Dear Ian,

I have read the DWAF publications you have put into the library with great interest. Are there also standards for South Africa regarding e.g. the quality of wastewater treatment plant effluents that are discharged into the environment (usually into surface waters)?

Thanks,
Andrea

Thank you, Andrea, for the way you included the remarks and the excellent updates.
Kind regards,
Jan

Dear all,

I'm currently reviewing the suggested changes in the factsheet and would like to hear your suggestions on this paragraph:

In many European countries source protection concepts have been based on a rule that most pathogens are reduced by 99% within 50 days of transit time in the aquifer. Where drinking water wells are located close to a pollution source (e.g. cesspits without any further treatment), travel times of the groundwater will be much shorter than 50 days. Therefore, water users face increased health risks. It should be noted here that the “99% reduction in 50 days” rule of thumb should not be taken too seriously. Important variations exist (Table 1).

I have added the first sentence as it wasn't clear to everyone where this 50 days rule came from. Declan has commented that in Australia they use another method. Could I ask you Declan or Leif to add a sentence in this paragraph on your alternative?

I also left 3 other comments by Declan in the document for discussion. Please feel free to change the text (in the mode "track changes") or discuss in the forum on the issues raised. Bear in mind that the deadline for changes should be Friday 3rd (end of this week).

Thanks, Declan, for the valuable comments and text corrections, I've posted the new version of the factsheet below.

Best regards,
Andrea

I recieved this e-mail from Leif Wolf at CSIRO in Australia and am posting it with his permission here (posted by Elisabeth von Muench):
++++++

Dear Andrea and Elisabeth,
I am not sure if the fact sheet is already in print. In the course of the quality assurance for CSIRO, the fact sheet was subject to an internal review, to allow my participation as an author. I find the comments from my colleague Declan Page helpful, maybe you can still incorporate some of them in this edition, or otherwise consider them for the next update of the fact sheet.

All the best,
Leif

---

Dr Leif Wolf
Research Team Leader
CSIRO Land & Water

See Word document with comments by Declan Page:



Leif told me about Declan Page:
Dr Declan Page is a specialist on managed aquifer recharge in Australia, you see his profile at:
www.csiro.au/Organisation-Structure/Divi...ater/DeclanPage.aspx
He is working a research team leader with Peter Dillon, who is leading the IAH Commission on Managed Aquifer Recharge.
He is an expert on subsurface pathogen transport (see attachment) and quantitative microbial risk assessment.

++++++++++

Note about the process: We have been collecting feedback on the factsheet compilation until 5 Feb. and will then proceed with preparing the printed version.
You can see the factsheet compilation, as well as the individual 13 factsheets, here:
www.susana.org/lang-en/library/rm-susana-publications

Thanks Ian for the files and the reactions on those comments. You mention that you did studies on the VIP in very sandy soils - travel times of microorganisms. Is there a publication we could cite in the factsheet? So far I left the sentence as it was ("can travel less that a kilometer"), because if we start naming examples from different soils I am sure we end up at even less that 5 m (e.g. clay). But nevertheless I'd be happy to read this study, possibly it can even be uploaded in the Susana library?

Have a peaceful christmas everyone,
Andrea

Dear Elisabeth,
apologies for the late response to your queries from my side - I am still learning how this forum works.

In response to your queries that I may have initiated:

travel of contaminated groundwater = only 5m - tests were undertaken in South Africa where VIP latrines were installed in sandy soil - an area of very fine sand. Test pits were dug next to the pit and samples of the shallow groundwater taken and analysed. It was found that there were no coliform bacteria at a distance of 5m from the base of the pit. Of course there were higher nitrate levels, but the fine sand had effectively filtered out the bacteria and larger microorganisms. We are well aware though that in conditions of fractured rock travel of microorganisms can be extensive.

Ecological sanitation as I understand it (I may be mistaken) is a sanitation system that has minimal impact of the environment - particularly the groundwater. This would include all desiccating toilets, most composting toilets, and generally the urine diversion types. We dont use the term "ecosan" because a commercial company named their desiccating toilet an ecosan toilet, so we have opted to spell it out in full (i.e. in South Africa)

The "Groundwater Protocol" is a procedure used in South Africa. It should be on the South African Department of Water Affairs' website www.dwa.gov.za, but it seems not to have been uploaded. I will try to attach it to this mail and if it is useful to others, please put it in the library. Please note that the tables (the second file attached) must be attached at the end of the main document (the first file attached).

I think that is all I can comment on

Best regards

Ian Pearson

Dear all,

In my role as editor for the whole factsheet compilation, I recently read the factsheet of WG 11 on groundwater - as an outsider and lay person. Which I think is a good test for the factsheet.
I think it reads very well and gives a good overview of the main issues - thank you for putting in the work to write and update it!

And especially thanks to those people who have put their comments here on the forum for all to see (Dexter Lo, Jan Taat, Ian Pearson, Rabani Adamou, Michael Klaus, Leif Wolf and of course Andrea Nick).

I just have some small queries back to the authors and contributors:

In some instances, contaminated groundwater travels a distance of less than a kilometer; however, in many cases of single source contaminations have spread beyond ten kilometres from the source, depending on the type of contaminant and the hydrogeological conditions.

--> one of the reviewers said it can even be as little as 5 m (instead of 1 km), is that true?

The significant dose varies widely comparing different pathogens (bacteria, viruses, worm eggs, etc) occurring in human excreta, especially in the tropics.

--> I think we should mention that worm eggs are not usually an issue in terms of groundwater pollution as they get filtered out by the soil before reaching the groundwater, right?

The main health risk associated with contaminated groundwater, i.e. diarrheal disease, opportunistic viral infections and other resulting diseases, causes up to 3 million deaths annually.

--> This number is new to me. I only know the 2.5 million children under 5 who die. Is it really 3 million only from contaminated groundwater? If yes, then you should cite a reference? (one of the reviewers also noted this)

For instance, safe setback distances may vary from several tens of meters in areas with thick clay cover to safe setback distances of more than 5 km in karstic aquifer systems.

--> I can roughly imagine what a "safe setback distance" is but what is the exact definition of this term?

The section on "Chemical pollution" is divided into nitrogen and phosphorus. Then a new section starts on "organic micropollutants".
Wouldn't it be more logical if it was arranged like this:

2. Pollution by chemicals
2.1. Pollution due to nitrogen compounds
2.2. Pollution due to phosphorus compounds
2.3. Pollution due to organic pollutants (correct term? E.g. chlorinated hydrocarbons, BTEX)
2.4. Pollution due to organic micropollutants (or better "emerging contaminants"?) e.g. pharmaceutical residues

Is the arsenic pollution part, which falls within the phosphorus section, still linked to phosphorus pollution, or is it a new topic? I mean this part here:

In some settings, due to the infiltration of waste water, toxic compounds like arsenic are released. For instance, below the city of Hat Yai in Thailand, the increase of arsenic due to the reductive dissolution of iron oxides is well described (Lawrence et al., 2000).

About this paragraph:

Tens of thousands of chemicals enter sewer systems or on-site sanitation systems and eventually wastewater treatment plants (WWTP), and/or groundwater and because these contaminants are usually quite small (molecular weight predominantly varies between 50 and 1000 Da), regular municipal WWTPs or on-site sanitation systems do not remove these polar persistent organic pollutants.

--> I think molecule size is not the decisive factor whether a molecule is broken down or not (ammonia-N is also small, but is nitrified easily (?))

About this sentence:

Where households are located within this zone, their sanitation system should be either an ecological sanitation solution or a system where the wastes are removed from site.

--> what exactly is meant by an ecosan solution? = one that does not pollute groundwater? (this one was added by Ian Pearson if I remember right)

About this paragraph:

Elsewhere there have been other methodologies developed for the same purpose, such as South Africa’s “Ground Water Protocol” which is a procedure that all development and local government agencies are required to follow when planning a new sanitation project. The approach is risk based, taking into account the contaminant load, the vulnerability of the aquifer, and the strategic value of the aquifer.

--> Ian, do you have a website or reference which could be included? Sounds interesting.

About this paragraph:

From the groundwater resource protection point of view, the catchment needs to provide a recharge area which is part of the ecosystem mosaic, free of human activities. The area in which humans consume water for domestic and industrial use should be situated downstream of the recharge area while agricultural activities may lie even further downstream, allowing for use of nutrients from domestic water (and sanitation).

--> the second sentence sounds to me a bit linear and idealistic. There is always someone else downstream so how can this really work in practice? Basically, people should not live so close together along the same stream...

About this closing sentence:

Therefore sanitation and groundwater issues including capacity development have to be addressed on the highest political level.

--> what does "highest political level" mean and isn't it more important to address this at all levels of government, i.e. not just the highest but also e.g. at the local government level?

And finally, regarding photos: It is difficult to find good groundwater photos, as groundwater is "invisible". There are only photos of either groundwater pollution or maybe of someone pumping groundwater. Does anyone have good "groundwater photos" (or schematics) which they may like to add to our photo collection on flickr? So far, we have received these, see our groundwater set here:
www.flickr.com/photos/gtzecosan/sets/72157628473846447/

If you have photos to add, just e-mail them to me (if too large then send them in a zip file via www.sendspace.com)

My favourite photo so far (which I would suggest to put on page 1 of the factsheet) is this one from Lusaka (taken by Kennedy Mayumbelo whom I met during his MSc time at UNESCO-IHE in Delft):

Pit latrine and well in close proximity by Sustainable sanitation , on Flickr

And I attach the current Word document for your information (but please don't dive into editing it, as we from the secretariat are right now busy with it too - and the deadline is basically over now, apart from minor changes).

Regards,
Elisabeth

Dear members and those interested in working group 11,

thanks a lot to everyone who contributed to our factsheet and to this discussion in the last weeks. I am especially happy to read new names and very dedicated statements as well as thorough reviews of the factsheet.
Dear Michael and Ian, I hope you are already members of the working group, so that you are also added to our e-mail-list and we can make sure you are included in the
discussions to come. (You become a member by ticking the box that your are interested in the groundwater topic.)

The working group leads have now consolidated the changes done in the document and I would ask other keen contributors to wait for our next working group "project" to give your contributions to (which is already in preparation).
Feedback on the updated factsheet was now also asked from the original authors of the factsheet who stand with their names for the content given. The names of those who
contributed to the update will appear as "Contributors" (please provide your full names, institutions and e-mail-addresses either here or by e-mail to me).
Please understand that general comments cannot be taken up. There will be room in publications to come to accomodate these discussions. We want to keep the factsheet short and crisp, and as Leif put it, it is already a very useful document. We should rather put our energies into something new, then to rewrite papers which have been discussed among a different group at that time. Your comments will not be brushed aside, but we should channel them into publications that provide the room to elaborate them.

I'd like to encourage you to give a short introduction to yourself and your professional background as well as to the topics that you are interested in and/or working on. This forum is a very good way of getting in contact with people who
might work in the same area or do research in similar topics, etc. Dexter and Jan have given a very good example for an introduction, thanks to you guys!

Looking forward to some enlightening discussions,

Andrea
co-lead of WG 11
This email address is being protected from spambots. You need JavaScript enabled to view it.


Andrea Nick is a hydrologist who is currently working for the Federal Institute for Geosciences and Natural Resources (BGR) in a development cooperation project in Zambia (Groundwater Resources Management Support Project - see www.bgr.bund.de/zambia). Her focus is on groundwater quality and groundwater protection, including vulnerability assessment. Her special interests are in faecal groundwater pollution in urban areas, groundwater-friendly re-use oriented sanitation systems, and groundwater advocacy.

Some direct comments on the earlier posts:
@ Michael: Vulnerability is a key issue for groundwater protection and is therefore in my view definitely right to be discussed in this working group.

@ Ian: thank you for your valuable comments on filtering. What we tried to get across with this Factsheet is that groundwater as a resource needs protection from pollution, and that if it is protected from e.g. faecal bacteria in the first place, filtering as a form of treatment might become unneccessary. Thus, the factsheet focuses on protection rather than treatment, and highlights natural processes.

Dear Dexter Lo & Jan Taat and other members,

I have made a few suggestions to the text as attached.

I was just concerned about one issue in particular, and that is the assumption that microorganisms will be transported freely in the seepage water and the only factor affecting their numbers is natural die-off. It is well known that a sand filter significantly reduces micro-organisms at a far higher rate than natural die-off, and in fact slow sand filters work on this principle. I would suggest that we reduce the emphasis and tables regarding natural die-off rates, and rather give some data on the impact of filtration on organism numbers.

Regards - Ian

Dear all,

I would like to mention an aspect which is usually not considered in literature on "Water and Sanitation" and also not in the daily practice. Might be it could be a topic of the Factsheet under Source Protection.

Crucial for the extraction of safe drinking water is an appropriate location of the water extraction point. That applies especially to places where sanitation facilities are weak. One major criteria for selecting a drilling point for a well should be the local relation to the possible sources of emissions under consideration of the groundwater flow. Wells on unsuitable sites with critical catchment areas can hardly be protected properly.

An important issue regarding the selected location of a well is the vulnerability of the aquifer due to the permeability of the unsaturated zones and the consequences regarding the repuirements for the well design, but perhaps that‘s a topic for another Working Group.

One more suggestion: In the draft the difference between groundwater resource and source of groundwater for water uses is not really explained. When we think about “managing” water and land use we should make the difference clear. We protect the Resource for “current and future uses” in a wide scope and we protect a currently used Water Source in a limited area with specific and often very limiting measures regarding land use.

Kind regards

Michael Klaus
Adviser National Environmental Protection Agency
Kabul, Afghanistan

Dear Colleagues

Please find attached the document with my observations.

- Dear Wolf, I think that the micropollutants were not too much stressed in this document. Remind that they are widespread and very harmfull!!!
But what's sure is that the chemical pollution part must be rewritten to clearely indicate sources and impacts of polluted waste water and natural micropollutants on groundwater.

- Doreen, Emerging micropollutants are also chemicals and will enter in chemical pollution. If the real objective here is to lay emphasis on Emerging pollutants contribution, it must be treated as chemical pollution subtitle. Otherwise as Dr Wolf corrected it, Organic micropollutants are not all emerging pollutants; they constitute a new class of organic micropollutants.

Sincerely,
Dr Rabani Adamou
Responsable du Laboratoire de Photochimie Analytique & Ecotoxicologie
FAST, UAM, Niamey/Niger

Dear All,

Leif Wolf sent the e-mail below concerning the Factsheet for Working Group 2. I am now posting it here with his permission. I look forward to your feedback!

++++++

Dear colleagues,

Please find attached some minor comments to a useful document.

I think we should not stress the micropollutants too much in this context, since their impact on human health is currently very low.

Kind regards,
Leif Wolf

Research Team Leader
CSIRO Land & Water