That grey plastic shield down the side of the power pole covers a copper conductor coming from the neutral tap of the transformer on the power pole. Before the late 1970s’and the advent of high frequency voltage transients, also known as dirty electricity (DE) utility power when out to the customer, was used and returned to the utility via the wires on the poles. Once the USA started using energy efficient electronic devices with switch mode power supplies and pulse width modulators in variable speed motors the electricity got very dirty at the point of use. This dirty electricity is loaded with high frequency voltage transients (DE) and does like to travel back on standard size utility neutral wires and it caused overheating.
Utilities started having problems with the grid they designed for pre-1980, clean electricity of mostly 60 Hz (cycle) wave form: wires were overheating.
The new & dirty return current with DE in it would not go back on the lines without over heating the utility wires because there is a large amount of harmonics (0 – 3,100 Hz) and DE (3,100 – 200,000 Hz).
This meant that the utilizes would have to take one of several options some of which are costly to themselves.
1. Increase neutral return line size: expensive & may not fit on pole.
2. Add additional neutral return lines: expensive & may not fit on pole.
3. Inject the return current into the earth and let the neutral return current find it way back to the substation via the earth or other conductive pathway. Very Cheap and easy to install! This is the grey plastic covered conductor in this video. You can hear the dirty current on an AM radio tuned below 540 on the dial.
In 1992 most public utility commissions gave electric utilities legal permission to do the following: put electricity into the ground rather put up a wire to bring it back to the substation. The utilities call this “stray voltage” but we all know who makes the electricity so we know who it belongs to. Along with stray voltage there is stray current flowing under your feet: it can flow up one leg and down the other, through your body making you part of the circuit. There is nothing stray about it as electricity follows the laws of physics and goes were people put it. It is allowed and put into the ground by those politicians and utilities that are more concerned with utility profits than biological health.
By running a conductor from the neutral tap of the transformer to a copper ground rod in the earth the return current can now use the soil under your feet, house and back yard as a pathway to complete the circuit and return to the utility. Can you imagine the uproar that would happen if the municipal water and sewer districts were allowed deliver and receive fluids this way? The electric utilities saving grace is “electricity is invisible” and politicians and bureaucrats are their side.
This saves the utility so very much money but it creates a lot of damage to creatures walking on the earth. Dairy farmers in Wisconsin and Michigan noticed that cows were dying much too soon, had many not seen before joint aliments and were producing much less milk that a few years before when the electricity was clean and not directed into the earth. Humans and other creatures, walking on the ground, were also suffering. The social cost of this political favor to the electric utilities is many times more than the cost of installing adequate neutral return wires but that would be an expense to the electric utility.
Pioneers in this specialty field like David Stetzer were able to prove in court that a 10 mili volt transient on the milking parlor floor is correlated to a reduction of milk output. Dairy farmers go settlements of over $100,000,000 Stetzer has videos of horses kicking up their heels at the same time that the oscilloscope registers an increase in DE in the ground. The horses are trying to break contact with the electrically charged ground under hoof.
In everyday residential settings this can lead to electric current coming into your house and under your house via any conductive pathway such as a water pipe, gas pipe, swimming pool grounding system or even a metal chain link fence.
Recently in Chico Ca I measured 30 µAMPs of 10 KHz dirty electricity coming through my bare feet resting in a tile floored house with a slab on grade foundation. This is called Contact current. The NIEHS recognizes that at or above 18 µAMPS of contact current through the body is correlated to cancer in many well programed studies.