Electric lake?
Electric lake?
(OP)
This time of the year (when calves are born with double heads and nature in general behaves in an unpredictable manner - we call it "rotmonth" because food can't take the heat and humidity very well). This time of the year, as said, we also hear new and old urban myths. One of them is the electric lake.
This happened: One guy was swimming across a little lake when he felt a tickling in his fingers. It was in a confined area and he could swim out of and into that area. He told other people about it and now it seems that most everyone can feel it - no matter where in the lake they happen to wet their feet. So, I think that most of this is due to a "me too" effect. But the first guy seems to be sure about what he felt.
There are three major pipes terminating in the lake. Two are for snow guns (not in operation during summer) and one is the outlet from a sewer station (yes, very clean). The pipes are said to be stainless steel in the ground and some plastic material in the water.
Questions:
A Anyone had this before?
B What standard measurement techniques are there?
I plan to do a "potential map" using a DMM and a surface electrode shaped as a with cylinder about 1/4 sqm external surface (an ordinary bucket - that is). I will use an iron bar that I just let drop down to the bottom and sink into the mud as a counter-electrode. I will take readings with a high-impedance DMM (it has Gohms on one range) to see if there is anything at all. After checking that, I will switch to a relevant range (all other ranges have 10 Mohms) and then take down the readings across the "offending" part of the lake. I will use a GPS to get my coordinates.
I may also bring some fishing gear.
Comments invited. Especially if you have done anything like this before.
Read all about it on http://www.na.se/artikel.asp?intId=1028536 Sorry only in Swedish. But there is a picture showing a couple of guys trying to "ground" the lake.
This happened: One guy was swimming across a little lake when he felt a tickling in his fingers. It was in a confined area and he could swim out of and into that area. He told other people about it and now it seems that most everyone can feel it - no matter where in the lake they happen to wet their feet. So, I think that most of this is due to a "me too" effect. But the first guy seems to be sure about what he felt.
There are three major pipes terminating in the lake. Two are for snow guns (not in operation during summer) and one is the outlet from a sewer station (yes, very clean). The pipes are said to be stainless steel in the ground and some plastic material in the water.
Questions:
A Anyone had this before?
B What standard measurement techniques are there?
I plan to do a "potential map" using a DMM and a surface electrode shaped as a with cylinder about 1/4 sqm external surface (an ordinary bucket - that is). I will use an iron bar that I just let drop down to the bottom and sink into the mud as a counter-electrode. I will take readings with a high-impedance DMM (it has Gohms on one range) to see if there is anything at all. After checking that, I will switch to a relevant range (all other ranges have 10 Mohms) and then take down the readings across the "offending" part of the lake. I will use a GPS to get my coordinates.
I may also bring some fishing gear.
Comments invited. Especially if you have done anything like this before.
Read all about it on http://www.na.se/artikel.asp?intId=1028536 Sorry only in Swedish. But there is a picture showing a couple of guys trying to "ground" the lake.
Gunnar Englund
www.gke.org





RE: Electric lake?
Standard reference electrode for soil potential measurements is a copper / copper sulphate half cell placed in contact with the earth. It's used for measuring the voltage developed by corrosion cells when ferrous pipework is buried in earth. The cathodic protection companies use dozens of them. Typically we see a few hundred mV on an unprotected pipe and a voltage more negative than -850mV for a cathodically protected pipe
Example: http
----------------------------------
I don't suffer from insanity. I enjoy it...
RE: Electric lake?
Gunnar Englund
www.gke.org
RE: Electric lake?
Or even just hold the ends of the wires in each hand!
Happy hunting.
RE: Electric lake?
RE: Electric lake?
Only experience I have on that front:
I worked my way through college doing pleasure boat repair, as our town has a harbor.
One day I got a panicky call from a fresh water harbor up in the Sacramento delta a 150 miles away. Seems a guest of a a guy on a 50ft Power boat jumped off the back of the boat while it was docked. When he hit the water he was paralyzed due to an extremely strong shock. He essentially lived by virtue of his inertia carrying him to an area of lesser E-field.
Of course once I arrived and investigated it becomes apparent that they had the hot-neutral reversed and the boat's metal was live. Turns out the same problem was occurring locally in the salt water harbor. They never got shocked locally. The reason was that the human body's resistance was great enough that in the marine environment too little current was conducted to be felt. In fresh water it was a whole different story. There the human body resistance was more on par with the water and so shared more of the current.
My bet? You will find 50hz. You will also find one of those pipes are responsible. I'd throw a wired pail in the water a 100ft from the nearest pipe and then probe the pipes,(no boat needed). My guess would go with a snow machine wiring problem.
I like your plan, sink a bucket out form the "detected anomaly" area and then work a grid pattern. You should be able to draw a perfect map with the voltage increasing directly towards one of those pipes.
Be careful as you would be subject to much more of a shock with a remotely positioned ground reference than a swimmer who is only looking at a 6-7foot 'step' potential.
Do keep us posted!!
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com
RE: Electric lake?
Yes. I will keep you informed - if I survive.
Search the local papers if you don't hear from me any more. The headlines will be something like this: "Galen ingenjör dödad av elektricitet i insjö" (Mad Engineer eletrocuted in lake).
Gunnar Englund
www.gke.org
RE: Electric lake?
A.
RE: Electric lake?
But surely. That is one of the problems I wanted to have a view on.
My main question remains: Anyone knows about standarad procedures in cases like this? Are there any?
Gunnar Englund
www.gke.org
RE: Electric lake?
Very interesting post. I especially love the photo of the guys "grounding" the lake.
I believe you will find some very interesting things happening in that lake. You do not mention the depth of the lake and the proximity, if known, between the pipes that terminate in the lake. Maybe some correlation. Is there anyway to check the potential difference between the pipes directly?
It may also be interesting to measure the potential difference across the surface of the lake between 2 boats 50' to 100' apart.
In the US, Mike Holt has done considerable research on stray voltage sources and even attempted to coin a new name for them.
Please keep us posted as to what you discover. And save a few fish for me!
Bigbillnky,C.E.F.....(Chief Electrical Flunky)
RE: Electric lake?
Or could there be some farmer or cottage owner with a pump drawing water for his garden or swimming pool.
Then again is the lake deep enough to be a secret UFO base?
RE: Electric lake?
Gunnar I can't find anything on mapping electrical potentials in a lake. I think you're on your own..
One further comment would be; I bet a metal boat completely screws up any measurements taken from it.
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com
RE: Electric lake?
Did a preliminary test with electrodes. I got around twenty ohms resistance between two buckets at 1 inch distance in water. That indicates less than ten ohms probe resistance. So I know that probing can be done easily and I do not have to think about circuit loading.
I will, as I said, use an iron bar that I drop to the bottom. I will attach "ailerons" to it so it drops vertically and sinks into the mud (no rocks on the bottom of these lakes). I will use the iron bar as a reference and attach an isolated cable (100 metres) to it so I can plot AC voltage level in an area being circa 200 metres in diameter.
I figure that the iron bar will have a much lower resistance to mud than the cable will have to the water. I have measured about 12 kohms (AC 20 V/1.7 mA) between a 100 m cable that was soaked in water for an hour. Resistance remained stable for the last 50 minutes. Even the worst ground rod in moist dirt will give me less than 50 ohms. So I think that I will get 10 - 20 ohms between iron bar and mud/bottom.
I estimate that I will have less than five percent error due to resistance in "ground connection", leakage between cable and water and resistance between probe (bucket) and water. That also includes instrument errors. So the outcome will be valid in that respect.
Gunnar Englund
www.gke.org
RE: Electric lake?
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com
RE: Electric lake?
Gunnar Englund
www.gke.org
RE: Electric lake?
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com
RE: Electric lake?
Mike Halloran
Pembroke Pines, FL, USA
RE: Electric lake?
Mike Halloran
Pembroke Pines, FL, USA
RE: Electric lake?
"This is important RESEARCH, woman! The chores will have to wait!"
RE: Electric lake?
Gunnar, you'll need to calibrate against a non-tingling lake as well. Sounds like a nice career in summertime, boat, volt meter, GPS, a few beers.... like fishing but without the tedium.
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Electric lake?
Jeff. No probs there. They can wait. Still have original paint on the house. A friend that visited last week actually brought paint and brushes. But he didn't paint... No need for enemies with such friends.
Gunnar Englund
www.gke.org
RE: Electric lake?
You could mount them on a 1"x12" board about 10 feet long and let them float around the lake. Or better yet some solar cells and motor and let them cruise around the lake on their own ( like the automatic vacuume cleaners) . I am traveling or Iwould setch it up and post a conceptual design.
That would leave you in boat with the beer and making another plot of fish distribution.
RE: Electric lake?
RE: Electric lake?
RE: Electric lake?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
"It's the questions that drive us"
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
RE: Electric lake?
Mike Halloran
Pembroke Pines, FL, USA
RE: Electric lake?
RE: Electric lake?
You can all relax! No electric eels, no Nessie, no Godzilla. In fact, no nothing.
I followed advice from DaveScott and Smoked. I have fabricated a 2 m long pole (wood) with little hooks screwed to the ends. I also have two copper electrodes attached to insulated panel wire and attached to another couple of hooks. There is also a 0.1 microfarad/630 V capacitor to block DC. The copper electrodes hang from the hooks at the ends of the pole. I measured with a Metrahit 29S DMM. It has three voltage measurement methods; AC, combined AC/DC and DC. It is a 4 1/2 digit instrument and resolution is 10 microvolts.
Instead of measuring voltage between bottom (ground) and surface, I measured voltage gradient over the two metre distance defined by the pole.
Repeated measurements were taken across the lake. We were extra careful in the area pointed out by people that had experienced funny phenomena. The exact location is 59 20 14.2 N and 14 55 57.0 E.
We rotated the boat through all compass directions and we probed at different depths - the instrument was constantly showing less than 1 millivolt. On all ranges and with/without blocking capacitor. The same result all over the lakes.
It was only when we measured close to a pipe to one of the pumping stations that we got any indication. If we placed one of the electrodes just above the pipe and the other electrode 2 m perpendicular to the pipe we got 18 millivolts AC over two metres. A voltage gradient equal to 9 mV/m - hardly a problem for anyone. And, N.B. this is not where swimmers complain about "funny feelings". That is out in the middle of the lake where we indicated zero mV/m.
During all the measurements, we had one of the regular visitors swimming in the lake. He reported that he could feel the tingling as usual. So, we know that we did not measure when the lake was "at rest".
I close the case. There is no electricity in the "Electric Lake". What the swimmers feel is not an electric phenomenon. I start to wonder if it isn't a rural legend as opposed to an urban legend after all.
Gunnar Englund
www.gke.org
RE: Electric lake?
I hope you got some good photos for the 'pub'!
RE: Electric lake?
Dang! Gunnar.. Not very exciting..
I'm surprised as an investigator you haven't jumped in the lake to confirm tingling. Just have someone tie a rope to your leg so they can retrieve the body efficiently.
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com
RE: Electric lake?
We need to help you locate some fake (rubber) eels, some flash powder, and a couple of automobile batteries. Go out on the lake (with much hoopla about how you fixed a problem in your apparatus). Set off flash powder explosion, and arc weld/fuse/melt some wiring using car batteries. Tie the eels onto the ends of your "rig" and row like hell for shore. When you show people the rig, exclaim about freshwater electric eels. Then bundle things into your car, head for home, and wait for calls from the television networks.
RE: Electric lake?
It's called: The Mad Scientists' Club.
Easy reading, very creative, hilarious spoofs pulled by smart kids. (fiction, but I bet spawned from reality)
http://www.madscientistsclub.com/books.html
http:
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com
RE: Electric lake?
What if it suddenly took off into outer space, with you, your boat, pole and little hooks all in tow ?
RE: Electric lake?
This will probably expose a gap in my knowlege, but why are you just looking for AC and blocking any DC.
I would have assumed that with two identical probes any electrolytic voltages would be eliminated and also that a large variation in DC voltages may be a significant indication of something requiring more investigation.
The tingling sensation may imply an AC voltage, but another question may be, "Why does the DC cause a tingling effect that is normally associated with AC?"
I envy your boat rides. Wish I was there!
Respectfully
RE: Electric lake?
I killed a myth. And you want it to live! Even employ cheap and dirty tricks like fake electric eels, explosions, perhaps a UFO and - on top of that have it on national television.
Hmm..
Sounds like fun, actually. OK. I will see what I can do about it. Stay tuned.
Gunnar Englund
www.gke.org
RE: Electric lake?
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com
RE: Electric lake?
Wow, thank you! I'd forgotten about those books, I read (most of) them too...I need to order copies for my kids.
RE: Electric lake?
Gunnar Englund
www.gke.org
RE: Electric lake?
RE: Electric lake?
I think I could configure a system so it would measure the fields and quack in different tones that varied with the stength of the electrical field.
RE: Electric lake?
don't forget the flash powder ignition system.
RE: Electric lake?
That guy in the water there said it was tingling?
jraef; Yeah me too!
BJC; Yeah great idea. The powered rubber ducky could tow an electrode two meters behind for the gradient. It's eyes could flash (red) with rate depicting voltage.
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com
RE: Electric lake?
The guy in the lake is a lawyer. We talked about witness psychology. And he still says he feels the tingling. But he doesn't say it is due to electricity. He never did. Others did.
I find this very interesting. Actually, I think it is a parallel to magnetic field sensitivity (which I deny the existence of). This is a very small lake and people talk a lot to each other on the beach. Someone has felt something that he/she cannot explain. Someone has probably put forward that it must be the new pump station (it was installed last year) and that it must be "something electric". Theories like that catch on like praire fires if allowed to develop. I think/hope that my measurements and the full page article about it will put an end to that part of the speculations. But you never know - people love catastrophe theories.
Gunnar Englund
www.gke.org
RE: Electric lake?
I noticed you were pretty thorough measuring different depths, places, orientations, etc. But what about the time factor? I'm guessing the pumps don't all run continously.
I agree with Waross, too. Ditch the capacitor and look at the DC coming from the pipe's cathodic protection as well as AC.
RE: Electric lake?
the water is sooooo coooold, its the onset of hypothermia!
BTW, how is the fishing?
Scott
In a hundred years, it isn't going to matter anyway.
RE: Electric lake?
We made sure that the phenomenon was present when we measured by having our "human indicator" swimming in the lake. He said that the tingling was there all the time. The pipes are for two snow canons and they are never run during summer when people swim in the lake.
Re capacitor and DC/AC. I measured with and without capacitor. I also used the different modes (AC, AC/DC, DC) of the instrument. Zero in all cases.
Before the measurements, I had calibrated the measuring system in a plastic pool using the secondary voltage of a small transformer (yes, RCD used) ans two metal cylinders. I got the expected readings and the fact that we could see a small voltage gradient (9 mV/m) close to the pipe serves as an extra confirmation.
An experiment that we didn't do was to use our "human indicator" in other lakes and see if he feels the same thing there. That ought to be done.
Gunnar Englund
www.gke.org
RE: Electric lake?
Many snow making systems are large motors and use solid state soft starters. Assuming they are left energized when not in use (not a good idea, but let's run with it), SCRs and their snubber circuits have leakage current. If the motor winding insulation was damp and leaking to the frame a little as well, it could be getting to the pump somehow (solid coupling, shaft grounding bushings etc.) and would eventually make it out to the pipes (assuming they are metal). A simple test would be to ask the snow equipment owner to open the circuit breakers (if they aren't already) and see if it goes away.
Why that would be picked up by a swimmer I have no idea, they would be at the same potential as the water, no?
http:/www.jraef.com
Eng-Tips: Help for your job, not for your homework Read FAQ731-376
RE: Electric lake?
We need to capitolize and form a bottling company. We need a catchy name and a bottle that looks like a battery. Go back to the lake and do some more research, this time take some of the Sweedish bikini team we'll need the pictures for the bottle label.
I am sure this stuff will also cure everything from toe nail fungus to dandruff.
Where do I send my money?
RE: Electric lake?
Any factories or manufacturing going on around that lake ?
How about mild stings from Jellyfish or something similar ?
RE: Electric lake?
I think it's time for skogs to take a dip...
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com
RE: Electric lake?
I am glad that you abandoned the rubber duck theme and turned to something more lucrative. Yes, it cures toe nail fungus and dandruff, and also incapacities in-between - if you see what I mean. You can send the money to me.
Warpspeed,
No factories. Just a conference hotel. I have tasted the water. No problems. I think that we can bottle it without any further processing. No need to filter out yellyfish, they do not live in fresh water. You can send the money to me.
Smoked,
I wouldn't know about them li'l fish nibbling my hair. And, yes. I took a dip. Don't feel an eel and nothing else. You can send the money to me.
Jeff,
How, when, where, of whom, why did you take that photograph? I know it isn't you. And that grin indicates the bucketeer is fully aware of the purpose of the photographing. There is some residual voltage between pump/motor housing and ground. It is because there is a voltage drop in the PEN between transformer and the PCC where the pump is connected. But it results in no more than the now infamous 9 mV/m close to the pipe. Nothing in the lake. You can send the money to me.
I2R,
That's a very probable reason. But the water is quite warm by our standards - about 22 celsius. The fishing was lousy. Probably because of the electric environment. You can send the money to me.
To all, and Jeff in particular. I think that we have lots and lots of abalone eggs floating around in the lake. That's probably what the customers feel.
I think it is time to close this thread. I thank you all for invaluable help in establishing a workable theory, designing measurement equipment, evaluating results and being helpful in general. And, by now, you know where to send the money.
Gunnar Englund
www.gke.org
RE: Electric lake?
RE: Electric lake?
Gunnar Englund
www.gke.org
RE: Electric lake?
I came to think his problem could have been solved with a tin foil hat. Maby your swimmer could have used a similar cure.
RE: Electric lake?
----------------------------------
I don't suffer from insanity. I enjoy it...
RE: Electric lake?
jsolar
RE: Electric lake?
Really did not want to kick it around any more , but I did a search and came up with this.
http:
I always knew the water was cool due to significant shrinkage.
Chuck
Getting older is inevitable
Acting your age is optional
RE: Electric lake?
Gunnar Englund
www.gke.org
RE: Electric lake?
RE: Electric lake?
Gunnar Englund
www.gke.org
RE: Electric lake?
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Electric lake?
Gunnar Englund
www.gke.org
RE: Electric lake?
RE: Electric lake?
Scott
In a hundred years, it isn't going to matter anyway.
RE: Electric lake?
Those Locke Ness monster stories get me every time.
Chuck
Getting older is inevitable
Acting your age is optional
RE: Electric lake?
It is WORSE - it is full of micro-shrimps!
A limnologist and science teacher (Olle Olofsson) has found the little creatures responsible for the "Electric Lake" rumour. There are lots and lots of little shrimp-a-like animals (Latin: Holopedium gibberum) that live in a large school in the middle of the lake.
They surround themselves with watery jelly blobs and are next to invisible in the water. But you can feel them between your fingers. Most people blamed electricity. And that is very typical, when there's no known explanation people tend to blame electricity or magnetic fields.
There is a good article about the organism in http
Gunnar Englund
www.gke.org
RE: Electric lake?
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com
RE: Electric lake?
Gunnar Englund
www.gke.org
RE: Electric lake?
Does the tingling get stronger during the night (or weaker during the day)? What leads everyone to believe these shrimp are causing the feeling... are they scratching/biting people?
You could get a similar tingling feeling if tiny bubbles were sent through the water from below. The bubbles slink along your body and provide just enough pressure to feel like little pin pricks.
Dan - Owner
http://www.Hi-TecDesigns.com
RE: Electric lake?
2. There are lots of H. gibberum in the water samples taken.
Gunnar Englund
www.gke.org
RE: Electric lake?
Dan - Owner
http://www.Hi-TecDesigns.com
RE: Electric lake?
"Tingling" does not, according to my dictionary, imply "electric sensation" it just means "a prickling, itching or stinging sensation".
"Tingling" was the closest translation of "kvillrande" but in matters like these, translation is no longer an exact science.
"a tenuous connection, at best" ???
Gunnar Englund
www.gke.org