Please explain how it was an undisclosed easement? I am fairly certain if it is an easement, it is listed on your title insurance from when you purchased the home.
But more importantly, you knew there were gigantic utility poles and lines 48 feet from your property when you purchased. Or are you stating they were put up later?
If the poles were put up after you purchased, refer back to my first statement as to the easement most likely listed on your title insurance policy or disclosed on a survey possibly.
Even so, I am wondering how you think the power company will move these gigantic transmission lines away from your home.
Easements are disclosed by recording them in the public records. If the easement was recorded in the public records, you (and the rest of the world) had legal notice of its existence, whether or not you had actual knowledge of it. The fact that you have owned your property for five years has nothing to do with whether or not the easement is legal. If you think that the electric companies have acted illegally in putting up the poles, you should consult an experienced real estate lawyer in your area. Your lawyer can review your documents and advise you on the best way to proceed.
Disclaimer: This answer is provided for informational purposes only, does not constitute legal advice, and does not create an attorney-client relationship. Actual legal advice can only be provided after completing a comprehensive consultation in which all of the relevant facts are discussed and reviewed.
As disclosed by others, just because you didn't know about it doesn't make the easement undisclosed. That having been said, your concern is the adverse health effects from the EMF radiation. There are many peer-reviewed scientific articles available, some for free, which discuss the levels of exposure that are within scientifically-accepted "safe" ranges. If you truly believe that you are suffering from over-exposure, you should immediately have the levels in and around your home tested to ensure that they are within acceptable limits. If not, then you can go to the City and ask that TECO be made to reduce the levels of EMFs radiating from the poles adjacent to your home. Chances are good that even though you hear that annoying crackling sound coming from the wires, the exposure at your home is within acceptable limits. But, maybe not. Best to check and make sure. BTW, I have to ask - do you use a cell phone?? They also emit RFs that are consistent with some level of (potentially) dangerous exposures. If all the exposures are in acceptable limits, my advice to you is to either learn to accept it or sell your home.
My answer is of a general nature and should not be construed to be legal advice nor creating an attorney-client relationship. Carol Johnson Law Firm, P.A. practices in the area of Wills, Trusts, and Estates, Disability - with a particular focus on providing Special Needs Trusts for disabled children and adults.
The fact that you have lived on the property for 5 years has no bearing in this case. What is important in this scenario is if there is an existing easement and the nature of that easement. The starting point is to check the survey you had done when you purchased the home, which would have indicated its inclusion. If you didn't do a survey or lost it, then check your title insurance policy. Any easement on the property would have been listed among your policy's exclusions. All easements have to be recorded in your county's public records. Your title policy should indicate the book and page number where the original document for the easement is recorded in public records. You can then look up the record and check to see the nature of the easement i.e. is it a utility easement, drainage easement, sewer easement, and are the rights acquired under the easement unrestricted or restricted in some way. If there is in fact a utility easement, chances are the electric companies are acting within their rights and there isn't anything you can do about it. However, if that is not the case and for example, the electric companies have placed their poles in an easement for a drainage purposes, now you may have an inverse condemnation claim and you should contact an attorney who handles eminent domain.
Please note that the above is not intended as legal advice, it is for educational purposes only as to the limited amount of facts provided. No attorney-client relationship is created or is intended to be created hereby. You should contact a local attorney to discuss and to obtain legal advice.