exclusive easement

I am in Winchester VA and I have A BIG problem. My neighbor came to me about 3 weeks ago and stated they had made modifications to my easement on his property. they also stated they were going to put a fence across our border. I stated as long as he leaves the easement alone. Last Saturday, they had a company put in the fence going across the easement when the builder drilled they may or may not have hit my septic line ( the post is less than 3 inches), but the post is anchored in concrete which may affect the line. They also let them put the posts for the fence on the easemetn before distrubuting them. The easement is listed in his plot survey when he bought the house as well as mine as a "20ft x 225ft easement for alternative sewer system use" By changing the layout of the easement and by putting up the fence thus blocking me, the person I pay to maintain my septic system, and the Virginia Health department. I could lose my permit for the system. And if I lose the permit for the system, I could lose the ability to occupy my house. I confronted him lasst Saturday when they were putting up the fence, before they drilled. I asked him "what about my easement?" He stated he talked to his lawyer and he was entitled to do what he did. . He stated "You could pay for a gate in the fence." I said "I could pay? I never gave you permission to do anything to the easement. I want no fence on the easement. You are harming my ability to live. And this is Virginia, you can't be doing this??!! " (gesturing to the easement) At that point I walked away. He went to the builder and had them put a gate in the fence over the easement.
I was researching regarding the problems with him modifiying my easement and what it might do to me. But now, it seems he just doesn't care what it does to me.
I am also in the process of getting my contract for service renewed on my septic system and renewing my virginia septic discharge permit. What remedies can I seek?

In VA, the plot surveys are on record in the circuit cleck's office and incorporated into the deeds. In meeting the realtor who sold the property to my neighbor as well as talking to my neighbor. I offered to buy property my easement was onand around to try and make 'things easier between us' Each time I offered I was refused. I said ok, no problem, as long as you know the easement is used for my septic system and I have a lot of regulations on me about the system and how it performs.