Dear Client,
This has reference to your revision request. All the questions (except for one) have been answered. I have made the answers obvious and done and added a few words here and there to make the answers more prominent. Everything is marked in the two pages of the ‘copy of the report’ which follows this letter. Please go through the same and tell me if you still think the paper needs revision, after reading it. In case you want a revision, I’ll be happy to do it for you but you have to tell me what needs to be revised exactly.
On ‘perchlorate’ and ‘chlorate’
‘Perchlorate’, Chlorate and ‘chlorite’ is the same inorganic chemical group. The difference is only in no of oxygen molecules attached to a Chlorine molecule. This is 2,3 and 4 respectively for chlorite, chlorate and perchlorate. For chloric contamination, drinking water needs to be exposed to the basic compound ( a compound of chlorine and oxygen). Since, oxygen has a valence of 2, it is much more readily available if the oxygen molecules are neutral Chlorite ( ClO2) or Perchlorate ( ClO4 or 2ClO2) then in the reactive state as the Chlorate ion ( -ClO3 ). If you go to the EPA site and search for chlorate in the search bar, the results will show perchlorate in more than 50% of the cases. Hence, you find some terms in the paper with the suffix perchlorate. A survey had been carried out in Phoenix from 2002-2004 where the results I have mentioned are found. The minimum value is zero. The unit is ppb as this was used before the ETA entered the picture.
All the answers to your questions are given in the report. I have marked the answers with foot notes in the enclosed copy. They are not in the same order as in your questionnaire so that the report has a logical cause –effect sequence from the start to the end. I can put them in the order that you have asked the questions, but the result will be more like a Q&A paper than a report. There won’t be any logical sequence of thought.
Please find your questions below with a suffix no and color coded. The answers in the report have the same color code and suffix no.
I had missed one question i.e. water source in Phoenix.
Questions 3 and 6 have an only one line answer. That is because both the questions are basically the same about the treatment process. No other data could be found in the EPA website. This is because the EPA is yet to regulate the chlorate family as a contaminant and the same will be done only in 2016. I could have answered from other sources but I wanted to refer to the EPA site only.
*What are the Highest and Lowest Levels Detected (Phoenix only)?1
What is the water source (Phoenix only)?2
*Is the city in compliance with SDWA regulations (Phoenix only)?7
*What is the TT- Treatment Technique?3
*What are the Potential Health Effects from Exposure? 4
*What are the Sources of Contaminant in Drinking Water?5
*What method is used for testing and analysis for the contaminant? (not just the method number, but a description of the method)6
For the answers , pls refer to page 3 and page 4 of this paper . The answers corresponding to the questions have been marked and coded the same as the questions.
I have made some minor changes.
Please revert with your opinion. If you say yes, I will remove the colors etc. and upload the paper. However, if you want further revisions, then please tell me what to revise specifically.
Apologies for your inconvenience
Best Regards
Chlorate and other contamination of Drinking Water in Phoenix, Arizona
EPA (Environmental Protection Agency) is a Federal Government Organization, responsible for protecting and maintaining human health and for protecting the environment from damage from human activities or disasters. The EPA does this by framing rules and regulations towards that end, based upon laws passed by the Congress. Water is a vital resource for human beings as our body parts require water to work as they are supposed to do. Drinking Water is therefore required to be separated from any contaminants which may get mixed with it and affect our health adversely. Drinking Water contamination is therefore a serious Public Health issue which if not taken seriously results can result in deadly epidemics. The treatment and purification of water as a whole is a vast subject. In this paper, we will only talk about drinking water contamination in the city of Phoenix, in Arizona State.
Drinking water contains different contaminants in it. The presence of a contaminant does not necessarily mean that the drinking water will lead to a public health issue. The EPA decides whether a contaminant should be regulated or not depending on the SDWA (the Safe Drinking Water Act). The SDWA is the main statute that ensures that water consumed by Americans is perfectly safe health wise. Drinking water supply in Pheonix is as per the Safe Drinking Water Act (SDWA) standards 7
As per the SDWA, the EPA has made two lists up to now, named CCL1 and CCL2. From these two lists, about 90 compounds have been marked as compounds deserving additions to the regulatory list. Chlorates are mentioned prominently on paper with the CAS (Chemical Abstract Service) of 14866-68-3. As of now, Chlorate is an unregulated contaminant of Drinking Water. However, it has been incorporated into CCL3 and by 2016; chlorate should be a regulated chemical contaminant.
The Maximum Contaminant Level (MCL) for Chlorate has not been finalized yet as testing and research is going on and it is the same story in case of Maximum Contaminant Level Goal (MCLG)1. However, what has been established is that chlorate exposure is non-carcinogenic. Perchlorate salts have been found to adversely affect the thyroid gland by reducing production of thyroid hormones. Other details can only be expected from the EPA when it releases CCL3 in 2016.4
Chlorate compounds are used in agriculture as defoliants or desiccants .They are used for drinking water disinfection such as chlorine dioxide. Chlorate contaminants find their way into drinking water from run-off ground water and also from excessive use of Carbon di-oxide to purify the water.5 The best way to treat Chlorate compounds at this stage seems to be through a hypochlorite solution. However, research continues and there is no reason not to believe that treatment of chlorate in drinking water can be carried out by easier processes.3and 6
We have been able to access records pertaining to Perchlorate (chlorate with four Oxygen atoms) for the city of Phoenix. Perchlorate can be found at groundwater and well water (shallow level). The city of Phoenix authorized perchlorate testing for three years from 2002 to 2004. In well water readings and in surface water, the same thing happens i.e. presence of perchlorate salts is almost nil in 90% of the cases and in the balance 10% , perchlorate values were found to be 5.2 ppb (parts per billion) to 5.4 ppb which is much less than the specified maximum value of 14 ppb. 1 Water sources in Phoenix is ground water and run-off sub-surface water from shallow wells, etc.2
Note:
- All information given above has been researched from the EPA web site’s water subpages http://water.epa.gov/
- Chlorate and Perchlorate is the same contaminant in CCL3.
