This document discusses decentralized sewage treatment plants (STPs) as an appropriate solution for managing increasing sewage loads from urbanization and population growth. It notes that currently only about 35% of sewage in India's cities is treated, and decentralized STPs can help address this by treating sewage locally. Decentralized STPs return treated water that can be reused for non-potable needs like flushing and landscaping, recycling up to 40% of water usage. The document provides examples of decentralized STP installations by Enzotech Solutions in an office complex and hospital that treat sewage on-site and reuse the water.

1. An Appropriate Technological Solution for Sewage
Treatment -
Decentralized STPs
Workshop cum Training program on Promoting water
use efficiency across urban water sector
Bangalore
13th Dec 2013

2. WATER : What is the issue?
• Economic growth : without
corresponding infrastructure
• Urbanization
– Increasing density of population in
cities/towns – apartments/commercial
buildings
– Expanding peripheral areas :
Bangalore – new areas developing!
• Huge increase in water
consumption Where is the water
coming from ?
– Rivers, Lakes, Ponds …..and now,
mainly Ground water!

3. WATER : Next issue!
• Sources of water drying up
• A larger issue coming up –
– Contamination of Water Sources
• The way we dispose
off waste water is the
biggest issue in water
management!

4. Report Summary
• Citizens’ Seventh Report on the State of India’s Environment,
“Excreta Matters: How urban India is soaking up water,
polluting rivers and drowning in its own excreta”
– by Centre for Science and Environment, New Delhi
• Report released in May 2012 – covering 71 cities of India,
research over 3 ½ years
• The report spells out a six-fold strategy for managing water
and waste in its last chapter
“The agenda for water to water”.
Source : http://www.indiawaterportal.org/post/26422
and http://cseindia.org/userfiles/excreta-matter.pdf

5. How big is the waste water problem?
• Total sewage water in Class I and II Cities India
– 38254 MLD
– Only 11787 MLD (35%) Capacity to treat
– Actual treated – only around 8250 MLD (22 %)
• Current Scenario
–
–
–
–
–
Increase in demand and cost of water
Stringent waste water disposal norms
Increased contaminants from industries
Urbanization leading to large Sewage generation
Untreated sewage leading to severe water pollution
- severely impacting ground water availability & quality.

6. What is “Decentralized” sewage treatment?
• Current system : sewage is the
responsibility of the Government
/ public authorities
• But – how can public authorities
manage :
– Cost : widely spread out
“development”, apart from
untenable economics
– Pipe connections
– Land availability – for “centralized”
treatment plants
• On-site, Local Treatment –
“Decentralized” STP Gives water
back for reuse. (40% of all water
requirement)

7. Recognize and manage Sewage
• Recognize and manage Sewage :
78 % officially not treated and let
out into rivers, lakes, ground
– Sewage generated = 38,255 mld
– Capacity to treat = 11,788 mld (30%)
– Sewage actually treated = 8,251 mld
(22%)
• Improper Sewage disposal - the
dangers : Spread of disease,
contamination of soil and pollution
of ground water
• Quote from Report :
“Sewage must be our obsession”
• Quote :
“Mantra is Decentralization”

8. Why Decentralized ? Local benefits!
• On-site treatment and
discharge
– Reduces load on existing
sewage system
– Local treatment and discharge –
protects contamination of
water sources (rivers, water
bodies, ground water)
• Domestic Water consumption
: Over 30 % for flushing,
washing facilities etc – NON
CONTACT applications
– Suitable for RECYCLED water

9. Urban reuse of water
• Current cycle :
– Ground water -> Usage -> Sewer system
-> Water bodies/environment disposal
UNSUSTAINABLE !
• Required cycle :
– Less ground water -> Less usage -> TREATMENT-> Recycle for
non-potable applications
-> Recharge of ground water / safe disposal in water bodies
or environment
• Rain water harvesting – good start.
However -> Sustainable water management :
only thru Recycling of waste water

10. Average water consumption Per person
Drinking
Cooking
Total
5
5
10
7%
Bathing
Washing Clothes
Utensils washing
Total
55
20
10
85
63%
General washing
Toilet Flushing
Total
10
30
40
30%
Grand Total
135
Recyclable – about
40 % (including
Gardening etc)

11. ONE IMMEDIATE SOLUTION
RECYCLE WATER
At least 40 % of Water usage in urban areas – flushing /
landscape maintenance / facilities washing
This 40 %+ water can be reclaimed and reused!
Leave behind good water
for the generations to come

12. Enzotech Solutions : Credentials
• Started in 2006
• ISO 9001:2008 certified company
• Strong client roster – testimony to efficacy of Patented
technology.
• Over 150 Installations all over India. (A few in Africa)
• Starting Aug ’11, taken over by a team of seasoned
management professionals
• Full fledged operations : Design and R & D – Manufacturing
– After sales support

13. An illustrative Case Study –
Office complex, Chennai

14. Office complex – reuse for flushing
• Office on Velachery Road
• Around 300 people – daily consumption of around
12,000 Litres
• Used primarily for flushing toilets, washing hands
etc.
• Entire water is now treated and reused for flushing

15. Office complex : progress

16. Final position – STP with recycling system

17. The Enzotech treatment process
• To trap large objects
Bar Screen
Sewage
treatment
Tertiary
treatment
Treated
water
• Biological process
• Underground installation
• Sand & Activated Carbon filter
• Ultra Filtration
• Ultra violet treatment – Online
• Flushing of toilets

18. Water treatment and recycling in a
hospital

19. Issues faced by hospital
• Sewage generated was clogging up sewage lines
• Water consumption of 4.5 Lac Litres per day
• Space available for the STP was right next to the car
park
• Post STP installation :
– Treated water used partly for flushing
– No issue of clogging sewage llines

20. Hospital installation

21. Right next to the car park…

22. EnzoMBBR system

23. A typical EnzoMBBR plant – with
Fibre Reinforced Plastic (FRP) tanks

24. Thank you