My just got a condo late March this year, and early May the condo association told me there was a leakage in my kitchen faucet / garbage disposal that led to water leakage in the units underneath me (two units since the middle unit is vacant and they didn't realize).

If there was leakage and you buy the property , the costs could be in the hundreds of thousands 

How much higher is the ground above the concrete around the foundation at the point of leakage

Here are some of the numbers. 4 Bedrooms 3.5 bathroom row houseUnder contract at $109,900 purchase costComps & ARV $126,000Conventional loan at 20% & 5.8% interest, 30 yearsFull seller’s helpInitial estimated cost of repairs: $5000 (however now unsure due to foundational and roof issues)Anticipated cash flow: $284Major issues: There was significant ponding and evidence of leakage on roof.

1 - nuclear power plant2 - nuclear storage3 - nuclear leakage

A sump pump would be used to drain leakage in the basement, not sewage.

I tighten the nut, the water leakage stopped. 

Depending on the area, the city/county health inspector may actually choose to be there for the removal (not fun), but in our cases there was no leakage.

And some fiberglass or,  better, rockwool insulation to fill up weight cavities in old sash windows.I know the salesman who came out and carefully measured your windows before giving you a quote offered you a careful spiel about thousands of dollars of possible leakage and damage and insurance and a bunch of other vague warnings.

A basement may be used for habitable rooms or a dwelling unit, regardless of the depth of the floor below grade, if the floors and walls are impervious to leakage of underground and surface water and are protected from dampness, and if the required minimum 13-172-130, or by other approved means. 13-172-070 Natural light.