Dear Asif

We are currently monitoring near-surface water and groundwater near pit latrines and would be very interested in your results. Are you able to share these?

regards

Simon Lorentz

Dear David,

I like your research work, my research some like that.I had research on Ground water quality and pit latrines in a rural area. I found the water was contaminated and most of the people had water born diseases in the area.

Thank you for sharing your research work.
Wish you best of luck in future.

Regards
Asif Khan

Hi all

I did a simple study monitoring groundwater contamination from pit latrines in a sandy aquifer ten years ago (see attached). In that case we found that the pollution plume was limited to just a few metres around the pit latrine.

Soil hydrology is very complex due to the often non - homogeneity of in-situ soils. However, one of the oldest methods of water disinfection is the slow sand filter, which typically achieves log 4 reductions in pathogens within just a few centimetres in high flux saturated flow conditions in porous sands. It therefore does not make sense to me that pathogens can travel tens let alone hundreds of metres through soils and I am skeptical of reports that claim that they do (the proper and accurate monitoring and sampling of groundwater is not simple). Obviously with very high permeability (fissured and fractured rock, coarse gravel) and very high flux (production boreholes) then longer distance contamination will be possible.

Users of wells and boreholes often contaminate the source through spillage and poor sanitary practice around the well head. Anyone worried about public health risk from contamination of groundwater should start by ensuring that well heads and springs are properly protected from surface contamination.

Meanwhile in the town where I live the greatest threat to environmental water quality stems from poorly maintained sewer systems. The pathogen count in our rivers below fully sewered catchments is orders of magnitude greater than the pathogen count in rivers below catchments which have only on-site sanitation. I would not be surprised if this were the case more often than not elsewhere in the world.

Hi all,

I notice your discussion about groundwater protection measures and the difficulty of implementing them, especially when this is about protection zones.

Traditionally, groundwater protection is based on precautionary principles and quite often, the protection zones which would be required based on the concepts which are mentioned for example in the SuSanA WG11 Factsheet, are not possible due to economic or social constraints.

Just to widen the perspective with a bit of stochastical modelling, i would like to make you aware of some very flexible groundwater protection guidelines which were recently introduced in New Zealand: "Guidelines for separation distances based on virus transport between on-site domestic wastewater systems and wells".

The Guidelines calculate separation distances for domestic on-site wastewater treatment systems based on virus movement and removal in the subsurface environment. The document provides a process and tables of calculated data, which, in conjunction with the specifics of a particular location, allow safe minimum separation distances (or the required log reduction in virus concentration) to be estimated.

You can directly access the report at:
www.google.de/url?sa=t&rct=j&q=&esrc=s&s...534169,d.Yms&cad=rja

But i also include it as an attachment to this message, probably i will open a new topic on the issue of gw-protection zones.

I am aware that the concept is more complex, but it offers a much more fact based approach and may help in situations where you need to make difficult choices and want to take probabilities into account.

Regards,
Leif

Thanks all - lots of really good information and links, hopefully I will have some time and good enough internet connection to have a look at those resources will I am still in Uganda.

When I get back I may follow up with a number of you because there is clearly some really interesting work that has been done in this area.

Has anyone come across any studies or projects that give an indication of how much catchment protection activities cost? e.g. tree planting costs per hectare, river bank restoration per km, soil-management training for farmers and so on? It may not be easy to make international comparisons but it could be useful for getting a feel for the order of magnitude of how much implementing protection costs.

Thank again!

Sean

Hi Sean and All,

BGR has done (or is still doing) on the issue of groundwater protection and sanitation. Here are listed some of their publications: www.bgr.bund.de/EN/Themen/Zusammenarbeit...sorgung_node_en.html

Best, Florian

Some more general briefing notes on groundwater management from the worldbank:
cap-net.org/sites/cap-net.org/files/wtr_..._tls/73_18_BNNo1.pdf
cap-net.org/sites/cap-net.org/files/wtr_...t_tls/37_GWMate6.pdf
cap-net.org/sites/cap-net.org/files/wtr_...tection_Strategy.pdf

and this one on groundwater quality protection:
cap-net.org/sites/cap-net.org/files/wtr_...Protection_Guide.pdf

Hope that helps.

Ok here are some usefull links I think:

Quite practical in regards to community managed catchment protection is this one from Helevetas Cameroon (maybe you know this one already since you mentioned them):
www.sswm.info/sites/default/files/refere...ction%20Handbook.pdf

Another good one, giving much infos on the theoretical background is this WELL study about pathogen transport in the ground:
www.lboro.ac.uk/well/resources/well-stud...ies-htm/task0163.htm
(Also have a look at their references, might give you a good starting point for further research)

A similar review to the above is this one, that might give some additional insights:
www.wrc.org.za/Knowledge%20Hub%20Documen...rSA_1995_02_0885.PDF

Edit: just stumbled on this: www.agw-net.org/ Maybe a usefull resource.

Dear Sean

I am Guneshwar Mahato from Nepal working in Rural Water Supply and Sanitation Project in Western Nepal. I have worked for 16 local level Water Use Master Plan preparation (political boundary level) in western and far-western development regions of Nepal.These plans basically prepared for the hilly regions of Nepal. Currently the project is supporting 9 districts to prepare more than 100 local level WASH plans (VDC and district WASH plans)in western region. More recently, a task force team (comprising of UNICEF, RWSSP-WN, RVWRMP, DoLIDAR, DWSS) has been formed to prepare a national guideline on "Community-led Water Safety Planning" which will consist of all types of rural water supply technologies like hand drilled tube wells, hand dug wells, private spring sources, rain water harvesting, gravity system, source conservation, deep bore holes, pumping systems (solar, electrical and wind powered) etc.
Regards
Guneshwar

Dear Mr. Sean,

In Pakistan, there is no control on the establishment a bare minimum distance of 30 metres between a toilet and a well. There are instances, where a toilet is close to a drinking water well. Even though, in some cases, a rural latrine may be connected to a septic tank, which in turn, is connected to a soak-pit, after initial period of operation during which the effluent is fairly treated; the effluent becomes problematic due to the overload of septic tank, the final effluent trickles out, percolates and moves horizontally along the ground contours to a well. There are many cases here of faecal contamination of well water.

I'm also on a look out, on how to deal with well water contamination from latrines.

F H Mughal
Karachi, Pakistan

Dear Sean

Thank you for your comments ,I like to send my article which presented as poster in Honnover,Germany 2008

In that presenation I expressed concern about rechargeable water resources.


with best regards;

Mohammad Mojtabaei
www.fpp.ir
Telfax:00985117629569
P.O Box:91865-358
Mashhad,Iran

Yeah, it's often stuff like that. In case of the spring catchment (for gravity fed piped water systems) areas in Nepal it was actually small scale lifestock herding that resulted in the most problems.
The catchments were close enough to the villages that the goats etc could be brought there by the children, yet sufficiently far away that they hadn't been utilized for agricultural production (one of the reasons why they were chosen as sources for the systems).
So the children were playing with the fences etc and the goats were happily eating up the vegetation and dumping their remains upstream of the spring.

No real solution was found to this problem either, except for further improving the spring protection structures to make them less vulnerable to problems of conterminated surface water entering (which helped only partially)... preventing the livestock use was really not an option for the villagers at all.
Upstream agricultural use of catchment was another problem, but since the sources had already been carefully selected, it was less common were I did the study.