Sewer Issues

We have lived in this house for 30 years, moved in 1986. We have had six sewage backups into our basement, of varying degrees. One in 1995, one in 1996, two in 2013 and two in 2015. 
Several neighbors have also had the same problems. Our sewer company Metropolitan Sewer District, MSD, hired a plumbing contractor in 2013 and installed a back-flow prevent valve. This was supposed to fix all our problems. 


It didn't work and several neighbors failed also. 
So now the latest fix is MSD hired a contractor to install a tank, pump, etc. this has supposedly disconnected us from a gravity sewer system and now our sewage is pumped into the main. 

I wonder if this fix will work. Time will tell.

Update:

It didn't take long for this new system to be tested. We had 4" - 5" of rain on August 15. Several neighbors had sewage in their basements. Our basement stayed dry. So I guess the new system has worked. We feel sorry for the neighbors.