The assessment of water treatment plant efficiency depends on the raw water characteristics and the characteristics of the treated water as compared with the regulatory standards which in most cases is the WHO standards or respective country legislations. The first thing, in my opinion, is to determine the physical, chemical and bacteriological character of both the raw and treated water thereby determining the percent removal for each parameter. Finally, assess the final treated water with the respective standards or allowable limits.

Hello Pradeep M Hodlur

Please check the resources

https://www.nap.edu/read/9595/chapter/13

Thank you Edwin Kimutai Kanda and Nirmala S.V.S.G madam

Sir,

Even you can refer the ISO specification for potable water.

Dear Pradeep,

Here are some documents that may be useful to you.

http://www.neiwpcc.orgwww.neiwpcc.org/ppcpconference2007/ppcp-docs/PaulStackelberg/Stackelberg%20et%20al%202007.pdf

http://www.who.int/water_sanitation_health/dwq/9241546301_chap5.pdf

https://www.epa.gov/sites/production/files/2015-08/documents/wastewater-guide.pdf

https://pdfs.semanticscholar.org/2dcd/965372f8ee9d7a3a347b64ff4240ddb6ccde.pdf

http://www.ajol.info/index.php/wsa/article/view/76795

With my best regards

Prof. Bachir ACHOUR

Dear P M H , Abiding with notings by E K K .. you need to place what standards you wish to maintain for the final water as regards to its charecteridtics. Having dealt with afresh water made from sea water on ships. Can simulate the parameters.. as per WHO standards. Ideally it comes to produce copious distilled water and add additives as desired..My earlier notings on water quality in these commuication may be referred. To say that C A T S .. criteria.. i.e C stands for clean and clear without physical impurities..A Alkaine to suit to drinking quality. T-  Tasty to have desired salts and nutrients.. duly aerated with dissolved O2. S - sterile.. bacteriologically remdied using UV filters ..etc..  pl follow these simple principles anđ practices.. w wshs .. 

Thank you Rudragouda Kubergouda Patil, Bachir Achour, And Ajit Seshadri for your Inputs

you can refer the ISO specification for potable water.

what is said above is very real and pertinent to your question.

A parameter that is not often seen is EDC. Water treatment technology still treats the old nice clean river water.

We have moved on from that quality water, nowadays most rivers are heavily polluted and one needs to treat accordingly. The presence of EDC can be prolific, as a lot pass through sewage treatment plants and then get abstracted from the river into a simple flocculation settlement and filtration plant.

More and more work is being done on EDC and the removal of it. EDC can have disastrous effects on aquatic life and what will the effect on humans be?