Did I get screwed?

Started by FrankInWI, October 01, 2010, 11:10:00 AM

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FrankInWI

Upgraded from a shallow point well (10') to a deeper well last week.  I really trusted the guy who put it in...but now I have some reservations about what he did...and what the other guy who put in the pump and hooked it up did (next message).  

Most of the houses in my area have wells in the 90' range.  One has a very deep well, 350', it seems like he got ripped off.  

My well came in at 58".   He used his smaller rig to put it in.  He pounded 3 20' long  6" steel casing into the ground and kept checking the water/substrate with a big tube with a check valve he would lower into the well.  

When he bid the job, he estimated it at 100' (I would pay less if it came in shallower) and said I may or may not need a "screen" which would cost $1,000 if I did need it, based on his assessment.  

He started getting more water somewhere over 40'.... Much fine sand.  He kept going deeper till mix of sand/fine gravel.  He went deeper to be in better sand/gravel.   He had a cool looking set of brass trays stuck together to measure the fine-ness of the sand/gravel.  The substrate was held back at various levels of screen and a small amount went to the lower very fine screen.  

He determined by that what grade of screen he needed (a number 12 I think).  That went down the casing then.... And he pulled the casing UP so that the screen would be exposed below the casing.  

Driller said flow about 30 gpm.  But he rated it on the paper to the state as 15 and marked it as that under the well cap.  Said he did it so state wouldn't ask for higher rate permit (commercial vs. residential flow).  Later.... The pump installer brought a 15 gpm pump with him..... but at 110v.  I wanted 220... which he said he goofed at and left at shop.  Had his installer run back and get the 220v one.... Which ended up being 12 gpm.  He said that is rated at 150' deep well, and at shallower it will pump much more.         Total cost about $5,400

QUESTION # 1 -  Did he stop drilling early (60 vs. 90) and got a well with more sand cause he didn't go deeper into more gravel content?  .... And the screen let him do this? (and the $1000 price still got him profit vs. charging for more drilling).

QUESTION # 2 -  What's with needing 15gpm at one point... but a 12 gpm is just fine at a later time?
god helps those who help them selves

glenn kangiser

In my opinion, you can go back to trusting him, Frank.  I think you got a good deal.  The driller did not try to pass up a good water producing stratum just because you were primed up and ready to pay more.

The classification screens are only used by a professional who knows what he is doing.  A fly by nighter would have just dropped in a generic screen and taken his chances.

The driller has no idea of exactly where the water producing strata are exactly until he goes there.  I don't care if there is a well ten feet from it and you have a well log... the new well can be significantly different....even in ten feet.  Imagine a cliff of clay or other soil along the river - drilling ten feet from the edge you would encounter many layers of soil but if the river filled in next to the cliff and centuries later you drilled in the fill it would be totally different than the area on the firm ground.  That has happened to the earth in all valleys as streams wander back and forth and floods or glaciers fill the valleys with sediment.

Where the underground sand fill is, is the area that produces your water.  Through use of the classifier screens the driller will assess the sand outside the screen then size the screen to allow the small sand to come through but the larger sand to be trapped behind creating you a natural filter pack which after development (via air lift or over pumping) will then graduate out to stop the small sand from coming into your well.

Going deeper into a large sand stratum would not gain you anything - since it is sand, the water will be pretty much the same from top to bottom - there is no separator.  Drilling through lots of sand creates more and more pressure against the casing in some instances -depends on soil conditions- possibly he thought production was more than adequate and there was no need to go deeper risking problems with the casing pull back and the quality of sand for the screen was good.  

Drilling farther could put you into an area with no water (all clay for 200 feet or more as the 350 foot deep well may have hit)  or fine sand without enough coarse sand that would not make a good filter pack.  Lots of variables.  A good driller will not pass a good stratum unless directed to by the owner - then it is the owners responsibility for the added cost and possibly a well way deeper than he wanted to pay for due to conditions.  

Was it a cable tool rig or rotary, just for my curiosity?

The screen let him stop in a good filter material rather than pass it looking for a clay bottom to stop the casing in - then drilling an open bottom well -- not likely common back there, but very common in California.

It is common to put down less flow on an estimated flow for liability reasons.  Most estimates are an educated guess although a weir on the developing water could give a pretty accurate estimate.  If you write 15 nobody will be able to squeal if it is 26 rather than 30 gpm, besides any other benefit with the state.

Not needing ------15 gpm or 12 gpm - it is the range of the pump.  There is a curve that tapers off as the pump level gets deeper.  It all depends on the pump model, horsepower, impellers etc-- and where the curve of the 110v model put it and heavier load and more water per minute in it's range.  A 220v pump would likely be rated to pump from deeper bringing less water but with a bit more or even the same horsepower. More impellers will restrict the flow a bit but give more lifting pressure (head).  720 gph is still a lot of water.  I get only 60 gph on my well.

Both pumps will use about the same amount of watts to pump the same amount of water but the 220 can use smaller wire for the same horsepower.

Hope this helps to understand what is going on here.  In my opinion he was treating you fair.  Feel free to ask more questions.  I am still a licensed driller but only consult and do the occasional pump now.   I recently advised on a well in Africa.

A driller here tried to charge one of my customers $19,700 just for the pump, tank and 320 watts of solar panels.  She was going to cut my portion of the job down on a cabin due to his overcharges against a limited amount of project money, so I did the pump and solar for half price and still made a decent profit.  I don't know what he charged her for the well.  Her pump was 2-3 gpm Grundfos SQ Flex solar - but not that much more expensive than a regular system.



"Always work from the general to the specific." J. Raabe

Glenn's Underground Cabin  http://countryplans.com/smf/index.php?topic=151.0

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FrankInWI

#2
Glenn.... I kind of hoped you'd answer... and boy did you.   VERY much appreciated.  Thanks!  8)

I'll try to get a pic of the rig posted... but it was cable going over pullies attached to a very long bar/pipe with a cutting head on the end.  

He'd put the bar in the casing and have it pumping up and down a stroke at a time...... then he'd drive the casing itself deeper by pounding the casing on the top end (with a boot on).   I probably described this horribly.  

QUESTION #3 please?  The pump installer dug down and put the pit adapter on the pipe/casing.  He cut a rectangle about 6' down from the surface... installed the pit adaptor, and welded it on... on all four sides.  It was tough for him to do it... I have very high ground water and he was leaning from the bucket of the machine he used for trenching (aka backhoe type duhigy).

The water was being kept low in the casing (to keep it temporarily below the pit adaptor hole) by him having a temporary pump in there pumping water out of it onto another area on the surface.   He struggle a bit with the welder.... changing rod type, adjusting current, etc.  WHEN he was done he quickly dumped in the sand to fill the hole to a level well above the adaptor.  He said "we'll fill it in right away to prevent caving.  He didn't do the same on the wide deep 5' deep trench all the way to the building.  

THE QUESTION: I think he covered quickly because when he would turn the pump off the water would rise pass the adapter and I bet it leaks like a sieve.  Is that supposed to be a tight seal.... or is leaking from the joint between the adaptor and the casing no big deal?
god helps those who help them selves

rdzone

I would think it is a big problem if ground/surface water can leak into the casing...This could lead to contamination of your well, but I am not a professional.  Hopefully Glenn will chime in.
Chuck

archimedes

All the pitless adapters I've seen were threaded and had a rubber gasget to seal them.  I wouldn't want surface runoff getting into the well.  But wait for Glen's response.
Give me a place to stand and a lever long enough,  and I will move the world.


glenn kangiser

#5
True - the surface water should not be able to get into the well.  There should be a tight seal around it keeping the water out.

Did the well driller leave the casing in the well after pulling it up part way - I assume he did and only pulled it back enough to expose the screen.  If he left the solid steel casing in the well bore to near the screen that should pretty well stop and surface contamination from getting in from the outside.  The casing will seal pretty well or if not bentonite can be poured around the top to assure a tight surface water seal.  20' is the law around here.  Did he also put in a conductor pipe - a larger pipe around the casing?   I did that and welded it to the casing solid to make a tight seal 20 feet down - 20' conductor set into the undisturbed soil at the bottom of it then the smaller casing continuing from bottom to top and a bit above the conductor.

I did not use pit-less adapters here as there is not a frost depth but am familiar with them from water well drilling studies for license and other research.  Considering that he had to put the adapter to the casing I will assume that there was not a conductor, and in fact most drillers here did not use them due to the added expense, but I figured it was worth it for the ease of sealing as well as getting a good start with no surface friction on the casing.

You are saying that your standing water level is above the top and you suspect it is leaking into the inside of the well?  We may need to know more.  Most well seals have an extra hole in them that you can look through to see what is going on.

If the water level in the well is so high that it is pushing up from the inside of the well to the outside - artesianing, then it is not as much of a problem as the pressure is positive and keeping contaminants pushed back by its reverse pressure, but there still should be no connection in case you pull it down inside pumping and reverse the flow.

Possibly cleaning out around it and sealing it with hydraulic cement could take care of the problem.  You may need to run the pump to pull it down to stop flow although hydraulic cement will set under water.   Likely the welding problems were caused by water getting into the weld area - very hard to nearly impossible to weld good in that case.

That is a cable tool rig.  I still own three of them - they are at our place in the valley.
"Always work from the general to the specific." J. Raabe

Glenn's Underground Cabin  http://countryplans.com/smf/index.php?topic=151.0

Please put your area in your sig line so we can assist with location specific answers.

glenn kangiser

Sounds like your casing extends to the top so maybe there is a cap over it you can pull and look down in the well using a strong light or a mirror reflecting sunlight into the well.  Sounds like your static level may be above the pit-less adapter - just a few feet under the cap?
"Always work from the general to the specific." J. Raabe

Glenn's Underground Cabin  http://countryplans.com/smf/index.php?topic=151.0

Please put your area in your sig line so we can assist with location specific answers.

glenn kangiser

Going back over your post - if the water in the well  when you are pumping is always higher than the surface water ie: you can't pull it below the pit-less adapter,  then it is no big deal - but ideally there should be no communication and the concrete - or even a bag of bentonite pellets well placed around the leakage area should seal it well.

Bentonite pellets are available through a pump supply - or well driller supply.  Your driller should be able to get them.  Looks like pelletized rabbit food but swells to about 10 times it's own size making a sticky greasy mess that will stop cross contamination.  You can pour it into a hole around the adapter even if there is water in it and it will expand and seal.

I'm kind of guessing as to the problem and solution here as I am not 100% sure if I am picturing your problem right.

The thingy on the top of the casing as he drove it was called the casing head.  It does tend to cause sand to get tighter around the casing when driving unless the formation is loose.  All of my rigs were fitted with hydraulic pull down cylinders with the big rig having over 100,000 lbs of pull.  Pulling the casing into the ground using anchors if necessary helps greatly but I think our conditions here were tougher than back there having hard clay most of the way with occasional sand strata and average was 80 to 200 feet to water.

Most wells I drilled were 250 to 300 feet deep but a few went to 700 or more.  I cleaned one out to 1550 one time with the big rig - it even had a bit of oil in it - a couple did and a couple had gas in them.  one would throw a 3 foot dia flame about 15 feet.  Luckily it only produced gas while pumping it.  I had a geologist running developer and he had worked oil and gas wells.  He lit 'er up.

I drilled and repaired, or supervised around 300 wells over about a 10 year period when actively drilling.
"Always work from the general to the specific." J. Raabe

Glenn's Underground Cabin  http://countryplans.com/smf/index.php?topic=151.0

Please put your area in your sig line so we can assist with location specific answers.

Paulklondike

Hello Folks newbie here
I live 100% off grid.
I was finaly able to get a well drilled, but the driller and I butted heads....him saying he was coming and then not showing up mutiple times. Never called to say he wasnt showing up.Then one day I wasnt home and he went ahead and drilled well. 60 ft....limestone.  Im 1500ft from a large lake. Neighbour beside me has 60ft well....other neighbour has a 17 ft blasted 2 acre pond. So tons of water around....when i got home he was packing up and said it was dry well....he spent exactly 3hrs 20 mins drilling well. There was alot of bentonite laying around....i put flaslight down to bottom of well....it was dry. The casing is sitting flat on rock. I filled the well with city water to see how long it would take to drain and what level it would be at.
It hasnt drop by more than a ft in 2 days. 58 ft of water. So did the driller line the entire bore hole with bentonite on the outside of casing...or is it because 6 inch casing is sitting flat on limestone? Any ideas or insights?.im thinking about jacking casing up about 6 inches and then chorinating well to break down bentonite, flush multiple times.....is this a good course of action? Insight comments welcome.
Thanks