Borewell Water Treatment

I think you need to contact a local specialist. There are some results in your tests that provide multiple interpretation.

(For instance: Is the turbidity the result of the TDS material (in which case filtration would seem the path to follow) or is it chemical colouring due to dissolved metalic ions?)

The assay also seems to be missing something as there are a lot of metallic ions listed without balancing positive ions in an almost neutral pH.

The local people can also advise routine maintenance expectations on the equipment, since from what you have described, the filters will accumulate material over time.

I am giving a GA as you recognize the limitations of the testing completed. I would also suggest more sampling for a more complete picture of the water tested. Consult with a local expert who is familiar with ground water chemistry and microbiology. The following may help:

Complete metal scan (Mn, Mn total, Fe, Fe total, Ba, U, As, Pb, ...and as suggested by professional)

Complete bacteria testing (total coliform, fecal coliform, E.coli, F. Strep., HPC)

UV transmissibility

Trace nutrients (include; TOC, Total P At very low limits, NO3, NO2, NH3, Total Kjeldahl N )

Physical parameters; pH, Color, Turbidity (at the well head if possible), temperature at the well head, conductivity

H2S

Major ions to balance within 5%

Calculate Langlier Index.

Each location may require different parameters. Location is a key and so will talking to a local person very knowledgeable in local conditions. Local Chemical industry use, and local agricultural practice may be important. Also consult with an accredited lab. They have a wealth of local information and will provide the appropriate sampling bottles to preserve the parameter to be tested.

OP, it is very difficult to recommend treatment without a good picture. All we can really say is the water is hard based on the information provided. Hard water is OK for drinking (as long as there is nothing else that may be harmful) but is not good for washing or other uses. Bypass a drinking water tap to allow it to be hard. I am not sure why the turbidity is high but it may have more to do with other parameters not tested, well construction, or even the temperature change from the well to a lab. As the water warms, more calcium may come out of solution. Metals as suggested can be in the water and create some turbidity. More testing is required and we have very little knowledge of the water or well construction to make treatment recommendations.

Welcome to CR4.

The water is fine for drinking as it is. Note that using a softener will increase the sodium content of the water at a ratio of two sodium ions for one calcium ion.

yup..the water seems to be acceptable to drink as it is. however, wouldnt the high hardness & calcium content give some weird taste?

yes, i am aware of the increase in sodium..any idea how to handle this?

yup..the water seems to be acceptable to drink as it is. however, wouldnt the high hardness & calcium content give some weird taste?

It will taste like mineral water, which is what it basically is.

yes, i am aware of the increase in sodium..any idea how to handle this?

Reverse osmosis or deionization. Both are very costly though. Also, prolonged drinking of high purity water is bad for the health because it will leach out vital minerals from the body.

Another possible solution: deionize only some of the water and use it to dilute the rest to an acceptable sodium level.

great idea!

I agree that from the analysis given it's OK to drink. The sodium, chloride and hardness are within normal tap water levels.

But there's no reference to bacteriological data. I would get some tests done, and in any case give it a dash of chlorine before drinking it.

Codey

total coliform is 110 CFU/100ml & its positive for e-coli. yes, i will include Cl2 dosing before the storage tank

Ashot of Jack Black -- JHF

It sounds as though a boiler would be more fastidious than a drinker.

Nano filteration or Reverse osmosis are the simplest options to your requirement. Call a local membrane service personnel, conduct pass trilas, check the output water qualities and conclude yourself

very true..but might be an overkill on cost

It is always worthwhile putting a depth filter upstream of any other process or user. The desired flowrate determines equipment selection and sizing.

Reverse osmosis would be significant overkill for this water- and way too expensive for very little benefit.

You would probably quite satisfied with only an activated carbon filter.

There is nothing mentioned about biological contaminants- algae, microbes, etc. For added safety, you might consider an ozone treatment- cheaper in the long run than UV, and will tend to oxidize some of the metallic ions and bring the pH closer to 7.0 (fantastic for bathing, in my opinion). Properly-installed UV will result in limited flow, and the efficacy decreases rapidly with time (most legitimate manufacturers recommend replacing bulbs annually due to shifting output wavelength over time- not an inexpensive option). The turbidity would also tend to limit the efficacy of the UV treatment. A poorly-installed UV system can actually increase biological contamination because the oxidized organic material provides a food source for the little buggers that sneak by...

Neither ozone or UV will provide protection for long-term storage...

i thot so too..GAC would be sufficient.

total coliforms are about 110 CFU/100ml and positive for e-coli. looking at storage of about 5-7 days. you think i should just use chlorine instead?

Is the storage protected? Can rodents or other vectors find easy access? GAC will only serve to provide a good microbial breeding ground an I would avoid it unless all bacteria are neutralized. Is the source of the bacteria known? Is the well contaminated or is it just the storage tank? Does the well fill the storage tank? And if so where is the tank and how is it getting contaminated? Chlorine with 7 days retention or contact may create some unknown issues if the Total organic carbon content is high. Still many questions before suggesting any treatment.

storage is well protected..even from rodents. bacteria is from the well itself.

water from well is pumped into a raw water storage tank. this tank will be next to well. there will also be treated water tank after the WTP

First, I am assuming that the water is intended for consumption as potable water.

If the well is GUDI or producing Groundwater Under the Direct Influence of surface water and is a public water supply then that well is mandated to be treated as if it is surface water. The chemistry and the microbiology will fluctuate with many factors and sampling now is a serious issue. Protection of the well head is very important.

The 7 state (great lakes) and Ontario have set up a committee that has mandated that these type of wells have chemically assisted filtration and disinfection meeting CT values with chlorination. If trihalomethane (THM) or haloacetic acid is present then some sort of further control is required. Chloramination or reverse osmosis is often used to eliminate the issues with chlorinated organic material. Sometimes on smaller systems a 1 micron (NSF approved) may be supplemented for the chemically assisted filters. You would want to protect the 1 micron filter as it is easily clogged and expensive if it is replaced frequently. It cannot be cleaned. More sampling with better parameters is suggested.

If the well is intended for private use, I would suggest that you may get away with 1 micron filtration, preceded by staged filtration. Of course reverse osmosis is effective and accepted by most authorities. Activated carbon is sometimes used to reduce TOC but is not as effective when trying to remove THM or HA. In fact your carbon may have to be rebedded too frequently to warrant such treatment for THM. Rebedding is the replacing of the GAC with new GAC. I have always found that it is impossible to effectively clean GAC and in fact may not be allowed. UV is a good final step and can be sized for most uses but should meet the criteria outlined for UV by NSF.

I am not trying to be a prig but I thought you may need better information. Especially, if approval is required.Water treatment needs to be treated seriously under any circumstance.

Noted..thx for the advice!

We have been very successful using ozone on water stored for months, by setting up a circulation system that injects ozone on periodic basis. Mostly used with raw rain water, which is a bit cleaner than your well water. Ozone has the advantage of no nasty chemicals or by-products such as what one gets when using chlorine, and ozone is actually a more effective oxidizer than chlorine (according to the EPA Alternative Disinfectants and Oxidants Guidance Manual- EPA 815-R-99-014 (available in *.pdf on line from EPA). Chlorine residual lasts longer than ozone, though, which is why one needs to keep repeating the treatment.

High NTU Values (>1.0) are a possible indicator of parasites.

The more minerals in the water, the better for the body. With the exception of the high NTU, looks good.

You last mentioned positive on Bacti. Chlorine can handle bacti. Prolong contact with chlorine for parasites, or, ultra filtration - RO. UV kills to cell walls, best sterilization method.

Depends on your volume to determine economics.

Goto USEPA website. The list of maximum safe drinking water contaminants are listed. Again, positive on Bacti on more than one sample plus high NTU is the concern. Otherwise........... looks good.

From your description of the presence of coliform and other items, the test results may be meaningless.

The presence of coliforms tends to indicate interaction with surface water and thus the opportunity for variation in contaminants depending upon surface weather conditions.

You will need a system that can cope with all reasonable possibilities and not just the "snapshot" that you have from this one sample.

Also, I see no assay results for Lead or Arsenic in your initial assay. Does that mean they were not present, or not tested for?

tested for lead & arsenic..not detectable

eddierizz It would beneficial to all if you could provide the complete set of results. You released a few in you opening question and then later mentioned the bacteria. Now we see that you did an arsenic and lead. What else are you not telling us? Better information of the well and lithology would also help. How deep? How much Casing? Material drilled through? Where is it located with regard to septic systems, agricultural disposal, or potential industrial waste? So far, what you have told us indicates serious issues with the well construction and/or location. When you say bored well, what exactly does that mean? Sometimes pictures help. I am sure I would not make any suggestions for treatment based on what we know as of now. In fact I would question the viability of the well as a source of potable water. There are just too many variables and unknowns in raw water quality and sampling. One snapshot, as put by justanengineer is exactly what we know and that is diddly squat.