Fifty-Year Review of Effluent Discharge Trends to the Southern California Bight from Large Municipal Wastewater Treatment Facilities from 1971 to 2020

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Dear Authors,

I found your article to be a valuable source of historical data, and it was both interesting and well-presented. I do have a few questions and suggestions for further exploration:

Do you have any available data regarding the discharge area in the ocean? It would be quite interesting to understand the changes in the ecosystem and related factors.

If possible, please address what changes in treatment plants have contributed to the reduction of these constituents over time.

Are there other chemical constituents that you believe should be addressed in the future? If so, please elaborate on why you think they are significant.

Is there any concern regarding the continued discharge into the ocean, and what does the future hold in this regard? It would be valuable to explore potential consequences and challenges associated with ongoing discharge.

Comments on the Quality of English Language

No issues with the English language. 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

In the manuscript of water-2673514, the authors provided a systematical work regrading to the 50-year review of effluent discharge trends in Southern California Bight. Although the work is OK, i still think the author should make a resivion basing on the following advices.

(1) I think the Introduction had addressed too many historical things/background. It is not clear that why the authors need to do such investigation when comparing with short-term analysis. Why long-term evalucation is important. What can we benifit from this long-term invetigation.

(2) The journal of Water aimed to publish academic work. The author need to state the academic value of this work. Better to exhibite the scientific/academic statement in the backgound section.

(3) The section 4 lack the discuss regarding to the obtained data. What is the driven force for the evolution of each pollutants parameter need to be addressed.

(4) the conclusion need to provide information about the perspectives basing on the obtained results. and show the academic guidance basing on long-term evaluation.

(5) Cite more references related to academic paper to support the revelent viewpoints/findings will be better. 

Overall, I expect the author could provide a minor revision basing on these suggestions. I also hope the auhor could cite the references of https://doi.org/10.3390/polym15122741 the the revised mansucript.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

Dear Authors,

The Authors show that this study is serve as a continuation of SCCWRP’s efforts of characterizing the effluent discharge from the four largest POTWs that discharge to the SCB by providing a long-term analysis of constituents and identifying trends of constituents’ mass emissions that occurred from 1971 to 2020. Their study of the flow and chemistry data of the four largest POTWs between 1971 and 2020 finds that the mass emissions of all constituents drastically decreased, with most constituents experiencing an overall 80-100% reduction, and their measurements were at historically low values in either 2010 or 2020. This study highlights general trends in the constituent loading from all four POTWs, additional studies focusing on the relative mass emissions contributions from each POTW could pinpoint the dominant source of mass emissions for constituents considered in this study. Overall, the estimated reduction of mass emissions demonstrates that the four largest POTWs have made tremendous strides at protecting the water quality of the SCB, making beaches and lagoons safer for local communities and wildlife to enjoy.

 

The description of the work is acceptable. Overall impression is that this manuscript can be recommended for publication after MAJOR revision in Water especially considering the scope and topics of this journal. However, I would like to point out to several details:

 

1. Abstract should answer the questions: What problem did you study and why is it important? What methods did you use? What were your main results? And what conclusions can you draw from your results? Please make your abstract with more specific and quantitative results while it suits broader audiences. Correct the abstract.
2. It is not clear what novelty in paper worth to publish is? Correct this.
3. Please note in the Instruction of the Water for Introduction section and state the objectives of the work and provide an adequate background, avoiding a detailed literature survey or a summary of the results. The Authors did not give the adequate summary of the earlier investigation. Correct this.
4. Captions for figures need to be more detailed and consist of some details. Correct this.
5. Authors should avoid vertical rules in the tables. All tables should be uniform. Correct this.
6. The length of manuscript is not appropriate. I suggest summarizing the actions taken and results please strengthen the explanation of their significance. It is recommended to use quantitative reasoning comparing with appropriate benchmarks, especially those stemming from previous work. This paper should have more reference and deeper analysis. Correct this.
7. Conclusions are poor. In your conclusions, please discuss the implications of your research. Discussions and conclusions must go deeper; it would be more interesting if the authors focus more on the significance of their findings regarding the importance of the interrelationship between the obtained results and sustainable development in the sector context. Correct this.

 

I wish a lot of success to the authors in making this manuscript much better.

With kind regards!

Reviewer

 

Comments on the Quality of English Language

-

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

Comments and Suggestions for Authors

Dear Authors,

 Interesting results are well presented. The description of the work is acceptable. The length of the manuscript is appropriate. Discussion and conclusion is detailed. In my opinion this manuscript can be PUBLISH in Water especially considering the scope and topics of this journal. The authors correct all suggestions that reviewers gave about article.

 I wish a lot of success to the authors.

Regards!

Reviewer