Here, in Pakistan, I have noticed there is no consideration for groundwater pollution, when constructing a toilet.

Pawan: You have a good point - creating groundwater pollution in an rush to end OD.

F H Mughal

That's true, Pawan, but the discussions on the definition of "safely managed" sanitation (under the words used in the Sustainable Development Goals) seem to prioritise systems which contain the faeces, which suggests to me that the JMP are thinking hard about the risks of contamination of groundwater.

But you make a very good point in that the rush to "end open defecation" could indeed lead to an increase in technologies which might actually increase the risks to health.

To me the whole thing seems very confused.

Dear Mudgal and All

There are several reports on contamination of ground water due to leach pit toilets. Such contaminants are mainly pathogenic bacteria and nitrate. There are different opinions of degree of contamination- travel of contaminants in soil. It varies mainly with the nature of soil and hydraulic loading rate in and age of pit latrines. Of course, flow of ground water is also one of the factors. But it is only for academic point of view. A household going for defecation in open should not be expected to know all these factors before construction a toilet.
Even knowing such disadvantages with leach pit toilets, the “technology” is being implemented in many developing countries with the financial support from the respective governments and international funding agencies.
WHO/ UNICEF have defined a sanitary toilet, having safe confinement of human excreta. Leach pit toilet with cover pit is categorized under sanitary toilet. Perhaps such definition is based on the physical confinement of human excreta. Contamination of ground water or surface water has been overlooked.
There are some areas in India where ground water table is only a few feet and such leach pit (single or double pit) toilets are implemented in a large scale. The technology may help to eliminate Open Defecation but for future this may result severe ground water pollution causing irreversible and more adverse affects on health than open defecation.
WHO/ UNICEF and other international agencies should redefine sanitary toilets, also taking into consideration of possible ground water pollution from the technology.

Regards

Pawan

Publication by British Geological Survey is useful and interesting. The publication provided by Sudhir is also very useful.

I'm afraid, I could not achieve much success with “SanitContam”
Aren't there any publications that go with this tool?

F H Mughal

WRC Research Project 2115/1/15

Title: Investigation into Pollution from On-Site Dry Sanitation Systems

Authors: Lorentz, Wickham and Still

WRC Manager: Jay Bhagwan

A literature review can also be accessed in the document.

I sat on Reference Group for this project. Hypothesis that pollution spreads from pit-type sanitation solutions was tested. Results must be viewed with respect to soil and geology in that study area (KwaZulu-Natal). Important was development of methodology for testing hypothesis - could be used by others.

Regards
Sudhir

Hi my colleagues,

I recently came across the tool “SanitContam”, developed by INREM Foundation in 2011:
www.inrem.in/project_sanitation/tool_sanitcontam.html

This is a simple Excel spreadsheet model. Any thoughts about it?

I will look at it in detail and later on we can comment.

Cheers,
Miguel

Dear all:

The British Geological Survey published a useful manual on this topic about 10 years ago, under the project Assessing the Risk to Groundwater of On-Site Sanitation (ARGOSS). www.bgs.ac.uk/research/groundwater/Argoss.html

The manual was field-tested in Bangladesh and Uganda. As I recall, the soil conditions were important drivers of safe distance. Also it's important to consider the depth of the wellscreen as vertical distances as horizontal ones contribute to pathogen attenuation.

Rick

Dear Rajiv,

from CSIR or WRC end 90's
All "water"-NGO's in RSA used it.

It needs a search by a RSA water-NGO insider. I regret, outsiders would not get access any more.

Anyway, this old software will not end poverty-apartheid and some related environmental problems.

Regards,
Detlef

Dear AquaVerde,

Would you by any chance be able to indicate year of use, name of software, developer name, etc.? And was it from WRC?

Just to narrow down the search. It would help.

Rajiv

Dear Kanalwolf et al.,

thanks for the input; the 50-days rule is also applicable in the European Union, as far as I do know. Anyway, apart from good practices in well construction - these are really well and long-term established standards...-, the behaviour of virus might be very different from the behaviour of bacteria -as e. coli- in groundwater.

We should be careful on judging on transport of organic matter and bacteria around newly built wells and wells approaching their mid-term life expectance (i.e., from 10 to 25 years) since around older wells we might find well-established bodies of organic -living- matter of algae and bacteria forming organic fleeces around the well and possibly enabling e. coli and other not-so-harmless bacteria to reproduce, spread and survive longer in groundwater. Evidence for this is known, e.g., from the spread of f. cholerae in the Sundarbans in India and Bangladesh, where even seasonal influences as algae growth in rivers at the inset of the monsoon have their effect on bacteria inside wells fairly distant from these rivers.

Again, wells built following the established standards are the first and best protection against groundwater pollution through organic matter - and only samples taken from such wells allow hydrogeological guesstimates (or better) of transport distances and possible spatial extensions of plumes of pollution and transport velocities. All data taken from wells not corresponding to such standards, such as I mentioned from Sindh, just display faecal contamination or -generally- organic substances in the groundwater around these wells, without allowing judgement on the source of contamination itself.

Best regards,

Jürgen

Good point, Detlef, I hope someone will find this document/source.

I will be most happy to have a look at this "wheel" and see if it is still rolling, once it surfaces again.

So many good thougths have been thougth already, but we need to polish them once in a while (and put this on websites like SuSanA), otherwise they get lost.

Kind regards,
Leif

Dear Leif,

Actually, i would think that it could be a good idea if SuSanA would gather some key information on well siting and seperation distances adapted to low tech environemnts in a kind of factsheet document

above I mentioned a little program from WRC "Made in South Africa" from the end 90', the results of it been: "separation distances adapted to low tech environments in a kind of fact-sheet document" based on various soil conditions.

Maybe some SUSANA-colleagues could "dig" the nice document/program out at WRC (www.wrc.org.za/) by using own informal connection to the Commission, instead of SUSANA is "inventing the wheel again".

If I remember well the established "50-days-rule" is applied by this little WRC-program too.
In Germany this "50-days-rule" is still the first starting point for any well-plannings by DIN (German Industrial Standard)

Best egards,
Detlef