize the possibility of aquifer material getting choked. Online filters (filters
fitted in pipelines carrying roof top water) can also be used to avoid minor
contaminants, if any, for diverting the rooftop rainwater to the recharge
tubewells.
Provision for By-pass of First Flush: RWH system should be designed in a
way to allow by-pass first flush (first rainwater).
Provision for pre-treatment of water: The Water should be pre-treated to
remove suspended solids, organic matter, and other contaminants before
recharge. This will help prevent clogging of the recharge structure and
protect the groundwater quality.
Dual pipe system for utilization of harvested water: Dual pipe system
should be
installed for utilization of harvested water for non-potable purposes, i.e other
than drinking, cooking and bathing.
Cluster-based RWH System: In the areas of only small households,
cluster-based RWH system should be promoted in place of individual
household scheme.
Installation of Piezometers: Large-scale RWH system, such as those in
large residential and commercial complexes, should have piezometer(s)
installed at appropriate site(s) for periodic monitoring of water level and water
quality. These parameters are the most important and reliable indicators of
functioning status and
health of RWH system.
Geotagging of RWH/ AR Sites: All RWH/ AR sites should be geo-tagged for
better visibility for monitoring purpose.
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Don’ts
It is better to avoid RWH/ AR in areas having shallow ground water levels
(say shallower than 5 metre below ground level (mbgl).
Recharge should be avoided in areas where there is possibility of
contamination of
groundwater. RTRWH with AR in buildings such as hospital buildings may be
avoided. In such cases storage of rainwater for non-potable uses should be
encouraged.
There should be no mixing of drain water with rooftop run off.
Run-off from paved area having vehicular movement should not be diverted
towards RWH system.
RWH/ AR sites should not be located in the vicinity of possible contaminant
source such as sewage drains/ landfill sites/ cesspool/ sewage system
having hydrogeological connectivity with the aquifer.
Contaminated water should not be recharged as it can pollute the
groundwater and make it unfit for human consumption.
Domestic waste water should not be diverted directly to Recharge Pits,
particularly in areas where water levels are shallow.
Recharge wells should not be constructed beyond water level. Direct
recharging below water level should not be done.
Recharge structures should not be constructed in areas prone to flooding as
they can be damaged or washed away during heavy rains.
Recharge should not be unplanned. Unplanned recharge can lead to
groundwater contamination, soil erosion, and other environmental problems.
B. Maintenance and Monitoring of RWH/ AR System
Maintenance of recharge structures is important to ensure their long-term
effectiveness and sustainability. Here are some key maintenance practices that can
help keep recharge structures functioning properly.
First flush should be by-passed.
Rooftops should be cleaned regularly.
Filter material should be regularly cleaned/ replaced.
Sediment and debris can accumulate in recharge structures over time, which
can clog the pores and reduce the infiltration capacity. Regular cleaning can
prevent clogging and help maintain the recharge capacity of the structure.
Regular monitoring and inspection of recharge structures can help detect any
signs of damage, erosion, or clogging or damage early on, before they
become more serious. This can include checking for cracks or damage to the
structure, as well as monitoring the inflow and outflow of water.
Water level and groundwater quality around the recharge structure should be
regularly monitored through purpose-built piezometers.
Monitoring mechanism should be effective through involvement of officials
trained to evaluate functioning of installed RWH system as per BIS.
Any damage or erosion to the recharge structure should be repaired
immediately to prevent further damage. For example, if a recharge well has a
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crack or a hole, it should be repaired as soon as possible to prevent soil from
entering the well and clogging it. Prompt repair and maintenance can help
prevent further damage and ensure the long-term effectiveness of the
recharge structure.
Vegetation can grow around recharge structures and block the inflow of
water. Regular trimming of vegetation can help maintain the flow of water into
the recharge structure.
Keep a record of maintenance activities and observations for each recharge
structure. This can help identify patterns or trends in maintenance needs and
guide future maintenance activities.
Don’ts
Do not dump pollutants or waste near or inside the RWH/ AR structure.
Never leave the covers of RWH chamber/ AR structures open.
Do not allow wastewater to flow towards RWH/ AR structures.
C. Other Suggestions
Underground Storage tank/ sump, made using cross-wave technology or
uPVC pipes saves space, besides providing strength to the structure. As it is
costly, the technology may be used in large Government Buildings,
commercial complexes and industrial premises.
In the new buildings, the complex is divided in a way to have alternate bays
for sewage and RWH channels.
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[SAMPATH S]

Despite El Nino cloud, IMD predicts normal monsoon

https://www.deccanherald.com/national/despite-el-nino-cloud-imd-predicts-normal-monsoon-1222065.html

Enough reason to harvest pure rainwater.

[SAMPATH S]

Sewage mix in ground water. Rooftop rainwater properly stored and used is always a superior option.

The New Indian Express.jpg (93.51 KiB) Viewed 80245 times

[SAMPATH S]

Huge ground-water extraction by humanity. Where is the earth heading?
Read about this and also view the video:

https://www.indiatoday.in/science/story/earth-pole-moved-spin-nudged-groundwater-pumping-india-2394793-2023-06-19

https://youtu.be/tPnuboGyReU

[SAMPATH S]

Contaminated water supply in Bengaluru is reported frequently from one are or another.
Here is an incident reported in the posh Indiranagar and sourrounding areas:

https://www.thehindu.com/news/national/karnataka/indiranagar-residents-being-supplied-with-contaminated-water/article67008894.ece

All the more reason to store and use pure rooftop rainwater.

[SAMPATH S]

Ground Water crisis acute in Karnataka - Even Rains don't help - A very detailed article covering the whole gamut of water availability in Karnataka.

https://www.deccanherald.com/specials/insight/even-rains-don-t-help-groundwater-crisis-acute-in-karnataka-1233062.html

[SAMPATH S]

New Indian Express 17th July 2023

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[SAMPATH S]

The New Indian Express 22.02.2023.jpg (135.89 KiB) Viewed 75392 times

[SAMPATH S]

I would be shortly completing my 9th successive successful year in exclusive use of rooftop rainwater for all domestic requirements, round the year.

To mark this occasion, I have arranged for a demo of my Effective RWH Filter System and the associated arrangements for successful implementation of RWH, at my residence, on Sunday the 5th November 2023 at 11 a.m. Further, doubts if any would also be clarified. Those interested in participating may confirm same at the earliest.

Location would be informed individually on confirmation of participation.

Arrangement limited to maximum of 5 participants, hence first come first served.

Non-members may send their confirmation on my email id - sampaths144@gmail.com.

[SAMPATH S]

WORLD WATER DAY 2024

Every year, 22nd March is observed as World Water Day.

The theme for this year’s World Water Day is “Water for Peace”. Be the change you want to see in the world. You can make changing the way you use, consume and manage water in your lives.
Water touches the life of each and every human being.