Comprehensive Study on Hydrogeological Conditions and Suitability Evaluation of In Situ Leaching for Sandstone-Hosted Uranium Deposit in Erlian Basin
, Wanjun Jiang 1,2,3,*, Yizhi Sheng 4, Wei Wang 1,2,3 and Chao Tang 1,2,3
Round 1
Reviewer 1 Report (New Reviewer)
Comments and Suggestions for AuthorsIn principle, this is a good Case Report, so I recommend a publication after a major revision. I will just skip the summary part and leave a few specific comments to help you level up your quality and professional rigour. A minor check (revision) will be expected once the first round of deep and extensive revision is accomplished. The following comments can be respected and rebutted in a kind manner.
1. Line 1: Please specify your article type. Type of the paper (Article)? In terms of academic novelty, this contribution still lacks scientific advancement and new insights from theoretical and practical perspectives. However, this work deserves to be recognized as an utterly comprehensive case study in this field, which was just mentioned in the title. According to the article types in the MDPI submission platform, the correct option for your case should be “Case Report”. A good example can be found from the link: https://doi.org/10.3390/geosciences13050146.
2. Line 10: Please do not highlight the equality of contribution to this manuscript here. Instead, it would be best if you relocated the authors’ credits in the Author Contributions in Lines 593-597.
3. Line 18: Please do not use abbreviations here because readers cannot quickly track all notations for them for their first scanning of your abstract.
4. Line 19: A single space should be left between the value and unit. Also, you have a few punctuation issues, e.g., 0.25 ~ 5.64m/d respectively ->0.25 ~ 5.64 m/d, respectively. Please filter out your punctuation issues with assistance from grammar software, such as Grammarly and Writefull. Please tackle all those having similar problems in the rest of the content.
5. Line 20: There is no better or worse permeability, in fact. The permeability [L2] can be either higher or lower (high/low permeable in adjective), corresponding to higher or lower hydraulic conductivity [L/T]. Please scrutinize all terminology you used from seepage mechanics with a professional English proofing editor. Please tackle all those having similar problems in the rest of the content.
6. Line 24: the study area would be classified into three grades. I’d rather call it a self-defined classification rather than define anything for these three grades. English writing could be tremendously improved in this regard.
7. Line 34: The citation format you inserted here accords with the ACS style instead of the MDPI style. Both are almost presented the same, while the font size of MDPI should be equal to the main text instead of the superscripted version. Besides, please do not forget to leave a single space between the end of a sentence and the citation insertion.
8. Lines 68-78: The research gap identification presented here is sufficient for a Case Report. However, you forgot to highlight this so-defined gap in your abstract in Line 13. Please write up a short version of this as in the second sentence of your abstract. It will undoubtedly dazzle a few readers in this field.
9. Line 79: You mentioned marine areas here, whereas, in the latter content, you described the Erlian Basin in Mongolia. Have you additionally analyzed hydrogeological conditions in near-shore marine areas? If not, please correct or delete it in Lines 79, 198, and 460.
10. Line 101: (Figure XX) -> (see Figure XX). Please tackle all those having similar problems in the rest of the content.
11. Figure 2: Any depths herein?
12. Equations (1)-(3): Please put all math symbols into italics, e.g., Equation (3) T = KM. What is the definition of k in small letters in Equation (2), e.g., hydraulic conductivity (coefficient of permeability) or intrinsic permeability (just permeability)? Please specify. Also, what is the suction hole filter in Line 194? Any English jargon for this?
13. Table 1: K, Q, h, and H in italics, please!
14. In Chapter 3, Materials and Methods, the following work, https://doi.org/10.3390/geosciences13050146, could be reviewed and cited in relevant content in the latter hydrogeological field testing session.
15. Lines 97 and 268: What is the definition of NE? Any consideration of an abbreviation list in alphabetic order after conclusions? Or, it should be given for its first appearance in the main text.
16. Line 265: aquifers are poorly developed with low water content? -> with limited groundwater storage, right? Usually, water content is used to describe soil moisture in the vadose zone (unsaturated soil) above the groundwater table (phreatic surface) in an unconfined aquifer, right?
17. Figures 4, 5, and 6: The overall quality of Figures 4, 5, and 6 is acceptable, but a few legends were shown in many minor-sized letters that can hardly be read. You may also want to assign subplotting codes, such as Figure 4(a) and 4(b), to the top and bottom subplots.
18. Line 330: Consistency of Figure or Fig. throughout your manuscript, please. MDPI requires Figure than Fig. Please tackle all those having similar problems in the rest of the content, e.g., Lines 364, 387, 529, etc.
19. Line 374: Good permeability (good or bad, or high or low)?
20. Line 446: Chinglsh expression, e.g., groundwater permeability? Can groundwater have a permeability? What are the definitions of intrinsic permeability and coefficient of permeability (i.e., hydraulic conductivity)? In fact, in hydrogeology, hydraulic conductivity is often adopted, while coefficient of permeability is usually applied in Geotechnical Engineering.
21. Line 477: deteriorating permeability? -> decreasing/reducing permeability, right? There is no good or bad, flourishing or deteriorating for permeability.
22. Table 5: The classification herein looks really messy for each category.
23. Table 6: Please replace your Chinese word with or, e.g., <10 or >100, in the last column in Table 6.
24. Overall, this paper was written in a form that seems a little bit wordy. If possible and applicable, the authors should consider refining and polishing this manuscript by shortening the lengthy expressions and redundancy. By doing so, the presenting quality of this work will be massively enhanced.
Comments on the Quality of English LanguageModerate editing
Author Response
Dear Reviewer,
We sincerely appreciate your constructive comments. We have revised the manuscript accordingly and responded to your comments point-by-point as listed below. To facilitate reviewer and editing viewing, we have used normal blue font for our response and highlighted text for changes made to the revised manuscript. We hope the revised manuscript is found suitable for publication in Water.
On behalf of all the authors,
Dr. Wanjun Jiang
Tianjin Center, China Geological Survey
COMMENTS TO THE AUTHOR:
Reviewer 1
- Line 1: Please specify your article type. Type of the paper (Article)? In terms of academic novelty, this contribution still lacks scientific advancement and new insights from theoretical and practical perspectives. However, this work deserves to be recognized as an utterly comprehensive case study in this field, which was just mentioned in the title. According to the article types in the MDPI submission platform, the correct option for your case should be “Case Report”. A good example can be found from the link: https://doi.org/10.3390/geosciences13050146.
Response: Thank you for your comments. We have diligently studied and cited the article "Measurement of In-Situ Flow Rate in Borehole by Heat Pulse Flowmeter: Field-Case Study and Reflection," which you recommended, and have modified its classification to a Case Report.
- Line 10: Please do not highlight the equality of contribution to this manuscript here. Instead, it would be best if you relocated the authors’ credits in the Author Contributions in Lines 593-597.
Response: As suggested, we have relocated the authors’ credits in the Author Contributions in Lines 593-597.
- Line 18: Please do not use abbreviations here because readers cannot quickly track all notations for them for their first scanning of your abstract.
Response: As suggested, we have added the description of Q and K in Lines 18.
- Line 19: A single space should be left between the value and unit. Also, you have a few punctuation issues, e.g., 0.25 ~ 5.64m/d respectively ->0.25 ~ 5.64 m/d, respectively. Please filter out your punctuation issues with assistance from grammar software, such as Grammarly and Writefull. Please tackle all those having similar problems in the rest of the content.
Response: As suggested, in the revised manuscript, we have added a single space between the value and unit. Additionally, we have carried out a thorough grammatical check of the entire text and corrected similar errors.
- Line 20: There is no better or worse permeability, in fact. The permeability [L2] can be either higher or lower (high/low permeable in adjective), corresponding to higher or lower hydraulic conductivity [L/T]. Please scrutinize all terminology you used from seepage mechanics with a professional English proofing editor. Please tackle all those having similar problems in the rest of the content.
Response: Thank you for your comments, we have replaced “better or worse” with “higher or lower” in Lines 20, 372, 573.
- Line 24: the study area would be classified into three grades. I’d rather call it a self-defined classification rather than define anything for these three grades. English writing could be tremendously improved in this regard.
Response: Thank you for your comments, in this study, we primarily adhere to the Chinese National Standard for Hydrogeological Exploration of In situ Leaching Sandstone Type Uranium Deposits (EJ/T 1194-2005) to systematically classify in-situ leaching sandstone-type uranium deposits.
- Line 34: The citation format you inserted here accords with the ACS style instead of the MDPI style. Both are almost presented the same, while the font size of MDPI should be equal to the main text instead of the superscripted version. Besides, please do not forget to leave a single space between the end of a sentence and the citation insertion.
Response: Thank you for your comments, we have modified the citation format.
- Lines 68-78: The research gap identification presented here is sufficient for a Case Report. However, you forgot to highlight this so-defined gap in your abstract in Line 13. Please write up a short version of this as in the second sentence of your abstract. It will undoubtedly dazzle a few readers in this field.
Response: As suggested, in the revised manuscript, we have added a short version of the research gap in the second sentence of abstract.
- Line 79: You mentioned marine areas here, whereas, in the latter content, you described the Erlian Basin in Mongolia. Have you additionally analyzed hydrogeological conditions in near-shore marine areas? If not, please correct or delete it in Lines 79, 198, and 460.
Response: Thank you for your comments, we have corrected them in Lines 77, 196, and 455.
- Line 101: (Figure XX) -> (see Figure XX). Please tackle all those having similar problems in the rest of the content.
Response: As suggested, we have replaced “(Figure XX)” with “(see Figure XX)” in Lines 99, 153, 155, 242, 312, 326, 360, 383, 416.
- Figure 2: Any depths herein?
Response: As suggested, we have added the depths in Figure 2.
- Equations (1)-(3): Please put all math symbols into italics, e.g., Equation (3) T = KM. What is the definition of k in small letters in Equation (2), e.g., hydraulic conductivity (coefficient of permeability) or intrinsic permeability (just permeability)? Please specify. Also, what is the suction hole filter in Line 194? Any English jargon for this?
Response: Thank you for your comments, we have put all math symbols into italics. In the Equations (1)-(3), K represents the hydraulic conductivity (coefficient of permeability). K is obtained through iterative calculations using equations 1 and 2.
- Table 1: K, Q, h, and H in italics, please!
Response: As suggested, we have changed the font of K, Q, h, and H to italics in Table 1.
- In Chapter 3, Materials and Methods, the following work, https://doi.org/10.3390/geosciences13050146, could be reviewed and cited in relevant content in the latter hydrogeological field testing session.
Response: Thank you for your comments, this article has been reviewed and cited. (Lines 667, 668)
- Lines 97 and 268: What is the definition of NE? Any consideration of an abbreviation list in alphabetic order after conclusions? Or, it should be given for its first appearance in the main text.
Response: Thank you for your comments, we have added the definition of NE. Furthermore, we conducted a thorough review of the entire manuscript to confirm that all abbreviations are fully spelled out upon their initial occurrence in the main text.
- Line 265: aquifers are poorly developed with low? -> with limited groundwater storage, right? Usually, water content is used to describe soil moisture in the vadose zone (unsaturated soil) above the groundwater table (phreatic surface) in an unconfined aquifer, right?
Response: As suggested, we changed " water content " to " groundwater storage " in Lines 260-263.
- Figures 4, 5, and 6: The overall quality of Figures 4, 5, and 6 is acceptable, but a few legends were shown in many minor-sized letters that can hardly be read. You may also want to assign subplotting codes, such as Figure 4(a) and 4(b), to the top and bottom subplots.
Response: As suggested, we have adjusted the text in the legend to the appropriate size. (Figures 4, 5, 6)
- Line 330: Consistency of Figure or Fig. throughout your manuscript, please. MDPI requires Figure than Fig. Please tackle all those having similar problems in the rest of the content, e.g., Lines 364, 387, 529, etc.
Response: Thank you for your comments, we have tackled all those having similar problems in the rest of the content.
- Line 374: Good permeability (good or bad, or high or low)?
Response: Thank you for your comments, combining Suggestion 5, we have already made modifications to similar problems.
- Line 446: Chinglish expression, e.g., groundwater permeability? Can groundwater have a permeability? What are the definitions of intrinsic permeability and coefficient of permeability (i.e., hydraulic conductivity)? In fact, in hydrogeology, hydraulic conductivity is often adopted, while coefficient of permeability is usually applied in Geotechnical Engineering.
Response: Thank you for your comments, we have revised the previous expression in Lines 441, 444. Additionally, we have replaced the coefficient of permeability with hydraulic conductivity.
- Line 477: deteriorating permeability? -> decreasing/reducing permeability, right? There is no good or bad, flourishing or deteriorating for permeability.
Response: As suggested, we have modified in Line 477.
- Table 5: The classification herein looks really messy for each category.
Response: As suggested, we divided the categories more clearly. The previous classification was based on the raw data from the pumping test results, and now we have further classified it based on that.
- Table 6: Please replace your Chinese word with or, e.g., <10 or >100, in the last column in Table 6.
Response: Thank you for your comments, we have already replace Chinese word with or.
- Overall, this paper was written in a form that seems a little bit wordy. If possible and applicable, the authors should consider refining and polishing this manuscript by shortening the lengthy expressions and redundancy. By doing so, the presenting quality of this work will be massively enhanced.
Response: Thank you for your comments, we have revised the manuscript accordingly.
Author Response File: 
Author Response.pdf
Reviewer 2 Report (New Reviewer)
Comments and Suggestions for AuthorsIt is a good paper discussing various hydro geological aspects various part of the U mining region . But I feel some more information and discussion are required on-is it working or proposed mining site, GW pumped out is going to be for irrigation , drinking etc.,what is the pH of the GW , clay types and their weatherablities are to be known, statigraphy of ore in relation to Aquifer lithology, confined aquifer Pressure ,what are the minor element present along with U in the aquifer that can be leached to GW as well , etc., need to be added , next relevant literature of similar environment globally having same issue may be compared and discussed
Author Response
Dear Reviewer,
We sincerely appreciate your constructive comments. We have revised the manuscript accordingly and responded to your comments point-by-point as listed below. To facilitate reviewer and editing viewing, we have used normal blue font for our response and highlighted text for changes made to the revised manuscript. We hope the revised manuscript is found suitable for publication in Water.
On behalf of all the authors,
Dr. Wanjun Jiang
Tianjin Center, China Geological Survey
COMMENTS TO THE AUTHOR:
Reviewer 2
It is a good paper discussing various hydro geological aspects various part of the U mining region. But I feel some more information and discussion are required on-is it working or proposed mining site,
GW pumped out is going to be for irrigation, drinking etc.,
Response: Thank you for your comments, the purpose of the drilling is to gain a understanding of the regional geological conditions, while the purpose of the pumping test is to obtain hydrogeological parameters. Additionally, we have supplemented the well information in Lines 182-185.
what is the pH of the GW, clay types and their weatherablities are to be known,
Response: Thank you for your comments, the pH of the GW in the study area ranged from 6.91 to 8.5. And the weathering degree of clay minerals including montmorillonite, illite etc in the study area is relatively high according to our existing drilling core data. Additionally, the hydrogeochemical research or water-rock interaction simulation related to uranium mineralization will be carried out in the follow-up work.
statigraphy of ore in relation to Aquifer lithology, confined aquifer Pressure ,what are the minor element present along with U in the aquifer that can be leached to GW as well , etc., need to be added ,
Response: Thank you for your comments, the proposal has significant academic value. We discussed the relationship between uranium concentration in groundwater and the metallogenic effect. Based on your suggestions, we need to conduct further experimental research. In subsequent work, we will continue to conduct related research.
next relevant literature of similar environment globally having same issue may be compared and discussed
Response: Thank you for your comments, we have revised the manuscript accordingly.
Author Response File: Author Response.pdf
Reviewer 3 Report (New Reviewer)
Comments and Suggestions for AuthorsI am grateful for the invitation from the Water journal to review the manuscript titled "Comprehensive study on hydrogeological conditions and suitability evaluation of in situ leaching for sandstone-hosted uranium deposit in Erlian Basin." I have carefully read this manuscript and, overall, it is of high quality. The topic is clear, the structure is logical, the data are abundant, the figures and tables are well-illustrated, the English writing is standardized, and the conclusions are credible. This is a commendable piece of work that is significant for elucidating the hydrogeological conditions and metallogenic mechanism of sandstone-hosted uranium deposits. Therefore, as a reviewer, I recommend its publication after minor revisions. The main modifications include:
1. The study area depicted in Figures 4, 5, and 6 should be indicated on Figure 1.
2. If possible, add a conceptual model figure at the end of the paper to facilitate the reader's understanding of the main innovative insights presented in the study.
3. There is limited well information provided in the manuscript. It is necessary to clarify how many wells' data were used to construct the plan and cross-section maps to enhance the credibility and accuracy of the figures. Moreover, the wells mentioned in the text should be displayed on the corresponding plan and cross-section maps.
4. The phrasing "in situ leaching" used in the title may or may not be accurate, and it is necessary to refer to authoritative foreign literature to confirm its correctness.
Thank you for considering these suggestions.
Comments on the Quality of English LanguageMinor editing of English language required.
Author Response
Dear Reviewer,
We sincerely appreciate your constructive comments. We have revised the manuscript accordingly and responded to your comments point-by-point as listed below. To facilitate reviewer and editing viewing, we have used normal blue font for our response and highlighted text for changes made to the revised manuscript. We hope the revised manuscript is found suitable for publication in Water.
On behalf of all the authors,
Dr. Wanjun Jiang
Tianjin Center, China Geological Survey
COMMENTS TO THE AUTHOR:
Reviewer 3
- The study area depicted in Figures 4, 5, and 6 should be indicated on Figure 1.
Response: Thank you for your comments, the study area has been indicated in blue dashed lines on Figure 1.
- If possible, add a conceptual model figure at the end of the paper to facilitate the reader's understanding of the main innovative insights presented in the study.
Response: This is an idea well worth taking. But the study mainly identified the favorable hydrogeological conditions related to uranium mineralization from the macroscopic perspective of regional scale, and evaluate suitability of in situ leaching (ISL). The purpose of this study is to provide scientific basis for the delineation and exploitation of uranium ore targets. Therefore, the microcosmic metallogenic mechanism or model were not reflected in this study. For example, hydrogeochemical research or water-rock interaction simulation related to uranium mineralization. According to the suggestion, the above related studies will be carried out in the follow-up work.
- There is limited well information provided in the manuscript. It is necessary to clarify how many wells' data were used to construct the plan and cross-section maps to enhance the credibility and accuracy of the figures. Moreover, the wells mentioned in the text should be displayed on the corresponding plan and cross-section maps.
Response: Thank you for your comments, we have supplemented the well information in Lines 182-185.The wells mentioned in the text have been displayed in Figure 4.
- The phrasing "in situ leaching" used in the title may or may not be accurate, and it is necessary to refer to authoritative foreign literature to confirm its correctness.
Response: Thank you for your comments, the application of 'in situ leaching' remains a topic of considerable debate. We have conducted a comprehensive literature review and employed contemporary terminology.
Lu, C.; Xiu, W.; Guo, H.; Lian G.; Yang, B.; Zhang, T.; Bi, E.; Shi, Z. Multi-Isotope Based Identification and Quantification of Oxygen Consuming Processes in Uranium Hosting Aquifers With CO2 + O2 In Situ Leaching. Water Resources Research. 2023, 59, e2022WR033980. https://doi.org/10.1029/2022WR033980
Lu CS., Xiu W., Yang B., Zhang HY., Lian GX., Zhang TJ.,Bi EP., Guo HM., Natural Attenuation of Groundwater Uranium in Post-Neutral-Mining Sites Evidenced from Multiple Isotopes and Dissolved Organic Matter. Environmental Science & Technology. 2024, 58, 28, 12674-12684. https://doi.org/10.1021/acs.est.4c04498
Seredkin, M., Zabolotsky, A., Jeffress, G., 2016. In situ recovery, an alternative to conventional methods of mining: Exploration, resource estimation, environmental issues, project evaluation and economics. Ore Geol. Rev. 79, 500–514. https://doi.org/10.1016/j.oregeorev.2016.06.016.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report (New Reviewer)
Comments and Suggestions for AuthorsMinor revision.
1. Line 19: K for hydraulic conductivity and Q for well discharge. You reversed both.
2. Lines 23-24: You reversed K and Q as above.
3. Line 175: Citation in Number [33] should be moved into Lines 187-192.
4. Figure 4: The quality of Figure 4 still needs some improvements. The legends for both subplots are not readable.
5. Line 590: After three concluding points, you can reflect on your work by listing a few limitations and writing up prospects for future work.
Comments on the Quality of English LanguageMinor edits.
Author Response
- Line 19: K for hydraulic conductivity and Q for well discharge. You reversed both.
Response: Thank you for your comments, we have revised this issue.
- Lines 23-24: You reversed K and Q as above.
Response: Thank you for your comments, we have revised this issue.
- Line 175: Citation in Number [33] should be moved into Lines 187-192.
Response: Thank you for your comments, we have revised this issue.
- Figure 4: The quality of Figure 4 still needs some improvements. The legends for both subplots are not readable.
Response: As suggested, we have adjusted the size of the legend.
- Line 590: After three concluding points, you can reflect on your work by listing a few limitations and writing up prospects for future work.
Response: Thank you for your comments, the microcosmic metallogenic mechanism or model were not reflected in this study. For example, hydrogeochemical research or water-rock interaction simulation related to uranium mineralization. The above related studies will be carried out in the follow-up work.
This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsReviewer Comments: Paper No. - Water - 3082681
Comment No 1……… [ Page no 01 / Line No 15]
Define abbreviation…ISL >> it is ‘insitu leaching’ I feel .
Comment No 2……… [ Page no 09 / Line No 316]
There is no technically correct word like 'uranium aquifer'... 'limestone aquifer' or.... 'magnesium aquifer'. The author should have used words like............ unconfined aquifer or confined aquifer instead of the word 'uranium aquifer'.
Casual use of aquifer types (Unconfined aquifer /confined aquifer) must be avoided. It is suggested that this genuine mistake be rectified throughout the manuscript
Comment No 3……… [ Page no 15 / Line No 504-506]
Author wrote that ... The in-situ hydrogeological conditions of sandstone-type uranium deposits are comprehensively evaluated based on a comprehensive reference to 05 major categories of indexes. Again in the abstract (Line no 19 & 20) the author wrote that …..’the aquifer was beneficial to migration and transformation of uranium due to relatively better permeability and faster runoff rate’.
Since it is a Uranium deposit, the radioactivity in groundwater is an important factor. It is therefore suggested to please add one paragraph in the manuscript text on “groundwater and radioactivity”. A short paragraph will make the overall content as ……a comprehensive evaluation. All other hydrogeological parameters are OK. Please add some more relevant research papers that deals with radioactivity in groundwater due to radioactive ore /mineral ( chemical analysis ).
Comment No 4……… [Page no 18 / Line No 580 & 586, 587 ,589, 590]
Delete word ‘insitu’ because technically mining is either ‘surface mining’ or ‘underground mining’. With the word ‘insitu leaching’… the ‘insitu’ additive is correct.
The author is suggested to make the use of the word ‘in situ’ cautiously.
Comment No 5………[Page no 15,16,17]
Table no 5, 6 and Figure no 6 are excellent.
Sd/-
(Reviewer 1)
Comments for author File: Comments.pdf
English is OK. No problem
Reviewer 2 Report
Comments and Suggestions for AuthorsThis article focuses on the very interesting and topical problem of uranium mining by leaching. This method of uranium mining requires a very good understanding of the hydrogeological conditions. The authors used available data to determine the thickness of the ore body, groundwater flow directions, groundwater TDS variations and groundwater types. They conducted pumping tests in two wells to reliably determine hydraulic conductivity.
The research results presented are certainly necessary to make a decision on uranium mining by sandstone leaching, but they are not sufficient.
In my opinion, a numerical groundwater flow model should be carried out in order to make a final decision on how to exploit the deposit. The article lacks the results of such a model.
Detailed comments
1) Section 2.1 - please add information on the amount of atmospheric precipitation.
2) Figure 1 - please add: (1) on the map, the line of the cross section shown below, (2) explanations of the symbols shown on the cross section, (3) the location of the wells from Tables 2-4.
(3) Formula 1 - please change the description of the Q symbol - well discharge. Also check the units. If there is a value of 0.366 in the formula, then K should be in m/s.
4) Table 1 - It is not clear what is meant by the phrase "Confined Head" - depth of aquifer or hydraulic head. Please write it clearly.
5) Chapter 3 - There is a lack of description of TDS measurement methods and methods for analysis of major groundwater elements such as Na, Ca, Cl etc. The interpretation of the results of these measurements is included in Chapter 4.
6) Table 4 - Please add a column for the thickness of the aquifer at the well site.
7) Tables 2-4 - I propose to change the column description - water yield to well discharge. Specific inflow to rather specific discharge of a well.
8) v. 484-486 - the waters studied are also of the HCO3-Cl-Na type. The dominant anion in such waters is bicarbonate. Please add a comment to the text on the origin of HCO3 in groundwater.
9) It would also be useful to write clearly in the text whether uranium accumulation is still occurring today or whether the process of deposit formation was completed in the geological past.
