cheap water Treatment methods 2

[gomirage]

Hello everyone,
Our client is buying water from a water utility and thought that he was paying too much. He would like to study the alternative of installing a well with a small treatment station.
We are investigating the possibility of drilling a well and install either a membrane treatment station or a simple chlorination treatment.

He already has a tank and a pressure pump station in-line. What we will need is only a submersible pump and a treatment unit.

Anyone with experience in well water treatment ? I will appreciate to hear your thought about this. I will also appreciate to have a good quickly accessible reference on intalling water treatment station for water wells. In particular the parameters to consider.
The system average demande is 5 GPM and a maximun peak of about 15 GPM.

thanks

chris

 

[semo]

You have asked a big question that doesn't have a direct solution.

First off, you need to know what the well water quality will be. Will it be within MCL's and Secondary Standards?

You will need to actually drill a well and analyze the water to find out what it's constituents are. You can look at nearby wells and get an estimate; but, you can't be sure until you pump some water out from that location.

We have wells in our area that are alluvial/deep unconsolidated (sand) wells and consolidated (rock) wells. Each produces different quality waters (even with similar construction and in the same geologic formation), some of which do and some do not require treatment.

Once you have your water analysis, you can determine what if anything will you have to treat (iron/manganese, hardness, nitrates, radionucleides, sodium, nitrites, hydrogen sulfide, etc.) Each requires a different type of treatment. If you don't have to treat anything, you might just need to add chlorine (if you even have to do that in your region).

If you can do a little more homework on the local water quality, we might be able to give some advise on it's treatment.

I've not seen many situations where installing your own system is more affordable than purchasing water from a regional supply. Having their own supply means that they have to pay the electric, chemicals, repairs, operator, clerk, tank/storage maintenance (painting), testing, testing equipment, loan payments for the construction of the system, annual operators licensing/schooling, etc. They also have to locate financing for the system and they are then legally responsible for the quality of the water (not the regional supplier like it is now). The state may even require that they have backup pumps and wells. That increases the construction cost.

 

[semo]

Here is a thread on flow rates too.

thread164-80061 don't know your system and how you arrived at your flows; but, your peak flow looks a little low compared to your average flow. If you don't have any storage, you will need to look at instantaneous peak.

I'm correcting a subdivision right now where someone underestimated the flow rates (don't think they had the experience to know better) and now some high elevation homes don't have any water.

 

[PUMPDESIGNER]

semo is correct in all that he said.
I have however worked on overseas projects where they had not standards but their own standards.
They just started with a basic UV treatment.
Did fecal coliform tests once per week.
After awhile they started seeing coliform so they installed more equipment until they got it licked.
They were in charge of their own system and cared a whole lot so they were OK I suppose.
But there was no engineer who would accept responsibility, and we just supplied the pumps and electronices, and then shipped them the equipment they requested, so we had no responsibility.
So bottom line for them was, they were responsible for their own safety and health, good deal for them because they were smart people.

But we must also remember that there are hundreds of thousands of systems on this planet and in the US where the people are responsible for their own health, and they use ground water daily with few problems, and they monitor constantly just to be sure. Many of those systems have no treatment whatsoever, and none is needed. But those systems are very rural and away from civilization, and no engineer is going to accept responsibility, and strangely, I think probably many engineers have such systems but are careful to test once in awhile.

PUMPDESIGNER

 

[gomirage]

Thanks for your suggestions. In fact, i am more interested in a reverse osmosis. After checking on the water qulity it appears that a simple chlorination won't do it.
Since we have a tank i am investigating the possibility of installing the RO unit right after the well, and store the treated water in the tank. Thus, i can treat at a fix rate (say 5GPM) and store in the tank which will be able to deliver the peak flow(15 GPM for example) to the distribution system.

However, i need to do some reading on the matter before trying anything. I will be very grateful if anyone can provide me with a case study of such system.

 

[semo]

I'm not really versed in the RO process, am preparing to learn with a pilot study soon.

The RO will remove basically everything. You will have some bypass to keep some hardness in the water and will have a continuous waste stream. You will also have chemical addition to condition the water. I know high silicates can cause problems with this type of treatment.

Your locationing of the skid sounds appropriate; but, with a ground storage tank, you are double pumping which increases costs. As well, the RO units are not cheap and the chemical costs could add up.

The RO will require an operator to keep control on the chem feed rates, as well as the membrane acid washing.

I would post in the Chemical - Membrane area and get more info on RO as well as other membranes (nano, ultra, etc.)which may handle your situation.

 

[GarySCWSVI]

RO will provide a very high quality water from a contaminants standpoint. However, they also require pretreatment and close monitoring. They should not be used on microbiologically contaminated water to remove microbes. In addition, RO water quality is not required in the majority of regular water usage. They are ideal for producing water for drinking and for ice making. Also they add to electricity costs to run their pumps. This would be added electricity usage of the well pump and the pump after the storage tank.

You may want to post the results of the water analysis here and we can make suggestions for treatment. Without knowing what is in the water we cannot help.

Gary Schreiber, CWS VI
The Purolite Co.

 

[Digiorno]

You should contact the people at Crane Environmental if you're on the east coast or Membrane Systems Corporation on the West Coast.

They both specialize in small RO systems and can either provide you services directly or direct you to vendors that can supply cheap and appropriate systems for your use.

http://www.cranenv.com

http://www.membranesystems.com

Another vendor that you may want to contact that has pre-built systems is

http://www.ampac1.com.

many of their products are for residential use, but they can supply something for this use as well.

 

[JStephen]

Do you know what regulations affect the well drilling/ water rights? I know in many cases, water tables are dropping, and local utilities are having to switch to surface water systems in lieu of well systems. So you might be prohibited from doing the well, regardless of cost.

Secondly, I suppose somebody has sat down and discussed this with the local utility? If it's a large-city system, that probably won't help. But if it's a major user on a minor system (which is where the cost would tend to be highest), you would think they could cut you a deal. You might also check if you can draw water at off-peak times and get any discount from them.

A number of the local utilities around here (IE, cities) buy water from a water wholesaler (regional water supplier). If your local utility does, you might check into the feasibility of buying directly from the wholesaler.

 

[bimr]

If you are located in the US, a small well is going to cost you about $5,000 and water treatment is going to cost another $2,500. If this is a residence, the cost for well registration and compliance issues is probably minimal.

There is nothing magical regarding well water treatment versus other types of water treatment.

Most homeowners don't have the time and resources to properly service all of the gadgets in their homes. Operating your own water treatment applicance is just another headache for the homeowner.

The operating cost for the proposed water treatment system is probably going to be comparable to the cost of purchased water. From my experience, the cost of purchased water from a utility is a minimal expense. Why would anyone worry about that?