I'm in Standing Column Well Hell - need help

Discussion in 'Standing Column Well (SCW)' started by geochallenged, Mar 26, 2013.

  1. geochallenged

    geochallenged New Member

    I purchased a home in Raleigh NC that has a 500' SCW that produces 25gpm and is used to supply household water and supports two 6 year old FHP geothermal units (5 ton ES-61 and 2 ton ES-24). The 5 ton unit is zoned to support a basement on one zone and the second zone on the main level. The 2 ton unit serves a small upstairs in a single zone.

    The system has two large bladder tanks and a Lakos TwistIIClean spindown filter on the geothermal input post bladder tank (that I installed to replace a standard spin down filter that was shot).

    The well is producing fine sediment that causes the filter to have to be flushed frequently (every 3 days) or the system loses pressure and craps out. Additionally this winter it has had freeze ups that can't be explained by sediment but that require that I put the system to A/C mode to unthaw the coils. I have had several different people look at the system and continually get conflicting information on how to fix the problem and have spent a bundle trying the things that were recommended to no avail.

    When I purchased the property the pump was located at 300' and the return line was above the surface of the static water line. The first attempt to fix the issue involved adding a sleeve to the pump and putting the return line down 20 feet below the static water line. This helped but did not fix the issue (filter could go for 7 days without being purged).

    The second attempt involved putting a camera down the well to see what was happening and they noted there was a strong water vein at 80 feet below the surface that they felt was contributing to the washing of the well. They recommended putting a plug into the well to separate that portion of the well but the geothermal contractor said that would ruin the performance of the well. They then suggested that we try moving the pump up to 160' and moving the return line to the bottom of the well with a u-bend on it to force the return water upward. They did that and removed the sleeve on the pump at the same time. This did not help.

    I have been looking at the LAKOS Sandmaster H20-20 with Accupurge as a possible solution to my sediment problems because going to Closed Loop costs so much more money that I can't afford right now.

    A few questions:

    1. Any other ideas for how to fix this issue?
    2. Would taking my household well off of this system help?
    3. Any experience with the LAKOS Sandmaster as a solution?
    4. Does anyone know what size particles I need to filter out to keep from injuring the Geothermal systems?

    Any help you could provide this Geochallenged Girl would be appreciated!
  2. waterpirate

    waterpirate Well-Known Member Industry Professional Forum Leader

    What does the local driller say? It has been my experiance that filtering the amount of water needed to run a geo system is a fools errand. Has anyone talked about a rehab of the well via overpumping or a surge block? Trying to cure the supply not treat the distribution is allways the first choice. Any chance the reintroduction of the water into the well is causeing turbulence? How about changing over to a pump and dump if leagal in your area to evacuate the silts, not continue to reuse them till they plugg your filter?
  3. geochallenged

    geochallenged New Member

    Thanks for your reply Eric. Well rehab has been addressed - see below. Never heard of a surge block. As for pump and dump I would be concerned that the water level of the well would drop too much to be viable given I use it for household use as well plus I don't think that will address the issues found regarding strong water veins washing the well walls.

    If I could find Dr. House for SCW's I would gladly use him because right now I feel like I am in a trial and error experiment when I need a system engineer/diagnostic expert.

    I've had two geothermal HVAC contractors (who both have different opinions - return on top, return on bottom for example), a well specialist who is a geologist (who did the camera down the well) and a Well company (who has been pulling the pump, resetting it to new locations within the well and adding/removing return lines during each experiment) looking at this for over 6 months. The well specialist suggested two options based on the camera investigation, both of which would make the well not viable for geothermal according to the HVAC team - they were 1)adding a Lansas Inflatable Packer at the area where there is a strong water vein coming in near the top of the well, and vacuuming out the well to remove existing sediment or 2) adding a 4" PVC sleeve down the entire well (500') and also vacuuming. Option 1 means that the return line can't go back into the well. Option 2 means not enough heat transfer. I also am unsure if the household water usage is contributing to this strong vein of water washing the walls of the well when the water level drops below that vein during heavy household usage.

    Lakos tells me that the Sandmaster filter is used for this type of application all the time and yet I can't find any info on real case studies or found someone who has used it successfully. Hopefully someone here has some experience with that filter.

    The whole thing has been keeping me up at night for 6 months and I don't feel any closer to solving it. I'd like to fix this if possible without considering closed loop but I'm really getting the feeling that this is all just trial and error and may not be able to be fixed.

    Any ideas on what size particle I need to filter down to?
  4. Calladrilling

    Calladrilling Member Industry Professional Forum Leader

    The short answer is yes, I do have experience with the Lakos sand master system with the auto purge valves. They work great for a long period of time until the auto purge gets clogged with sand or worn down from constant sand flowing through it.

    The true issue though is with your well producing sand to begin with. Like mentioned above, has it been redeveloped yet, or just tinkered with to try to mask the sand issue? I would lean towards fixing the problem at the source before spending the money on the Lakos filter because they are not cheap either. You are fooling with your supply of domestic water not only your geothermal heat pump water. I would talk to local driller about your options of reducing the sand from coming into the well. When your heat pump runs it pumps sandy water from the well then dumps sandy water right back into the same well, at the same time it's bringing in new sandy water every time the pump runs for domestic water too.

    Does that make sense or did I just make the waters a little more unclear?
  5. geochallenged

    geochallenged New Member

    Hi Dan,

    When you say the Lakos Sandmaster works for a long time what does that equate to? Months? Years?

    The only two solutions offered by the well rehab expert will not allow the well to support the geothermal because it will kill the heat transfer mechanism if I run a PVC sleeve all the way down the well or if I put an inflatable packer in to section the well it won't allow for the return of the water as the packer gets grouted above it to the surface. I don't know of any other options. As a driller, can you point me in any other direction?

    The waters are definitely still cloudy on this one.
  6. Calladrilling

    Calladrilling Member Industry Professional Forum Leader

    I they can not redevelop the well and flush the sand out, I think its time to roll in the drilling rig and go with either a new SCW or closed loop. The Lakos filter is nothing more than a bandaid to a bigger problem. They worked in places where I have used them from months to years in some cases. It all depends on the size and amount of sand your well is producing.
  7. geochallenged

    geochallenged New Member

    Can you describe what is involved in redeveloping the well? Unfortunately I can't afford the solutions of abandoning the existing system and moving to closed loop or drilling a new SCW. This is a 6 year old system! The down hole camera report said the following:

    "Rock borehole walls inside this well are shedding sediment and causing the water quality problems. During times of heavy water usage the well goes into cascade and releases sediment from the borehole walls because of physical and chemical abrasion. When the water level is lowered, this well begins to cascade. Abrasive physical forces are created at the well water level interface during cascade. When the pump is turned off and the water level begins to rise the interface forces are increased. Information from the data tag attached to this well lists the total depth as 500’ and yield as 20 GPM. The pump is set at about 300’deep. With 200’ of space below the pump and up-flow from deep veins, sand and grit are not flushing from this well but accumulating to a maximum level and clogging the filters. Geothermal water returned to the well is creating its own addition to the filter clogging problem. Warm water is cascading back down into the well and bringing air gasses back down into the borehole. A slight slime bacteria growth is generating a powdery look inside the borehole. This growth is not out of control and the constant return of gallons of water to the well from the geothermal unit is helping to flush microbial growth and prevent excessive accumulation of slime inside the well. However, excessive air gasses are acting to soften and release sand and rock grit from the borehole walls. With the pump placement and dynamics that have hydraulic control of the flow; this well has accumulated a river of sand and grit. Fine sediment seems to originate at the top and fall to the bottom and continuously be reenergized back upward from the deep water veins forcefully flowing up to the pump as the pump cycles on and off to meet its demands. "

    If the Sandmaster can help me for a few years until I can afford the big jump to a closed loop system I would be happy. Also, I would like to know what size particles should I be filtering to for my FHP systems (ES-61 and ES-24) that are running on this system. FHP won't give me that info. Maybe a lower mesh filter could be used to help alleviate some of the problem?

  8. Calladrilling

    Calladrilling Member Industry Professional Forum Leader

    It's your decision to try to filter out the sand. It's a project that comes with a price tag that will have to be justified by you too. The Lakos sand master works on every job we installed it on, but the brass valves Will always clog and become worm out over time. How long it lasts will depend on how much sand and how much it needs to be flushed clean.
    I would leave your TwistIIclean inline after the Lakos for added insurance with maybe least 100 mesh screen. I would prefer to have the least amount of sand as possible to enter my heatpump.
    Best of luck.
  9. waterpirate

    waterpirate Well-Known Member Industry Professional Forum Leader

    Not the best solution, but you may want to focus on filtering the domestic supply only and seeing if the sediment will travel through the HX without clogging it. Another option would be to periodicaly bleed the super sandy water out of the well. A sort of flush if you will. The report you posted did not look promiseing as it poses a condition of the upper rock your well was constructed in is causeing the problem. The fact that they want to sleeve it to cure the problem indicates to me that this condition is not uncommon in your area, or someone would have suggested a re-drill by now.
  10. AMI Contracting

    AMI Contracting A nice Van Morrison song Industry Professional Forum Leader

    This would indicate inadequate GPM which yes is likely the sediment/filter. Freezing the coax can be just as dangerous than running gritty water through coax.

    Why not try pump and dump for a few weeks on few weeks off and see if it will minimize grit content?
  11. geochallenged

    geochallenged New Member

    Thanks Dan. I really appreciate the help. Lakos says the Sandmaster should be installed between the pump and the bladder tanks. Do I need to put something inline to protect the system should I need to replace the brass valve at some point or if it fails? If I can get this solution to work for a couple of years until I can save the $ to do another type of system I will be happy. I already spent about $10K trying to diagnose the problem ..........$1K for the filter if it works seems like a good next step until I can find another solution that I can afford. Had I known about this problem I surely would not have bought this house or I would have asked for a hefty discount on the price to fix it. Unfortunately the inspectors didn't find it either. It is a shame that this type of technology gets a bad name from the fact that unskilled people are working on it IMHO. Thanks again for your help!
  12. Calladrilling

    Calladrilling Member Industry Professional Forum Leader

    Home inspectors kill sales in my area all the time due to lack of knowledge about wells. They throw their opinions in all the time when they shouldn't open their mouths about wells and water treatment when they know Nothing about them. It's just the nature of the beast I guess. We offer well inspections above and beyond home inspections , for customers in the know.
  13. AMI Contracting

    AMI Contracting A nice Van Morrison song Industry Professional Forum Leader

    Warning: Joe's about to embark on another tirade......
    Preface: I have met some very good and knowledgeable home inspectors. That said......

    Home inspector knowledge varies wildly. The problem is if consumers had the knowledge to detect one that was full of $#!+, they wouldn't need to employ one.

    After several occasions where I was called in to correct imaginary concerns of home inspectors, I decided to put together a team of real inspectors- you know state licensed municipal inspectors (like myself) each with their own specialty (plumbing, building, etc.).
    The first obstacle was insurance. Errors and Omissions insurance was available to "certified" inspectors (those who took 1 week and a $500 on-line course to become expert in all things home related) not state licensed municipal inspectors (with 25 years in the trades and 15 in inspecting).
    The second was the real-estate agents. They don't care whether an inspector is right or wrong they just want to negotiate a sale price.
    The third was the sellers- why pay someone to be correct when they can simply offer an allowance for percieved problems and finally sell this thing.

    I came to the conclusion that the home inspector industry is genius. As buyers advocates they negotiate discounts on properties for a fee.
    Remember when our parents told us to always offer 10% less than asking price? These guys tell their customers to go ahead and offer asking price but ask for 10% in repair allowances......
    in other words they get paid for saving money that was never on the table.......genius!

    When I married my wife, we sold her home and she and the agent conspired to keep me un involved in the transaction when I went off about the buyer's "inspector" and his imaginary required improvements. They were comfortable with the adjusted price offered. I was not permitted to screw-up the deal with facts....

    My advice when asked, if you have a concern about something specific in a home you are about to purchase, hire a professional in that area. Take the $500 you are going to pay a home inspector and buy a real-estate warranty. The warranty won't cover everything but the inspector won't cover anything.

    Ok, done.

    My advice to the OP again. Why not go open loop for a week or so and see if the water quality improves. Has a well pro suggested you need to worry about your well capacity if you don't return the water? Or is this simply a concern you have without further investigation?
  14. geochallenged

    geochallenged New Member

    That is a good suggestion. I will try it. I am afraid that because there is so much water coming out of the well that if I pump and dump I won't have enough water (e.g. the pump is too high up in the well and the water line will drop from the usage but I dont know how to test that theory?) but I don't know enough about wells to know if that is a rational fear.........They do have a faucet on the return line so I could try that. Any thoughts on what to look for other than no water in the house or the systems shut down from no water?
  15. AMI Contracting

    AMI Contracting A nice Van Morrison song Industry Professional Forum Leader

    Don't speculate about your wells capacity, ask one of the pros you have already paid.
  16. geochallenged

    geochallenged New Member

    I'm sure part of it is the fear of running out of water especially since my household water is on the same well.

    The well is producing 20gpm according to one of the well guys and it says that on the pump tag. He timed the off on of the pressure switch at the bladder tanks to determine that. Not sure if that is accurate or not.

    With the 2 units I think I need about 18gpm to run them. The spec from FHP says 5-7gpm for the 2 ton unit (ES024) and 5-7gpm for the first step of the ES-61 and 7-14gpm for full capacity. Does that mean that I can run these at the lower bound and still be okay. Not sure how that range works. Do I calculate some kind of duty cycle and add in the estimated household usage to determine that?

    As for the home inspector. I hired and paid for 3 inspections since I had never owned a home with a well or with geothermal. I had not only a general home inspector but a well/septic inspector and an HVAC inspector. None of which reported anything about the system configuration (standing column), none bothered to lift the toilet tank lid to see the dirt in there, and the well inspector didn't even report that this was a reinjection well (he didn't even know it when I finally found out and went back to him). I'm sickened by the whole thing and just want to get it fixed of at least manageable.

    In terms of running the well to flush it, do I open the faucet at the well head and let it run or do I do something else? Should I turn on as much water as I can in the house?
    For how long?
  17. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    As Joe said, the home inspection thing as I see it is a sham. I too looked into it and found liability insurance impossible to get. To be an industry standard home inspector you do not need fear and common sense, just the ability to send out a bill for the inspection. I am sure that there are reputable home inspectors out there, but I have yet to meet him/her.

    Water is THE universal solvent.

    It will pick up and move anything on this Earth given the time to do so. Therefore I do not like to let it run wild. I like it in a closed system where I can kill the growy things and treat it to inert. I am just on the way home from a road trip, where un-treated "city water" had grown big rust colored globs of snot some thing that plugged a co-ax heat ex changer. I shudder to think what happens when one takes the water through a heat pump and back out to one's drinking water. What I learned this week makes me vow to never ever not treat a geothermal water side again.

    I feel your pain, but I do not like and never will install a non-closed loop geo system ever.

    You need a good knowledgeable geo contractor. He will have a good well person in his tool bag.

    None of us know all of everything which is why we type here and share information with the general public and each other.

    I am not a well guy so I can not tell you what to do except with my essay. Joe types bold when he rants. I do not.

    Keep typing and we will keep trying to help your cause/system...

  18. geochallenged

    geochallenged New Member

    I've been considering drilling a new well for household water because of just the factors you mention above. I don't drink the water but I do shower in it. When I bought the house I had no idea that the geothermal was running off of that well that was providing my potable water. I would have hoped that one of the inspectors would have educated me. I don't think they knew it either. Scary but as you mentioned, as expected. As a single female this purchase was a big deal for me and that is why I forked out the extra money for the multiple inspections thinking I would be covered. Unfortunately now I'm finding that the people who are in this business in this area don't even understand it if it falls outside of "textbook installation". I've learned more about SCWs then they know. SCWs aren't the norm here and I think the guy who installed it likely took this route as a cheapest way to get geothermal. I too think this configuration is not suited for this geology. That said, I'm stuck with it until I can afford to switch it out or it craps out from the sediment. Until then, I think the Lakos Sandmaster is gonna be my new best friend. I'm calling it "let's fix the well experiment #5". I'll let you know how it works.

    Thanks again to everyone on this forum. Your experience is invaluable to people like me who are dealing with a problem and trying to brainstorm possible fixes! You guys are AWESOME!
  19. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader


    Sitting in the travel trailer waiting for the coffee maker I thought I should re-read your thread.

    I spent half of last week getting growey stuff out of the house side of a water to water system I designed. I noted a few years ago that buried deep in the small print of the start up punch list that the manufacturer wanted a 20 mesh "Y" strainer installed on the heat pump water side. 48 pages of dos and don'ts, and just a one line mention of the strainer. I thought that odd at the time but started installing them on all my jobs. The attached picture is the strainer showing the growey stuff.

    You can see the mesh is about the size of window screen used for bugs. Coffee is done. I am thinking maybe your filter works too well for your heat pumps. You may not want to shower in sand so I might trade the filter for a "Y" strainer and move the spin off to handle just the house. I am sure that there could be some abrasion to your equipment and I have no clue how long the heat ex-changers will last under those conditions. I do know in hind sight for what you have spent I could have driven down, bought the pipe, subbed out the digging and you would be on a closed loop already.

    I am having a very difficult time wrapping my head around the thinking of your HVAC company. I do not see how re-lining the well in PVC would impact heat transfer. As far as a return line one could drop it and the 4" PVC down the bore before grouting.

    In post #7 there is mention of air adding to the problem, Where is the air coming from? Is the system stile returning to the bottom?

    Do you have enough yard to do a closed loop?

    I will deffer to the well guys on how to best flush the well.


    Attached Files:

  20. geochallenged

    geochallenged New Member

    Thanks for the photo of the screen. The first spin down I had was a 200 mesh, I then went down to a 100 mesh and now am trying a 60 mesh. I called FHP to see what they recommend in terms of filtration but they won't talk to me because I'm not a licensed contractor. I think that the PVC would prevent the advection that occurs as part of the SCW heat transfer mechanism from what I have read. Trust me, I haven't found anyone that can discuss heat transfer mechanism with me with any level of depth out here so I have just read a lot of papers that have been written by people like Carl Orio who has invested much time in SCW design. As for the inflatable packer the well expert insists that the return line can't be put down there with the packer in the well. I would love to hear from someone with some experience with an inflatable packer for a SCW. I'm sure getting a good education! If it wasn't so costly and stressful I might enjoy solving this problem (e.g. if it was someone else's problem!). Thanks again.

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