Ejector Pump help on 16 Unit

[Joel Florek]

I am hoping to get some help. I have a 16 unit building that utilizes an ejector pump to pull the sewer from the property to the cities pipes. Its about a 6 foot rise. Needless to say I have been fighting with bill after bill for the pump getting clogged(probably $1200 this year between 7 repairs). Even putting in a second pump as a backup hasn't helped the problem and resulted in burning out the primary when it clogged. 

I am hoping for some suggestions on a proven system that works to deal with the waste of 16 units and doesn't result in the amount of clogs I have been dealing with. 

Any suggestions would be extremely helpful! 

As a note, I am located in Iron Mountain MI so I deal with all ranges of seasons.