Dear Authors

Thank you very much for the comments to the reviewers, and the email update outlining further details of the suggested improvements. I am satisfied the proposed revision will address the concerns and look forward to seeing your revised manuscript uploaded.

Please also provide a track changes version to help us follow the revisions.

Many thanks
Matt

Dear Authors,

Thank you for the revision, and your repsonses to the reviewer comments. I believe the manuscript has been significantly improved by these changes and is suitable for publication.

In finalising your upload, I have a couple fo small suggestions for your consideration:
* Abstract Line23: I find this line a little awkward, after the comma where it says "yet where aluminium ..." ... I wonder if you could re-word slightly and/or strengthen this "aim" statement?
* Abstract Line32: "Our results demonstrate that elevated Ali concentrations in Nova Scotia pose a threat" - could you add *continue to* after Nova Scotia, to emphasise that the problem hasn't gone away?
* Results Line 194: Given it is a joint results/discussion, I wonder if the section title for 3.1 could be "Prevalence of Al_i", to more clearly make the "take home message" from this section?
* Conclusion Line 328: You refer to a new hydrological/Al pathway. Is it a "new" pathway never mentioned or this study emphasising the significance. If you think it is really overlooked then this is fine, but I'm just checking youre not overstating.

Overall, I think the paper reads really well and makes an important contribution to catchment hydro-chemistry.

Best wishes
Matt