Poor Water Quality and Lining 4" PVC Well

[TJanak]

Two related questions here really. Building a house currently and had a new 4" PVC well drilled. Knew it was a gamble as to water quality and results of test are attached. I plan to retest just to be sure. Don't have the report yet from the driller but 165' deep, 1 HP pump. This thing is salty, high sodium. Boron high too, with more chloride and bicarbonates than ideal as well. Funny thing is my plumber asked how I'm going to filter the water to clean it up. Not sure why he doesn't know you can't filter out sodium, chloride, etc. RO is the only option and that won't work for irrigation! I'm considering not using this well because I'm not sure how to effectively use it. We are big landscapers, gardeners, fruit growers, and this water is effectively useless. $7500 down the drain.

About 500' from the house is a 4" PVC well of unknown age that was used for cow water. 60' deep. 1/2 HP 2 wire pump set at 50' or 55', can't remember. It has a 5 GPM choke on it. When i pull the choke out it makes plenty of water, but pumps sand. Put the choke back in, no sand. The water quality from this well is much better. I am seriously considering using it for the house, but have to deal with the sand issue. Sure I can pump into holding tanks at 5 GPM, but would need a lot of storage for lawn and garden irrigation.

Do I have any options for lining this well to screen out the sand? What would be the best route to proceed from here on making this well useable?

Thanks,
Travis

 

[Valveman]

Not much you can do to line or work on 4" casing. But no deeper than it is you might consider drilling close to this well and putting in a proper well screen or perf and gravel pack. Otherwise the storage tank is your best bet. Remember the storage tank will be refilling at 5 GPM while your booster pump is taking out 10 GPM or so. That makes it require much less storage than if the well was not adding 5 GPM all the time. 2000 gallons of storage would let you pump 10 GPM for 6-7 hours at a time. 4000 gallons of storage would let you run half a day. But you will need the other half of the day for the well to refill the 4000 gallons storage. So, if you can irrigate everything in 12 hours at 10 GPM a 4000 gallon storage tank would work.

 

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[Reach4]

I'm considering not using this well because I'm not sure how to effectively use it. We are big landscapers, gardeners, fruit growers, and this water is effectively useless.

https://www.gardenguides.com/how_12340871_salttolerant-fruit-trees.html

A reverse osmosis filter would probably better than de-ionization for you. https://www.necoindustrialwater.com...right-for-your-industrial-water-purification/

 

[TJanak]

Thanks Cary. I know the storage is an option and it may come to that, although in the end that may not be much less expensive than a new 60' well. Can always find a good used 4000+ gal black poly tank though.

So there's no 3" well screen I can line with and use a 3" pump?

Any tips on finding a report on this old well on the TCEQ website? I've looked briefly but I don't really follow their organization (or lack thereof).

Reach, I would consider RO for kitchen usage, but anything beyond that would surely be cost prohibitive. I had to use RO water in the greenhouse in college at A&M because the city water was higher in sodium. The other big issue is what to do with all the brine.

 

[Valveman]

There isn't room inside 4" casing for the 3" pipe couplings. You would have to use straight wall 3" casing. Even then I am afraid any type of screen will just clog and not let the pump have water.

You might have to call TCEQ for help. However, since congress gave them power to enforce rules, all they want to do is enforce rules. TCEQ is not there to help as they should be. They only want to enforce antiquated rules and give out fines. Although, you might find someone who could at least find a well log for you. Maybe??

 

[TJanak]

Forgot about the couplings, and I see your point on the clogging. I was thinking that may be an issue.

I've got a good hypothetical question for you:

30' from this salty well we just drilled is a 4" PVC well that was being used for a house that used to be here (house destroyed in hurricane). During hurricane Harvey there was 2' of storm surge over this area. After the storm the local well drillers came out and jetted the three existing wells on the property in that time (2017) before I bought the place. Two of the three had a bunch of junk in them as you can imagine, but cleared up and work fine. This third well (the one 30' from where I just drilled) they jetted and said it never made over 5 GPM. The previous owner said it was like the rest of the wells before the storm and made 30+ GPM. I've wondered for the last two years what would have happened down there that would change things so much.

Also wondered how much sea water could have gone down there in the 2-3 hours it was under water, and if I'm still pumping that up 2.5 years later?

Been running my new well again non-stop for the last 24 hours. Wonder if I should run it for a few days and test again?

 

[Valveman]

A lot of sea water could have gone down the well in that length of time. It will spread out and get diluted with fresh water, so there will be much more needed to pump out than went in. As an example, once I had a customer with hot water coming out the cold water faucets. Turns out there was a hole in the pipe above the pump and water circulated in the well until it got really hot. After fixing the hole in the pipe, this well pumped hot water for several more weeks. Aquifers hold a lot of water. When it gets salty or hot, you have to pump a lot to get the well cleaned up again.

 

[TJanak]

Ran the 60' well with 5 GPM choke for 24 hours into a white 50 gal drum to try and gauge sand output. Kind of hard to see but this is what accumulated. Maybe 1/4 cup at the most?

I'm thinking a two cistern setup would be ideal if I could get an output from the first cistern a couple foot from the bottom to allow settling before gravity flow into the second cistern.

Sending off a sample again today to check on salts, etc. I get a taste that seems more like iron than sulfur to me. Water also had this yellowish tint in the drum. Thought maybe iron but could just be light coming through the drum, etc.

Cary, found the state well reports for this 60' well and they used 0.014" screen in 1990. All of the new wells drilled now (including my new one) are installed with 0.006" screen. I'm assuming this is why I'm getting the fine sand. For some reason this well driller back in the 80's and 90's used all 0.012" and 0.014" screen, and they often pumped sand.

 

[Valveman]

.014 is still pretty small. With enough pumping you maybe able to clear up all or most of the sand.

 

[TJanak]

Forgot to mention, it pumps visibly dirty water running straight out of the 1.25" without the choke. Think I'd be better off pumping it hard without the choke? At what point will it ruin the pump?

 

[Valveman]

As long as it doesn't pump the well dry I would let it run straight out and try to pump out as much dirt as possible. Sand is not good for a pump, but I have seen them pump a pickup bed full of sand and still work fine. Even if you sacrifice a pump, having a clean well is worth it.

 

[Reach4]

Lakos SUB-K might be good for you. A longer-tailed flow inducer sleeve is a cheaper alternative.

Lacos Sandmaster should get sand after is it pumped up, but before your pressure tank.

https://www.lakos.com/homeowners/

 

[Catherine S]

Two related questions here really. Building a house currently and had a new 4" PVC well drilled. Knew it was a gamble as to water quality and results of test are attached. I plan to retest just to be sure. Don't have the report yet from the driller but 165' deep, 1 HP pump. This thing is salty, high sodium. Boron high too, with more chloride and bicarbonates than ideal as well. Funny thing is my plumber asked how I'm going to filter the water to clean it up. Not sure why he doesn't know you can't filter out sodium, chloride, etc. RO is the only option and that won't work for irrigation! I'm considering not using this well because I'm not sure how to effectively use it. We are big landscapers, gardeners, fruit growers, and this water is effectively useless. $7500 down the drain.
View attachment 61569
About 500' from the house is a 4" PVC well of unknown age that was used for cow water. 60' deep. 1/2 HP 2 wire pump set at 50' or 55', can't remember. It has a 5 GPM choke on it. When i pull the choke out it makes plenty of water, but pumps sand. Put the choke back in, no sand. The water quality from this well is much better. I am seriously considering using it for the house, but have to deal with the sand issue. Sure I can pump into holding tanks at 5 GPM, but would need a lot of storage for lawn and garden irrigation.

Do I have any options for lining this well to screen out the sand? What would be the best route to proceed from here on making this well useable?

Thanks,
Travis

Might look at capturing roof runoff and treating for household use. There are some Ag crops that can grow with higher salinity water, but ground saturation can be an issue in West Texas where there is not enough rainfall to leach it. For treatment need to install filtration system with UV.

To evaluate rainfall System and storage size, do a daily water balance with rainfall records from the past 5-10 years (available through NOAA).

 

[Reach4]

Might look at capturing roof runoff and treating for household use. There are some Ag crops that can grow with higher salinity water, but ground saturation can be an issue in West Texas where there is not enough rainfall to leach it. For treatment need to install filtration system with UV.

To evaluate rainfall System and storage size, do a daily water balance with rainfall records from the past 5-10 years (available through NOAA).

I would not use UV for the irrigation water. You probably were thinking of drinking.

But collecting rain from rain gutters in the Corpus Christi area sounds like a good way to get salt-free water. Pumping that to trees for drip irrigation sounds productive.

 

[TJanak]

Reach, forgot about the Lakos. Thanks for the reminder, those are viable options. I need to pull the pump and measure depth to bottom and depth to pump set. I'm thinking the pump was set around 55 feet since the well is screened from 51'-61'. How close is too close to the bottom? I'm not sure if the bottom is open or capped.

Think I will pump the well hard without the choke and see. Gotta drag the generator back out and hope it doesn't catch the pasture on fire overnight.

I'm considering rainwater storage, I've got plenty of roof. Didn't see myself in this predicament here after growing up 60 miles away in the land of nearly unlimited high quality water.

 

[TJanak]

Update to my water well situation:

Local driller (not the one I used but probably should have) would put a 2" screen (0.008") in my existing 4' casing 60' well (0.014" screen) with good quality water and try to clean up the sand that way. I asked about gravel pack between the 2" and 4" casing and he said he can but would be close to price for a new 60' well. After much consideration decided to move close to the new house and have him drill a new 4" well (0.008" screen) to hit this same 50'-60' depth sand with better quality water than my 165' deep salty well. Just talked to him and ended up around 62' total depth with 20' of sand and screen, properly gravel packed, and jetted about 20 gpm. I'm thrilled, just need to get a pump in it. Static looks about 10', don't know pumping level.

I can have him put in a new pump and tank for $1600 or use one of the existing pumps I have:

Option 1 is a Pentair Myers 2S52-10-P4-01 which is a 2 wire 1/2 hp 10 gpm in my 60' sandy well. (Not sure how much sand it has pumped over it's life).
Option 2 is an almost new Goulds 10GS10 in my 165' salty well. Not sure on motor except 1 HP.
Option 3: Buy a different pump and put in myself?

Opinions? Driller is concerned the 10GS10 may cavitate at that depth if run unrestricted.

 

[Valveman]

With a static water level of 10' you don't want to run even the 1/2HP pump wide open. Pumping more than about 16 GPM with any 10 GPM pump will cause upthrust, not cavitation, but still not good. Just put a 15 GPM Dole valve on it and you can run either pump in the new well. You can also just use a ball valve and set the flow to 15 GPM max.

A 1/2HP needs about 80' of head or 35 PSI minimum on it to keep from upthrusting. A 1HP needs a minimum of 160' or 70 PSI to work properly. When using a pressure tank/pressure switch at 40/60, the 40 PSI minimum is the same as 92' of head. So, the 1/2HP would not need the Dole valve when running a pressure tank or sprinklers at 40 PSI. But the 1HP would still need the Dole valve from such a shallow well.

 

[Reach4]

Not #2. I am not a pro.
If you put in the pump yourself, I would go with SIDR polyethylene. If the pump guy does it, expect 1 inch or 1-1/4 inch pvc.

 

[TJanak]

Gotcha, thanks. Was going to ask for an explanation on upthrust but Google returned a thread between Cary and Reach from 2014 that explained it perfectly! I think I mistakenly told the driller the 165' well pump was 20 GPM, probably why he was concerned with cavitation. I had to go look up the model.

So sounds like I'm best off with the 1/2 HP. Any drawbacks to using a 2 wire pump? I've always used 3 wire.

The 1/2 HP currently has 1" poly on it. Any reason to upsize to 1 1/4"?

I guess according to the chart below the 1/2 HP will top out around 12-13 gpm?

 

[Reach4]

I guess according to the chart below the 1/2 HP will top out around 12-13 gpm?

Most houses, not doing much irrigation or filling pools, are fine with 7 gpm.

One other thing: 10 gpm pumps usually have 1-1/4 inch output. You can adapt.

Will your water be coming from below the pump or above? If above, I would not want a 1 hp motor generating heat, unless you can put on a flow inducer.

2-wire is very common and good for 1/2 and 3/4 HP. If your electricity was very expensive or if you wanted to run off of a smaller generator, there would be some advantage to 3-wire-- less starting current in the first few seconds. Also, there have been some posts suggesting that Grundfos 2-wire may be less reliable than 3.