Basement seepage in Cleveland Rental_$36,000 estimate WTH?

[Tim Greenfield]

I purchased home in Euclid in Summer of 17 and it has been cash flowing nicely and it is in a nice neighborhood where I would even want to live. It was a complete rehab and the provider stated that there were repairs done to the basement. The property inspector noted the wall as having been recently repaired and some of the block had white efflorescence and there was some visible signs of water intrusion from stains on the wall. He was unable to ascertain the extent or how often it occurs but stated that the area should be monitored and repaired as needed. Fast forward to this week and I get an email from the PM that the tenant stated that due to the rainy season" they are having water coming into the basement. Further, that the basement needs waterproofing and the block is changing color possibly mold." 

She sends a vendor out there who gives a quote for $36,094. The GC stated that the wall is is wet from but not other entry is noted. I call this BS. I have never had a basement nor lived in Cleveland so I am looking for some advice. I did walk this house prior to purchase. The tenant has been in there since summer of 17 and never called this out before. I have reviewed the property inspection and just noticed that it does not have a sump pump so I will install this and also a battery backup as I have in my other houses in the Cleveland area.

Does anyone have any experience with this? I am assuming with the area and the age of the houses that this is common and only occurs when there is heavy rain. At what point do you consider a complete excavation as this contractor is suggesting? Are there more economical alternatives to sealing a wall without using a backhoe and a building foundation excavation? This is also a GC not a basement expert.

V/r

Tim