Sources of Salinization of Groundwater in the Lower Yarmouk Gorge, East of the River Jordan

Round 1

Reviewer 1 Report

The paper entitled “Sources of salinization of groundwater in the Lower Yarmouk Gorge, East of the River Jordan” was submitted for review for possible publication. So here are my comments and suggestions:

1. Materials and Methods: the study fauked to establish what protocol for groundwater sampling was implemented, nor establish the stability of the methods used to obtain the groundwater from source.
2. Also, the sample was spiked with  1 ml Tm solution. There was no Discussion in the methodology as to correction of response for this treatment. 
3. There is disarray of presentations observed as evidence by the mention In page 18 of figure 3 which is found in page 8. This is too far from the discussion. It is a headache to turn back several pages to see what the authors mean.
4. The data presented does not justify the process being described. With so much data, all the authors did was to superficially relate one location to another without validation. Utilize you data efficiently by supporting your claims. Substantiate by counterchecking using existing mathematical or statistical models.
5. The conclusions failed to communicate with the study objectives, as such I wasnt able to see that the primary objective was achived.

Author Response

Note that the line numbers refer to first submitted version.

The paper entitled "Sources of salinization of groundwater in the Lower Yarmouk Gorge, East of the River Jordan" was submitted for review for possible publication. So here are my comments and suggestions:

1. Materials and Methods: the study fauked to establish what protocol for groundwater sampling was implemented, nor establish the stability of the methods used to obtain the groundwater from source.

The sampling procedure including nomination of instruments is now integrated into chapter 3.1.

2. Also, the sample was spiked with 1 ml Tm solution. There was no Discussion in the methodology as to correction of response for this treatment.

The Tm spike is used to check the recovery of REY in the preconcentration procedure. The recovery was always between 95-103 %.

3. There is disarray of presentations observed as evidence by the mention In page 18 of figure 3 which is found in page 8. This is too far from the discussion. It is a headache to turn back several pages to see what the authors mean.

Sorry for the headache but Fig. 1 is first cited in line 46. Does it makes sense to present the same Figure twice? Our answer is: no!

4. The data presented does not justify the process being described. With so much data, all the authors did was to superficially relate one location to another without validation. Utilize you data efficiently by supporting your claims. Substantiate by counter-checking using existing mathematical or statistical models.

Having studied the hydrology of the Yarmouk basin for about 10 years the hydrology of groundwater in the basin is known. In this contribution the salinization is the main topic. Knowing the geological development, only three sources of brines and possibly evaporites account for it. The aim was to evaluate the necessary quantities of them to explain the variety of salinities in groundwater.

Validation is given in Fig. 5 by presenting the correlation between various ions with Cl^-. The low-salinity end members are the assumed basaltic-rock- and limestone water according to the corresponding catchment lithologies and two different high salinity components. The results from Fig. 5 are substantiated by 3D visualization of the clustering of water samples along the first principle components (Fig. 7).

The chemical differences between the various sampled region are evident by eye screening Na⁺, Cl^-, Ca²⁺ and Mg²⁺ in Table 1. The code grouping of Table 1 is validated by code specific distributions in Figure 7.

5. The conclusions failed to communicate with the study objectives, as such I wasnt able to see that the primary objective was achived.

According to lines 37-38 the aims of this study were ”the identification of groundwater sources and their salinization in different geological formations in the well fields of the Lower Yarmouk Gorge”. In lines 322-336 and 337-346 the sources of groundwater and their sources of salinization are described, respectively.

Added to the manuscript:

South of LYF the artesian Mukeihbeh well field produces in its central segment groundwaters of almost pure basaltic-rock type with low contribution of limestone water and <0.3 vol-%) of Tertiary brine, hosted in deep Cretaceous and Jurassic formations. Further distal, the contribution of limestone water increases originating from the Ajloun Mts. North of the LYF, the Mezar wells, the springs of Hammat Gader and Ain Himma produce dominantly limestone water, which contains 0.14-3 vol-% of the Tertiary brine and hence possess variable salinity. The total dissolved equivalents of solutes gained by water/rock interaction and mixing with brine, TDE_WRI+brine, amounts to 10-70 % in the region comprising the Mukheibeh field, Ain Himma and Mezar 3 well, to 55-70 % in the springs of Hammat Gader, and to 80-90 % in wells Mezar 1 and 2. The type of salinization indicates that the Lower Yarmouk fault seemingly acts as the divide between the Ajloun and the Golan Heigths in the study area dominated groundwater. The Yarmouk River is the boundary between Israel and Syria on one side and Jordan on the other side and thus some transboundary flow occurs.

Reviewer 2 Report

The paper by Muller et al. titled: “Sources of salinization of groundwater in the Lower

Yarmouk Gorge, East of the River Jordan” provide a study about the identification of groundwater sources and salinization processes in different geological formations in the transboundary region of the Lower Yarmouk Gorge. The work is interesting and generally well written, only minor English checks are necessary. Here some suggestions for increase the overall quality of the work.

• Introduction: The introduction needs more explanation of the current literature and a discussion of how the work placed inside it. In particular as the author tried to identify all the possible mineralization processes in necessary to describe all possible methodologies and how they were employed in different part of the world. For example, read and maybe discuss some of this work:
• Busico, G., Cuoco, E., Kazakis, N., Colombani, N., Mastrocicco, M., Tedesco, D., Voudouris, K., 2018. Multivariate statistical analysis to characterize/discriminate between anthropogenic and geogenic trace elements occurrence in the Campania plain, Southern Italy. Environ. Pollut. 234, 260e269.
• Huang, P., Wang, X., 2017. Applying environmental isotope theory to groundwater recharge in the jiaozuo mining area, China. Geofluids. https://doi.org/10.1155/2017/9568349.
• Yang, Q., Li, Z., Ma, H., Wang, L., Martin, J.D., 2016. Identification of the hydrogeochemical processes and assessment of groundwater quality using classic integrated geochemical methods in the southeastern part of Ordos basin, China. Environ. Pollut. 218, 879e888. https://doi.org/10.1016/ j.envpol.2016.08.017.
• Machiwal D., Cloutier V., Güler C., Kazakis N. (2018) A Review of GIS-Integrated Statistical Techniques for Groundwater Quality Evaluation and Protection. Environmental Earth Science. 77:681.
• Kazakis N., Mattas C., Pavlou A., Patrikaki O., Voudouris K. (2017) Multivariate statistical analysis for the assessment of groundwater quality under different hydrogeological regimes. Environmental Earth Science. 76: 349.
• In Figure 1 replace the hill shade in background with a geologic/lithologic map of the area.
• Materials and Methods: add the overall accuracy of the analysis and the error associated to each analyte.
• Line 128: How do you define the background level of Cl in order to distinguish the two population?
• Paragraph 3.3. please explain all the passages in detail to make to procedure easy replicable.
• Line 181-194: the methodology applied for cluster the sample need to be better explained.
• Figure 7. It is possible to represent the cluster distribution upon the map.?

Author Response

Note that the line numbers refer to first submitted version.

The paper by Muller et al. titled: "Sources of salinization of groundwater in the Lower Yarmouk Gorge, East of the River Jordan" provide a study about the identification of groundwater sources and salinization processes in different geological formations in the transboundary region of the Lower Yarmouk Gorge. The work is interesting and generally well written, only minor English checks are necessary. Here some suggestions for increase the overall quality of the work.

Introduction: The introduction needs more explanation of the current literature and a discussion of how the work placed inside it. In particular as the author tried to identify all the possible mineralization processes in necessary to describe all possible methodologies and how they were employed in different part of the world. For example, read and maybe discuss some of this work:

- Busico, G., Cuoco, E., Kazakis, N., Colombani, N., Mastrocicco, M., Tedesco, D., Voudouris, K., 2018. Multivariate statistical analysis to characterize/discriminate between anthropogenic and geogenic race elements occurrence in the Campania plain, Southern Italy. Environ. Pollut. 234, 260e269.

- Huang, P., Wang, X., 2017. Applying environmental isotope theory to groundwater recharge in the jiaozuo mining area, China. Geofluids. https://doi.org/10.1155/2017/9568349.

- Yang, Q., Li, Z., Ma, H., Wang, L., Martin, J.D., 2016.  Identification of the hydrogeochemical processes and assessment of groundwater quality using classic integrated geochemical methods in the southeastern part of Ordos basin, China. Environ. Pollut. 218,879e888. https://doi.org/10.1016/j.envpol.2016.08.017.

- Machiwal D., Cloutier V., Güler C., Kazakis N. (2018) A Review of GIS-Integrated Statistical Techniques for Groundwater Quality Evaluation and Protection. Environmental Earth Science. 77:681.

- Kazakis N., Mattas C., Pavlou A., Patrikaki O., Voudouris K. (2017) Multivariate statistical analysis for the assessment of groundwater quality under different hydrogeological regimes. Environmental Earth Science. 76: 349.

The reviewer requests “to describe all possible methodologies and how they were employed in different part of the world”. This may be the subject of a textbook but not of our manuscript. In this contribution the salinization is the main topic. Knowing the geological development only three sources of brines and possibly evaporites account for it. The aim was to evaluate the necessary quantities of them to explain the variety of salinities in groundwater.

Validation is given by Fig. 5 by presenting the correlation between various ions with Cl^-. The low-salinity end members are the assumed basaltic-rock- and limestone water according to the corresponding catchment lithologies and two different high salinity components. These results from Fig. 5 are substantiated by 3D visualization of the clustering of water samples along the first principal coordinates (Fig. 7).

The chemical differences between the various sampled region are evident by eye screening Na⁺, Cl^-, Ca²⁺ and Mg²⁺ in Table 1. The code grouping of Table 1 is validated by code-specific distributions in Figure 7.

The selection of the best composition of basaltic-rock- and limestone water cannot be done by statistics. Here only the knowledge of the local hydrology and intuition can help. As stated in line 128, the best approaches for the basaltic-rock and limestone water are those with only the lowest Cl^-.

We nevertheless thank the anonymous reviewer for the suggested literature, which we partially referenced in the revised manuscript. We also clearly stated that the “expert knowledge” on the geochemistry of the region already identified the possible ongoing mixing processes and that the clustering method was applied to confirm this knowledge. Possible new insights gained through a full-fledged FA/PCA hence remain in our opinion outside the scope of this work.

In Figure 1 replace the hill shade in background with a geologic/lithologic map of the area.

Regarding the background of Fig. 1, there are geological maps of different parts of the area but not one for the entire area. These parts can hardly be combined. Creating a unified geological map for the entire area will require a lot of time and effort which are beyond the scope of our current paper.

Materials and Methods: add the overall accuracy of the analysis and the error associated to each analyte.

The relative standard deviation for each analyte is now given in Table 1.

Line 128: How do you define the background level of Cl in order to distinguish the two population?

As clearly stated in line 128: The lowest Cl^- concentrations published for the Golan Heights and Hauran Plateau Table A1. These values are the best approaches. In case they are still too high means that the contribution of other sources are higher than determined.

Paragraph 3.3. please explain all the passages in detail to make to procedure easy replicable.

Rephrased

Line 181-194: the methodology applied for cluster the sample need to be better explained.

We rewrote this paragraph with a much more detailed description of the applied methodology used for the clustering, with a discussion about our modelling choices and about the 3D visualization in Figure 7. We also added the references to algorithms and implementations used for this work.

Figure 7. It is possible to represent the cluster distribution upon the map.?

This question is difficult to understand because of its poor English. Probably the reviewer asks to show the clusters in Fig. 3. Therefore we additionally encircled the different well regions and give their full names.

Reviewer 3 Report

The manuscript deals with the detailed analysis of groundwater chemical composition in order to explain and shade light on the origin of waters and their salinity.
The paper is well written in clear and understandable manner; good and clear structure of particular section is applied. Analysis and interpretation of provided data is well done and described.

However I found some elements which needs to be improved. That is why I recommend the paper to major revision.

1. Line 38: “in the productive region of the Lower Yarmouk Gorge (LYG)..” – it is not clear what does mean productive region? Is it concerns the recharge area? Or discharge? Please rephrase this sentence, as well as in other places in the text if needed.
2. Line 47: „shortness of water” – please use the term “shortages of water” instead; make changes in all other places.
3. Figure 1: I suggest to replace the fig. 1 to section 2: Hydrogeological settings.
4. Line 115-116 - Since "The alkalinity was titrated to pH 4.3 with H₂SO₄ and given as HCO₃⁻" then why in tab. 1 values of alkalinity and HCO₃⁻ are different?
5. In Section 3 “Materials and methods” add analytical procedures for ph, Eh and EC – which equipment? The brand name (including electrode types) producer and country of origin must be specified. There are Eh values in Table 1 – are these vales concern the real calculated redox potential according to hydrogen electrode (in such case the values measured by the Eh-meter should be corrected by electrode constant in particular temperature ?
6. Line 136: use term “ Mg-Cl “ type water – instead of “Mg²⁺-Cl^- “ ; please apply this rule to other places in the whole text, and conclusions.
7. Lines 155-160: explain more about TDE – why it is suitable for use in investigation of the salinization origin? Please give some references here.
8. Line 173: use “Na/Cl “ ratio instead of “ Na⁺ / Cl^- ; it is well known fact that this is ionic ratio and applies to ions; the same other ratios – do not use ionic charges; indicate in which units the particular ratios are calculated; especially this is needed in plots , eg. Figure 6; apply this rule to other ratios and figures;  
9. Figure 4: please indicate which plot belong to (a) and each to (b) indicator.
10. Figure 5. When you give the correlation of various elements with Cl−, specify correlation factor R² (on other figures also add this). This figure is in the section which refers to correlation of elements.
    Caption to Figure 5: explain the abbreviations ES, As, etc.. or explain that this symbols refer to wells in Table 1.
11. Conclusions: Please conclude a few words about the fractions of waters in particular studied wells or group of wells /springs in the context of the water origin and formation.

Author Response

Note that the line numbers refer to first submitted version.

The manuscript deals with the detailed analysis of groundwater chemical composition in order to explain and shade light on the origin of waters and their salinity. The paper is well written in clear and understandable manner; good and clear structure of particular section is applied. Analysis and interpretation of provided data is well done and described.
However I found some elements which needs to be improved. That is why I recommend the paper to major revision.

1. Line 38: "in the productive region of the Lower Yarmouk Gorge LYG).." – it is not clear what does mean productive region? Is it concerns the recharge area? Or discharge? Please rephrase this sentence, as well as in other places in the text if needed.

Replaced by “well field region”

2. Line 47: „shortness of water" – please use the term "shortages of water" instead; make changes in all other places.

replaced

3. Figure 1: I suggest to replace the fig. 1 to section 2:  Hydrogeological settings.

Makes no sense because Fig. 1 is first mentioned in section 1, line 46.

4. Line 115-116 - Since "The alkalinity was titrated to pH 4.3 with H2SO4 and given as HCO3−" then why in tab. 1 values of alkalinity and HCO3− are different?

Thank you for indicating that error. There are no discrepancies between alkalinity and HCO₃^-.

5. In Section 3 "Materials and methods" add analytical procedures for ph, Eh and EC – which equipment? The brand name (including electrode types) producer and country of origin must be specified.

Now included in the text

There are Eh values in Table 1 – are these vales concern the real calculated redox potential according to hydrogen electrode (in such case the values measured by the Eh-meter should be corrected by electrode constant in particular temperature?

The name of the instrument and the respective probes, which have been used are integrated in the text.

6. Line 136: use term " Mg-Cl " type water – instead of "Mg2+-Cl- " ; please apply this rule to other places in the whole text, and conclusions.

Makes no sense because Mg-Cl means magnesium – chlorine, i.e. the elements, but here we need magnesium ion-chloride.

7. Lines 155-160: explain more about TDE – why it is suitable for use in investigation of the salinization origin? Please give some references here.

TDE is preferred by us because it is “independent on processes such as ion exchange with clay minerals, albitization and dolomitization”. In contrast TDS varies with these processes. TDE has proved as a tool in defining brine families in Israel (Möller et al. 2014, 14:291-309)

8. Line 173: use "Na/Cl " ratio instead of " Na+ / Cl- ; it is well known fact that this is ionic ratio and applies to ions; the same other ratios – do not use ionic charges; indicate in which units the particular ratios are calculated; especially this is needed in plots, eg. Figure 6; apply this rule to other ratios and figures;

Nothing is wrong with using the ionic charge (ref to comment to line 136. All ratios are estimated on equivalent basis. We stick to the correct chemical notation.

9. Figure 4: please indicate which plot belong to (a) and each to (b)indicator.

done

10. Figure 5. When you give the correlation of various elements with Cl−, specify correlation factor R2 (on other figures also add this). This figure is in the section which refers to correlation of elements. Caption to Figure 5: explain the abbreviations ES,As, etc. or explain that this symbols refer to wells in Table 1.

Added: The regression lines and R2 have been estimated by Microsoft Excel 2010.

11. Conclusions: Please conclude a few words about the fractions of waters in particular studied wells or group of wells /springs in the context of the water origin and formation.

Added:

South of LYF the artesian Mukeihbeh well field produces in its central segment groundwaters of almost pure basaltic-rock type with low contribution of limestone water and <0.3 vol-%) of Tertiary brine, hosted in deep Cretaceous and Jurassic formations. Further distal, the contribution of limestone water increases originating from the Ajloun Mts. North of the LYF, the Mezar wells, the springs of Hammat Gader and Ain Himma produce dominantly limestone water, which contains 0.14-3 vol-% of the Tertiary brine and hence possess variable salinity. The total dissolved equivalents of solutes gained by water/rock interaction and mixing with brine, TDE_WRI+brine, amounts to 10-70 % in the region comprising the Mukheibeh field, Ain Himma and Mezar 3 well, to 55-70 % in the springs of Hammat Gader, and to 80-90 % in wells Mezar 1 and 2. The type of salinization indicates that the Lower Yarmouk fault seemingly acts as the divide between the Ajloun and the Golan Heigths in the study area dominated groundwater. The Yarmouk River is the boundary between Israel and Syria on one side and Jordan on the other side and thus some transboundary flow occurs.

Reviewer 4 Report

I found the topic very interesting and innovative for introducing REE and Y as environmental tracers for groundwater flow characterization. Unfortunately, it needs some improvements related to the description of the adopted methodology. On the first, it is not clear at all the path the authors followed to set up the principal components to give the statistical elaboration and representation. I highlighted some sentences in the text which are definitely not clear. I think the authors have to work more on the soundness of their assumptions to explain the procedure they applied to arrive to the presented results.

Comments for author File: Comments.pdf

Author Response

Note that the line numbers refer to first submitted version.

I found the topic very interesting and innovative for introducing REE and Y as environmental tracers for groundwater flow characterization. Unfortunately, it needs some improvements related to the description of the adopted methodology.

Chapter 3.3 has been rephrased

On the first, it is not clear at all the path the authors followed to set up the principal components to give the statistical elaboration and representation.

We rewrote this paragraph with a much more detailed and precise description of the applied methodology used for the k-medoids clustering and with a discussion about our modelling choices and about the 3D visualization in Figure 7, and added the precise references to the employed algorithms and implementations. It’s not a PCA what we presented here, but a “principal coordinates analysis” (which is in practice equivalently done in a PCA as well), and it was used to maximize the readability and thus the interpretability of Figure 7. We are confident that the revised manuscript makes that completely clear.

Line 9: ..hence possess… is correct; TDE added after equivalents which explains TDE in line 10

Line 26: Y=yttrium

Line 148: ε_bw was explained in line 143

Lines 250-251: This sentence has been deleted.

I highlighted some sentences in the text which are definitely not clear.

We found only one sentence, which has been deleted.

I think the authors have to work more on the soundness of their assumptions to explain the procedure they applied to arrive to the presented results.

Having studied the hydrology of the Yarmouk basin for about 10 years, the groundwater the hydrology of the basin is known. In this contribution the salinization is the main topic. Knowing the geological development only three sources of brines and possibly evaporites account for it. The aim was to evaluate the necessary quantities of them to explain the variety of salinities in groundwater.

Validation is given by Fig 5 by presenting the correlation between various ions with Cl-. The low-salinity end members are the assumed basaltic-rock- and limestone water according to the corresponding catchment lithologies and two different high salinity components. The results from Fig. 5 are substantiated by 3D visualization of the clustering of water samples along the first principle components (Fig. 7).

The chemical differences between the various sampled regions are evident by eye screening of Na⁺, Cl^-, Ca²⁺ and Mg²⁺ in Table 1. The code grouping of Table 1 is validated by code-specific distributions in Figure 7.

The selection of the best composition of basaltic-rock- and limestone water cannot be done by statistics. Here only the intuition can help qand that is the decision to use only the lowest Cl- waters. That has been stated in lines 125-132.

In the Conclusion, we added:

South of LYF the artesian Mukeihbeh well field produces in its central segment groundwaters of almost pure basaltic-rock type with low contribution of limestone water and <0.3 vol-%) of Tertiary brine, hosted in deep Cretaceous and Jurassic formations. Further distal, the contribution of limestone water increases originating from the Ajloun Mts. North of the LYF, the Mezar wells, the springs of Hammat Gader and Ain Himma produce dominantly limestone water, which contains 0.14-3 vol-% of the Tertiary brine and hence possess variable salinity. The total dissolved equivalents of solutes gained by water/rock interaction and mixing with brine, TDE_WRI+brine, amounts to 10-70 % in the region comprising the Mukheibeh field, Ain Himma and Mezar 3 well, to 55-70 % in the springs of Hammat Gader, and to 80-90 % in wells Mezar 1 and 2. The type of salinization indicates that the Lower Yarmouk fault seemingly acts as the divide between the Ajloun and the Golan Heigths in the study area dominated groundwater. The Yarmouk River is the boundary between Israel and Syria on one side and Jordan on the other side and thus some transboundary flow occurs.

Round 2

Reviewer 1 Report

With the most recent revision submitted, these are my comments:

1. On the previous comments: There is disarray of presentations observed as evidence by the mention In page 18 of figure 3 which is found in page 8. This is too far from the discussion. It is a headache to turn back several pages to see what the authors mean.

Your response is:  Sorry for the headache but Fig. 1 is first cited in line 46. Does it makes sense to present the same Figure twice? Our answer is: no!

My point is: This is just one of the many instances that this practice was observed in the manuscript. This is the main reason why the paper is disarray and confusing.  As such, the authors are advised to organize ideas and thoughts as they present the findings and discuss it.  I perfectly know that it doesn't make sense to present the figure twice and it was neither my suggestion all.  

2. On the comment: The data presented does not justify the process being described. With so much data, all the authors did was to superficially relate one location to another without validation. Utilize you data efficiently by supporting your claims. Substantiate by counter-checking using existing mathematical or statistical models.

Your 1st paragraph response was: Having studied the hydrology of the Yarmouk basin for about 10 years the hydrology of groundwater in the basin is known. In this contribution the salinization is the main topic. Knowing the geological development, only three sources of brines and possibly evaporites account for it. The aim was to evaluate the necessary quantities of them to explain the variety of salinities in groundwater.

My point is: Having studied the hydrology of the basin for 10 years does not justify and answer the issue.  You should have known better how you will generate valid conclusions on each findings and not the conclusion of other authors.  Further, the readers will never know your extensive works unless you presented valid conjectures, arguments about the novelty of you paper.  There is no body asking how many years you have worked on this, what I am asking is do your 

On your 2nd Paragraph response:  Validation is given in Fig. 5 by presenting the correlation between various ions with Cl^-. The low-salinity end members are the assumed basaltic-rock- and limestone water according to the corresponding catchment lithologies and two different high salinity components. The results from Fig. 5 are substantiated by 3D visualization of the clustering of water samples along the first principle components (Fig. 7).

My point: You are taking each suggestion in a very literal manner. The point again here is fixing the whole structure. 

On your 3rd paragraph response:  The chemical differences between the various sampled region are evident by eye screening Na⁺, Cl^-, Ca²⁺ and Mg²⁺ in Table 1. The code grouping of Table 1 is validated by code specific distributions in Figure 7.

My point: doe your 10-year extensive research validated only by "eye screening?" do better than this. You are aiming for international publication.  

3.  The conclusion was now tailor made to fit the objectives, Now fix the paper structure as mentioned.

Author Response

1) My point is: This is just one of the many instances that this practice
  was observed in the manuscript. This is the main reason why the paper
  is disarray and confusing. As such, the authors are advised to
  organize ideas and thoughts as they present the findings and discuss
  it. I perfectly know that it doesn't make sense to present the figure
  twice and it was neither my suggestion all.

Reply: We revised the manuscript reorganizing the order of many of our arguments and rewriting introduction and conclusion. We are confident that the new paper structure has greatly improved its readability and the logical succession of hypotheses and evidence-based results.

2)  My point is: Having studied the hydrology of the basin for 10 years
  does not justify and answer the issue. You should have known better
  how you will generate valid conclusions on each findings and not the
  conclusion of other authors. Further, the readers will never know your
  extensive works unless you presented valid conjectures, arguments
  about the novelty of you paper. There is no body asking how many years
  you have worked on this, what I am asking is do your

Reply: We believe that with this new revision we made our argumentative line of thoughts much more logical and understandable. We now state clearly our aims and working hypotheses in the introduction; some sections have been shifted around to follow a more logical structure and we completely rewrote the conclusion.

3)  My point: You are taking each suggestion in a very literal manner. The
  point again here is fixing the whole structure.

Reply: It has been for us difficult to interprete the wishes of the reviewer since his comments are, to us, cryptic with respect to what should be changed. Nevertheless, we reworked our manuscript in order to ease the understanding and clarify our line of toughts.

4)  My point: doe your 10-year extensive research validated only by "eye
  screening?" do better than this. You are aiming for international
  publication.

Reply: We are confident that the presented results, achieved through “classical” geochemical interpretation (subsections 4.1-4.3) are sound. The statistical clustering – performed on a subset of the available hydrogeochemical data – validate our reasonament. We believe that the whole line of arguments is much clearer in this new revision.

5) The conclusion was now tailor made to fit the objectives, Now fix
   the paper structure as mentioned.

Reply: We completely rewrote the conclusion.

Reviewer 2 Report

I have read the revised manuscript which has covered my initial comments and hence i have no further reccomentations.

Author Response

•   I have read the revised manuscript which has covered my initial
    comments and hence i have no further reccomentations.

Reply: thank you for the suggestions which helped us improve the manuscript

Reviewer 3 Report

I am satisfied with the authors improvements and do not have more remarks. 

I recommend the paper to publication.

Author Response

• I am satisfied with the authors improvements and do not have more   remarks. I recommend the paper to publication.
  
  
  

Thank you for the suggestions which helped us improving the manuscript.

Reviewer 4 Report

The new version of this paper is definitely better than the previous one. It needs only some improvements referred to Figure 5, 7 and 8 which are not clear enough. On the other side, the paper needs to be read carefully by the authors to eliminate some English language errors.

Author Response

 1) The new version of this paper is definitely better than the previous
  one. It needs only some improvements referred to Figure 5, 7 and 8
  which are not clear enough. On the other side, the paper needs to be
  read carefully by the authors to eliminate some English language
  errors.

Reply: English language has been checked again, large portions of the manuscript have been rewritten and the pictures (with now a somewhat different ordering) have also been improved.