As a common trend these days, any alarming occurance in the city is responded with some knee jerk reactions. It can be traffic issues or frothy waterways which CATCH FIRE!
About the ailing Bellanduru lake, the 'officials' suddenly woke up and have said that all appartments, irrespective of number of dwellings(current limit is above 50 houses), will now be asked to have an STP..and with this they think the frothy lake can be saved..
I would seriously want them to first assess how the STP's are functioning in the other large/reputed appartments clusters..
There are currently many issues around operating a STP successfully:
- Waste/sludge disposal is a problem. A working STP is heavily dependent on the sludge being cleared regulalrly and finding resources to do that is difficult.
- Equipment maintenance is another pain point. Frequent break down of the heavy duty pumps is a problem and getting personel to repair it is tough
- Costs involved with all this is prohibitive and hence appartment complexes usually have defunct STP's after the initial few months/years
Unless the PCB and other govt bodies can work at solving issues with the current STP setup's, they will never be successful in keeping the lakes clean at all!
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decentralised plants, perhaps the answer
DEWATS (Decentralized Wastewater Treatment Systems) representing a technical approach rather than merely a technology package, and requiring low maintenance, can perhaps provide the answer.
Check the following video presentations:
1) Animation film showing the processes involved (click here - 2 mins)
2) Typical plant operating at the 725 bed (+ accommodation for staff, and visitors) Aravind Eye Hospital near Pondicherry (click here - 12 min, 30 secs)
Consortium for DEWATS Dissemination (CDD) Society has a base in Kengeri, Bengaluru (bangalore@cddindia.org), which operates a demonstration plant at the site.
May be Prajagalu could organise a visit.
govt help?
Can the govt help to take the sludge out of appartments..to probably centralized plants where it can be reused to do composting and/or generate bio-gas..
Think a good working model for this is needed to help the comunity and inturn save the lakes!
sludge not necessarily a problem
If I understand correctly, the CDD demonstration plant in Kengeri has a regular arrangement with a BWSSB contractor, who sends his vehicle to pick up the sludge (vacuum suction), on short notice. And, after drying in yards outside the city, the sludge turns into valuable bio-fertiliser which has a ready market among the vegetable and other cash crop farmers. As such, I don't think sludge is a serious problem.
Yes, there's a bit of organising and monitoring work involved. But, once streamlined, it should be far more cost effective (apart from being environment friendly) compared to the traditional aerobic STP's, both installation-wise and operations-wise.
It would be interesting to check out if any developers have given thought to it. And, if not, why not?
Sludge handling - feasibile?
As of now, I think viability of converting sludge to fertilizer is the concern as conversion /handling /transportation of sludge is costly & may not yield enough returns to make them cost efficient.
If housing societies manage their own wastes & use them internally, at least transportation costs would come down drastically.
water is used..
Yes Naveen, the processed water is used for tasks like watering gardems etc..but the sludge is not used..unlesss we can have setup like what Murali sir mentions
Some where City planners and BBMP used law for their non respon
When BWSSB can operate 10 MLD / 20 MLD capacity STP for individual houses.
When it comes to Multi story complex / apartments, making mandatory STP has ensured BBMP and BWSSB washing their hands.
As city expanded raipdly over last 15 years, laws were made to ensure BWSSB or BBMP work comes down even after collecting taxes.
Where ever dense population is allowed with multi story or higher FSI , city planners or BBMP or BWSSB should look into how much water consumption or supply of fresh water and direction flow of rain water. Based on this they should have mini STP plants of 5 MLD so that treated water can recharge ground and sludge can be taken out by the contractor and sell as fertilizer after processing.
Presently I see Yelahanka - Allalsandra lake gets water from BWSSB STP, down stream is Jakkur Lake gets water from BWSSB STP at Jakkur. Sludge is taken by the contractor.
After Jakkur lake downstream is Rachenahhali lake which gets excesss water from Jakkur lake. Now all these lakes r full with boundary well defined ( may be earlier some encroachments exists on the lake boundry. )
In all three lakes, interconecting chennals are badly damaged and even exit of Rachenhalli lake is completly choked by not maintaining at all, Channel area has been reduced to just 5 / 10 feet by BBMP and BDA who r the culprits.
Also their is one more upstream STP at Hebbal which feeds water to Lumbini Garden.
Now downstream of Rachenahhli is really bad and it goes via Banaswadi and Kalkeri on Hoaramau Road and further goes to Whitefield area.
Same thing with Belandur Lake. : Water from Indiranagar Old Airport Road, HAL township, HAL Airport, KGF golf ground, Doamlur all gets into Belandur without any treatment.
HAL may be culprit in this as 2000 acers of HAL airport rain watre is not harvested and finall enters to Belandur lake thru the sweage. Same thing with KGF golf also.
Also Indiranagar area does not have itself BWSSB STP. So the Belandur lake gets all the stuff from surrounding area.
need for sustainable solutions
Work on 10 other STPs, construction of which began in various months between 2010 and 2011, will be completed by end of 2015, he said. “When completed, they will be able to handle 339 MLD of sewage water,” he added.
An estimated 1,500 MLD of sewage is being discharged by residents of Bengaluru daily. “The total capacity of existing STPs of the water supply board is only 721 MLD,” he said. Hence, the remaining sewage gets discharged into other water bodies polluting them.
When the ongoing and proposed STPs are in place, Bengaluru’s entire sewage can be treated at the plants. “We are now working on setting right all the missing links in connection with the STPs,” Parwez added.
For the full text of the report in the New Indian Express, click here.
The problem, if I understand correctly, is the incapacity of the BWSSB to pay the huge BESCOM bills for the operation of the STP's, on time, and BESCOM's cutting off supplies to them, thereof, leading to the STP's having to discharge untreated sewage directly into the water bodies. As such, I wonder if adding STP capacity is going to solve the problem.
This is apart from the other major problem of raw sewage being reached to the STP's, through the network of storm-water drains criss-crossing the city, and raising a stink all through, literally.
And, this is perhaps where the low energy, de-centralised DEWATS model could come in. May be start with a pilot in a gated community/ layout that's being developed, and based on the learnings (in fact, there are working models already, like the one in Aravind Eye Hospital, near Puducherry - check my post of 23rd May, scrolling above), replicate it across the city, even retro-fitting it in established layouts, where feasible.
The current practices are plainly unsustainable, and, as such, we have no choice other than to look for better options, and quickly too.
the dire need
It can be concluded that sewage cannot be prevented from entering Bellandur lake in the foreseeable future. The technology is available but the expense involved in prohibitive and BWSSB is highly unlikely to receive the necessary funding from the government or the public.
For the full text of the report in the Bangalore Mirror, click here.
All the more the reason why alternate approaches have to be looked at. And, there's no time to lose.
The Dire Need - another thought!
How about putting a price on the sewage that each household generates rather than on the amount of water consumed? It would mean more revenue collection by BWSSB which means it could put up the funds for constructing and maintaining STPs with commensurate capacities?
Let there be a meter placed at the outlet of each domestic sewage line and household charged according to the volume it generates for treatment. After all our major problem is water bodies getting polluted, for which the remedy is to have treatment plants. The capacity of STPs ought to be in line with the amount of sewage being created, and each household contributes to the total volume. Therefore each household must take the responsibility for creating this problem. Now BWSSB is collecting money only for providing water, but the discharge of effluents is not dependent upon only the water supplied by the board, but there are houses and colonies/layouts that are totally dependent upon underground water sources and they too produce effluents.
Those who dont pay, cut off their sewage line from the main line. That would be a strong deterrent for defaulters. BWSSB gets additional money for creating sufficiernt capacities, water bodies dont gert polluted, ground water recharge takes place and Bangalore has more water reserves.
The present practice of charging sewage rates is imperical and has no structure.
how to measure?
@ Major - I am not sure there are effective ways of measuring sewage at house-hold levels.
Include cess with property tax
I agree with Mr Murali - sewage at house-hold levels cannot be measured as it does not flow under pressure but just drops into wide bore sewers.
Best to include a sewage cess with property tax.
Isnt BWSSB already collecting
Isnt BWSSB already collecting seweage cess?
Guess most of it goes in SWD dredging etc where they have mistaken the ' S' for Sewage instead of 'Storm'!
Hope they can bring some order there and use the money more efficiently..appartments sewage needs differential treatment because of it volume as it enters the manholes..so possibly there can be differential costing on the sewage cess too..
But I think raising money should not be difficult, its how it is used which could matter most!