Effect of Natural Gas Pipeline on Property Values

[Larry P.]

I have a property in Charles County, MD that I just started rehabbing. I was contacted by an architect and engineering firm a few years back about their desire to do a geotechnical survey related to a potential gas pipeline across a 500-foot length of the edge of the property that would be within 75 foot of a single family 4 bed/4 bath home. I had not heard anything in a while so I thought they decided to do something different but  I got an email indicating they are scheduled to come out within the next week to actually do the survey.
 

Does anyone know how having an 18-inch high-pressure gas pipeline across your property affects property values and if it affects the ability to have certain loans, FHA, VA, HUD, conventional loans underwritten? At this point, I am not sure if I should put cash into it and sell it as quickly as possible or wait and see what they offer for an easement in the next few months before determining how much to put into it.