Dear Mr. Paresh,

Please have a look at 2 blogs at these links, and one attachment. You will enjoy reading these blogs and the attached publication:

blogs.worldbank.org/water/fecal-sludge-m...developed-tools-help

blogs.worldbank.org/water/5-lessons-manage-fecal-sludge-better

Regards,

F H Mughal

Thanks for the detailed explanation, it is very helpful.

paresh wrote: I am aware that more people are connected to on-site systems and they are looked as stop-gap arrangement while engineers and planners prefer sewerage system.

Realistically speaking on-site sanitation will stay the defacto standard in most places for the foreseeable future, therefore the need for FSM. But my impression is also that many engineers only prefer sewerage systems because that's what they learned in university, and often they also don't consider the necessary construction of a large sewerage treatment plant to be "part of the deal"...

paresh wrote: I am currently doing the task but haven't found anything on why FSM needs to be prioritised over effluent and greywater. In some places, the septic tanks are over sized and hence not emptied for many years. The question which arises is what is the problem if septage remains in tank for long duration besides the fact that it starts hardening thereby reducing effective size of the tank.

Besides that it is a myth that many tanks are oversized (people don't sufficiently consider the necessary hydraulic buffer and that tanks are already technically full when the sludge & scum occupies some 2/3 of the available volume), you need to stop thinking of individual tanks and see it as a city wide problem. Then there is always quite a lot of tanks that would benefit from emptying. And of course if you want to avoid sludge hardening, emptying more often is also a good soluntion.

paresh wrote: One is trying to understand why FS which needs to be treated only when tanks are emptied (this is not frequent) is getting attention while effluent from septic tank and grey water which is a daily outcome is neglected, is it that the concentration of pathogens is higher or any other reason?? . This is also going to be an obvious question from jurors who may not be experts in the field.

Regarding the frequency see comment about city wide scale above. Grey-water is basically not a major issue pollution wise as for most households it is a low-strength, low volume, few health issues problem.
For septic-tank effluents: The problem starts in the tank, the need to treat the sludge is actually a secondary result of the necessary emptying. Assuming a reasonably well constructed multi-chamber septic-tank additional secondary effluent treatment is only necessary in densely settled areas (with shallow ground water abstraction) or for environmental reasons to reduce the nitrogen/phosphorus pollution load.
However as soon as the tank is not emptied early enough (=FSM) this turns around and then (and only then) the effluents become a real pollution problem. And in addition any secondary effluent treatment system will be quickly overloaded and damaged.

I would suggest that you stop by the SuSanA library and search for FSM related publications. There are several available in there for free download.

Good luck!

Thanks. That was the first thing I read

Thanks for a quick reply.
I am aware that more people are connected to on-site systems and they are looked as stop-gap arrangement while engineers and planners prefer sewerage system.

I am currently doing the task but haven't found anything on why FSM needs to be prioritised over effluent and greywater. In some places, the septic tanks are over sized and hence not emptied for many years. The question which arises is what is the problem if septage remains in tank for long duration besides the fact that it starts hardening thereby reducing effective size of the tank.

One is trying to understand why FS which needs to be treated only when tanks are emptied (this is not frequent) is getting attention while effluent from septic tank and grey water which is a daily outcome is neglected, is it that the concentration of pathogens is higher or any other reason?? . This is also going to be an obvious question from jurors who may not be experts in the field.

PS: It was only a humble request to suggest literature, not do the review for me.

Thanks

Hi,
In addition to JK's points above, I would recommend that you start by reading the Faecal Sludge Management book by Sandec/Eawag and UNESCO-IHE since it gives a good over view of the state of FSM globally, especially the first chapter. The book can be downloaded in the SuSanA library: www.susana.org/en/resources/library/details/2100

Regards,
Daniel

Who told you it is? If you look actual investments and construction projects I would wager that FSM is less prioritized at least by a factor of 10:1 (and probably even much more).

If your actual question is why it *should* be prioritized (but isn't), than that is easy: any sanitation coverage figure will tell you that globally much more people have on-site sanitation than are conected to a sewer system.

P.s. the purpose of such a home work is doing literature research, not asking other people to do the work for you

P.P.s.: if you are referring to effluent from a septic tank and not a sewer system, than again it isn't really. But I agree that this is probably a bit of an overlooked topic... but a full septic tank without good effluent treatment is much worse than an regularly empied one without.

Hi All.
Need a little help. Doing literature review of FSM for as a part of coursework at IIT-Bombay, India. Need to understand why FSM is being prioritised over effluent and greywater treatment.

Request to share relevant literature.

Thanks
Paresh