Quality of water for concreting

1. As water isn't acidic, using it for concreting is fine.
2. To reduce TDS by so little for such a large volume of water, use single pass reverse osmosis.

I like to use a Rule of Thumb when it comes to the water quality in concrete: always use clean drinkable water (ie, potable) suitable for human consumption, or in other words, ask yourself IF YOU can actually stomach drinking a glass of the water than buy all means use the water for inclusion in the concrete mixture.

IMHO, I'd avoid R.O. treatment all together because of the principal equipment costs as well as the operational costs will be excessive at a minimum.....

What is the source for this water? Is the water being treated with chlorine or is this level the natural level?

In regard to your water quality numbers and suitability of the water for use in concrete:

1). The TDS may be a little on the high side. Try filtering out the TDS with some sort of sand filtration or DI filtration or activated carbon filters;

2). The chlorine level is definitely on the high side. I'd very very worried about future rebar and ferric-based insert corrosion in any structural member made with concrete using this water. Activated carbon filter treatment will most likely lower this level substantially, OR if the water is being treated with chlorine say for municipal a water system, then somehow inquire with the municipality or operator about reducing the chlorine dosage considerably. For disinfection of water supply in municipal drinking water systems you only need to achieve 0.5 mg/l free chlorine at the dead ends of municipal piping network and slightly higher at interim locations;

3). The Calcium Carbonate level is marginal. If you lower the chloride ion level this value may be affected as well.....and is likely to increase and make the concrete mixture even more alkaline. there are several methods available to reduce Total Hardness levels including injection of more chlorine (which is counterproductive in this water...see above), low-to-mild level acid injection or employment of carbonization process.

4). the Organic and Inorganic Impurity levels seem high and capable of degrading the overall concrete quality....treat with filtration as per Item # 1 above.

NOTE: If you use sand as filtration medium then make sure it is well graded, clean and free of detritus materials and non-acid soluble. There are specific guidelines available that you can use in selecting and testing sand samples such as the "Ten-State Standards".

Just adding my 2 Cents worth...

oppppsss....must fix a typo in my pervious posting at the end of first sentence within Item #3....meant to type acidic, not alk.!!!!

TDS is a measurement of the salts in the water sand filtering will not help.

Potable water is just fine.

There is no need to reduce the TDS by so little, as immediately after reducing it, its use in concrete undoes all the work just done.