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Waste Water Management (WWM)
Written By psaram42 - 26 June, 2009
Bangalore Analysis sewerage waste water treatment
Water-carried wastes, in either solution or suspension form, that flows in sewage pipes from any house hold, commercial enterprise or an industry is called waste water in general. If it contains mainly human excreta and other organic matter it is called sewage. This sewage with Human excreta and other organic waste is not a waste in the real sense, as it contains recyclable soil enriches called manure and fuel for generation of electricity. This kind of waste from house hold or hospitality industry can be classified as sanitary water discharge. This discharge water is characterized by its physical condition, its chemical constituents, and the bacteriological organisms that it contains. Thus depending on their origin, wastewaters can be classed as sanitary, commercial, industrial, or surface runoff. Industrial waster water can be of different grades like A, B and C. The A grade Industrial wastes being the most dangerous and unacceptable and those Industries producing “A” grade waste water are to be banned at best.
For details of known Sewage treatment, or domestic wastewater treatment, procedure here is a Wikipedia Link.
It is important to note that in a city like Bangalore Sewage ie domestic waste water is disposed using the sanitary (sewage) pipes, to be delevered at the treatment plant. These pipes mostly made out of vitrified porcelain of 6 inches or more diameters. The volume carrying capacity of these pipes is squarely proportional to its diameter. Therefore if the volume exceeds the limit there will be backlog resulting in spillage of the man holes. If this spillage can find its way to storm water drains and or the sewage is directly let into storm water drains, by design leagally / illegaly the result will be pollution of the lakes into which these storm water drains are currently designed to discharge. This aspect has already been discussed briefly in an earlier thread.
The SWD Planning aspects have been discussed elsewhere in PRAJA, where a new system being used in other developed countries like Great Britton, Australia and USA etc was discussed. That design philosophy is entirely different, than that existing at present in Bangalore. This new (as far as Bangalore is concerned) philosophy is to use the storm water to charge the ground water table at the rain fall site directly. This is no doubt an alternate system than that being used currently in our city of Bangalore, which is to use the lakes for storing the rain water on surface instead of charging the under ground water table. Thus the crrent technology happens to be the oldest technology of Roman origin. However let us be clear that what is discussed in this thread is not the design philosophy of SWD. Please do not discuss SWD here which will only confuse the issue being discussed here viz domestic wastewater management. For this to take place the sewage water has to be carried up to before delivering at the treatment plant by proper sized pipes. There should be no spillage till the delivery at the STP.
Unfortunately here in Bangalore the SWD design philosophy so far has been to collect all the storm water for discharging into designated Lakes, with no ground water charging at all. So at preset in Bangalore these Drains are supposed to discharge the rain water to particular designated lakes. These are many times open drains at many locations.
The concept of ground water table charging directly at contiguous catchment’s locations is attractive too, on the other hand. No doubt it should be examined. This is addressed in a different thread. Not here please.
COMMENTS
psaram42 - 30 June, 2009 - 09:02
Your statement and definition of 100% sustainable is perfect. It is Fantastic. I agree with your definition, sir.
psaram42 - 26 June, 2009 - 10:21
The existing twin KC Valley plants are treating about 250 MLD sewage water from some places in the KC valley area.
It is known that the Lake has several other inlets (SWD) which discharge untreated sewage water into the Bellandur Lake, as reported on Praja earlier. Mr. RK Chari has suggested that the above culprit inlet water can also be treated separately before being discharged in to the lake. This extra requirement however has to be brought to the notice of the authorities concerned.
RKCHARI - 26 June, 2009 - 12:09
The above comment by Mr. Ananthram is substantially correct. The objective of every Municipality should be to recharge ground water table in the first instance. Rain also falls directly into open lakes. Given Indian public health conciousness, open lakes are more a health hazard than beauty spots unless the authorities maintain the lakes as a recreational spot. That too can be done with crystal clear water for sports purposes, but that requires a people friendly Government.
By avoiding open storm water drains, covering it with permeable pavers with a holding, yet infiltrating tank underneath, rainfall gets temporarily collected in these underground tanks on either side of an existing road. I say temporarily because the tanks come with a mechanisim which enables storm water to get absorbed to ground water table levels in a more gradual and in a disbursed manner. Consequently storm water does not have to "go anywhere".
The technology is not expensive nor it is complicated. Moreover there is no maintenance whatsoever. Additionally, Municipalities can also plan to re-do roads (at least the smaller 30 to 40 feet ones inside colonies - the various crosses and mains) with ecologically sustainable road surfaces all of which will act as absorbent surfaces when rain falls. So there will never again be water logging on these roads, no open drains and lots of additional space to grow trees, grass and other green shrubs etc.
Is this a dream? No, absolutely not. Can be easily achieved if there is public support and Government will to make life comfortable and pleasant for its citizebry. Ironically, only today the newspapers announce that the State Cabinet has sanctioned Rs. 150 crores for "tackling the storm water menace"!!
Best wishes,
R.K.Chari
psaram42 - 28 June, 2009 - 15:32
“Several thousand miles of such ecologically sustainable roads dot the world over - even in countries like Indonesia and Malaysia.”
Yes why cant us? I sincerely hope we in India pick the thread at least now, to have the benefit of this proven technology without wasting any more time. I believe the present Karnataka government has allocated Rs 15 Million for remodeling storm water drains. Let us Hope for some positive output at least now.
RKCHARI - 29 June, 2009 - 12:40
Dear Suhas,
Retrofitting according to our parlance means removing existing raod (tar / bitumen / asphalt etc) and re-doing it with drainage cells and underground tanks. The solution provider normally offers the innovative technology on a turnkey basis wqhereby their cost includes all the digging up and refitting charges on a lump sum basis. It really is very hard to figure out how much it costs on a per square kilometre basis. Each condition of retrofitting varies and the price would therefore not be a standard rate. In some places one may need a single layer of tanks while in others double or even triple tanks may be required. Smaller lanes may do with pervious pavers / drainage cells alone with tanks on either side like swales.
But I can tell you with absolute certainty that if one ways the pros and cons and calculates the life of innovative technology roads with conventional roads, the innovative ones will win hands down price-wise. If you take into account the fact that these new types of roads are guaranteed to last for minimum period of 10 years without any repairs / pot holes whatsoever (and in the very unlikely event of such a thing happening, the promoter replaces it free of cost!), I do not think continuing to pay peanuts for monkey solutions is worth it.
On another note, regarding the existing tendering process, please remember that international companies do not care about actually getting themselves Registered with the appropriate authorities. If they are invited to quote through a formal RFQ they will participate. Otherwise they are not going to grease some palms to be get themselves graded as "A" grade or Class 1 Grade contractors. We are ultimately the losers in the name of Government spending being transparent and politicians and bureaucrats not getting a chance to be finger pointed against.
So I would suggest no purpose would be served to upgrade Government standards to include innovative technology from the world over unless the very system is changed and open invitations to quote without preconditions are floated on a global basis. If indigenous contractors' jobs require to be safeguarded, so be it. Just let us all learn to live with sub-standard roads.
Chari
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