N

Comments

Response

Reviewer 1

1

I am totally against your opinion. The water obtained after rain sloughing can have several applications, as long as it falls within the norms. In drinking water some parameters must have up to: Al 200ug/L, Mn 100ug/L, Zn 5mg/L, Cr 50ug/L, Zn 5 mg/L, Cu 2mg/L turbidity 5 NTU, 500 mg/L of soluble solids.... that is, many of these are met by the norms shown in Table 3... only Pb and organic substances would be out of this water quality and you also did not mention the Hg content limit (very dangerous)

Therefore, this should and can be used in several applications, just ensuring that it is meeting the current quality standards for each type of water. In the case of the aforementioned table, this water should not be used for human consumption, as there is no analysis of the presence of lead and organic substances and, the mercury content is higher than the standards for drinking water.

We do agree with the reviewer that regardless the water source (natural water, rainwater, reclaimed wastewater, etc.) the water quality should always meet the requirements for the particular usage type. It is true that in case of using water for drinking water purposes there are well set national standards. To make this more transparent in the paper, we added a paragraph in the revised paper (see lines 296-301).

However, the paper discusses also other types of rainwater use, in particular those which can contribute to better urban water management and in line with the circular economy, but which are not currently well regulated. For example, use of rainwater for irrigation of small plots or for toilet flushing, etc. (see lines 484-486, etc.). The paper also discusses the need for consistent international regulations to mitigate health and environmental risks from such applications (see Section 4.2.1). We consider that this is one of the added values of the paper.

2

I suggest that you use more regulations from other countries, as this Ordinance No. 18, it will end up making even irrigation unfeasible using rain as Brazilian communities (and Indians) do

Done. We added some more examples in Section 3.2 - UN FAO requirements (lines 258-265) as well as the standards from two other countries (Table 7)

3

In Brazil, water quality is monitored by CONAMA and Ministery of Heath, such as:

https://bvsms.saude.gov.br/bvs/saudelegis/gm/2021/prt0888_24_05_2021_rep.html

21. BRASIL. Decreto 3.179 de 21 de Setembro de 1999 – sanções aplicáveis às condutas e 384 atividades lesivas ao meio ambiente. Available at: 385 . Accessed in December 10, 2022. 387 22. BRASIL. Lei 9.605 de 12 de Fevereiro de 1998 – sanções penais e administrativas derivadas 388 de condutas e atividades lesivas ao meio ambiente. Available at: 389 http://www.planalto.gov.br/ccivil_03/leis/L9605.htm>. Accessed in December 10, 2022.

Thank you for providing this link. We checked it, but it seems that these requirements refer to drinking water quality. We did not include values for drinking water quality due to the lack of significant differences among the countries (see lines 296-301).

N

Comments

Response

Reviewer 2

4

I think two minor changes are necessary:

row 63: please replace 'steps' with 'parts'

Done. Please, see Section 2.

5

rows 213-227: at least one reference is required

Done.

N

Comments

Response

Reviewer 3

6

The ms lacks synthetic presentation. Authors listed information but did not compile it.

Table 1 is based on 2 publications of 2011. Table 3 on 1. Table 4 on 2. Table 5 (mispelled as Table 1) on the European Standard. Table 6 on the USEPA standard. 

We thank to the reviewer for suggesting strengthening of the presentation of the collected information. We believe that we addressed this comment:

·        Section 3 was revised to strengthen the logical links between different paragraphs and statements.

·        Restructuring in section 3.2 is also done to strengthen the synthetic presentation of the provided information

The information in all tables mentioned by the Reviewer had been collected not only from one, but from many sources. It is our mistake that we had put in the table only the source with the highest and with the lowest reported value. This mistake is now corrected and all used sources are listed in these tables, including the new sources, which were added with this revision.

7

Not an adequate number of references (35) used, for a review. Moreover, authors assert a state-of-the-art analysis, however, only 1/4 (9) of the references were published during last 5 years. Many outdated references  used.

Please, kindly note that the paper was not submitted as a review paper, i.e. its purpose is not to do a comprehensive review. The referred articles (63 in total after the revision) flag the problems concerning rainwater quality, namely that RWHQ is a very dynamic parameter depending on a number of factors, most of them also with dynamic character. We agree that most recent papers should be used even for a review without pretensions to be exhaustive. Thus, we added 28 new references from the last years. Please, note that these new references did not change the already existing main conclusions.

8

Line 390: The phrase "many studies" is used without any citation.

In the revised paper it is now line 402 and references are provided.

9

The ms needs substantial changes

In methods: what is the type of review you have followed? Is it a systematic review? (it would be recommended). 

Please, see above item 7.

10

The attempted "state-of-art analysis" is based on limited papers, many of which are outdated.

Please, see above item 7 - 28 new recent sources were added. But we would like kindly to note that papers issued some more years ago cannot be considered “outdated”, since to the best of our knowledge the level of research up to now concerning rainwater quality is still mostly based on an active monitoring rather than on predictive modelling.

11

The legislative gap regarding the harvested rainwater reuse is a serious issue that has to be addressed. 

Suggestions:

It would be interesting to compare the data and the changes from 2000 to 2022 (European Union Standards). 

We do agree that it will be interesting, but please, see our motivation and understanding on what the scope of our paper is (item 7 above).

12

You could compare the latest EU standards against those by USEPA.

Done. US EPA is included and compared with national legislation in 3 EU countries (see Table 7)

13

You need to analyse a considerable number of articles/ Directives etc. Define the type of review you follow and consider to create a flow chart of the review steps.

Please, see above item 7.

14

The Discussion part includes interesting points which should be the main part of the review. Discussion and Conclusions are expected to put forward a numerical suggestion of standards or limits, in a synthetic approach.

Please, see above item 7. We would like to clarify again that: i) it is not a review paper; ii) putting numerical suggestions of standards or limits requires much more efforts than the scope of this research paper. Please, note that in the paper we are discussing this issue - the lack of reliable data base, which could be used to develop reliable standards (lines 516-525).

15

The ms has potential to be published, but not in the current form. Therefore, I recommend reject and resubmit after a thorough and radical revision and enrichment.

Thank you for all comments of the reviewers. We believe that addressing them contributed to enhancing the quality of our paper. We almost doubled the reference list, including very recent publications. We also searched for other international standards and included them in the paper. We strengthen some of the conclusions.