They have polluted your pool of buyer's. 

Laws were passed by good ol Bill White to cut down on street pollution and even set up a bandit sign enforcement team that WILL come looking for you.

It "oxidizes" the pollutants leaving you with fresh O2 to breathe and no smells!

It seems that municipal garbage services would be intrusive big government at its worst; the thin end of a socialist wedge that would deprive the citizens of their right to choose which noisy truck lumbered up to their house on a weekly basis ;These trucks get 2 mpgA single hauler need 5 trucks full time to replace 35 independent haulersThese are the biggest and heaviest trucks in neighborhoodsProbably there are 10 garbage trip per week on any given street versus 1These mom and pop trucks are the dirtiest polluters Garbage goes out on your block just one day a week.

My suspicion is they go under contract with a bid above asking price, and then during the close process, the buyers realize that they have to make up the difference in appraised value and can't.I currently have friends looking in the Globeville area (despite the I-70 expansion proposal and the pollution)...they've made multiple offers they've lost out on for the same reason you have.  

Typically in this scenario if it couldn't be sold by a realtor that means 1) The Tenant Owned Homes are very dumpy and would have to evict most people to get them fixed; 2) Lots of deferred capital improvements; or 3) Something massively wrong with the utilities, such as a Lagoon (very common in small Louisiana Parks) or failing septic / pollution concerns;To be fair a lot of residential realtors list smaller MHP's and don't know what they're doing, so it's possible that the realtor used the wrong keywords and it never hit the main advertising channels.

Everyone considering buying a "system", or finding themselves tempted by the "real estate educators" that sometimes pollute BP should save themselves a tremendous amount of money and heartache by stating with this book instead.Real Estate Finance & Investment Manual, by Jack Cummings.

But the air, land and water pollution issues are very challenging.

Or like superfund toxic pollution issues? 

All federal agencies utilize the tax code to make business applications, for example, someone who pollutes a river who is not in the business of doing the activity that caused the pollution ends up with a smaller fine, those who are in the business are then subject to much greater penalties for the violations.Folks might begin here starting a business and to see when and why dealing with the public is different than doing an occasional activity for themselves, like holding a garage sale. https://www.sba.gov/starting-business/learn-about-...:)PS: More bad news, someone who loans money or does an installment sale are bared from charging points, loan fees or other fees except for interest and late payment fees, why?