WATER MAIN BREAK FORENSICS - WHO DUNIT?

The water main break on March 6, 2008 in Cleveland’ Public Square is going to wring a lot of money out of a lot of water rate payers and other taxpayers and businesses in the downtown area.  I’ll bet the cost is over a million dollars by the time all the public and private impacts are assessed.

 

The photo above was taken on the morning of the 6th and shows the broken 30 inch diameter main still spilling water into the pit.   Since the pit is self draining, there must be other passageways lower than the pipe into which the water is flowing. 

 

The Cleveland Water Department spokes person was quoted as attributing the break to “frost”  or “freezing” – and suggesting that the age of the pipe (over 100 years old)  played in the break.

 

I think that frost and age as causes for the break are much  less likely (very unlikely) than the fact that the Euclid Corridor work was just done right over this pipe. 

 

The concrete structure on top of the pipe in the photo has fallen from just under the street concrete down onto the pipe.    The structure dropping is not, however, what originally broke the pipe.   Observers of the water leak told of the pavement dropping down all at once, with a big whoosh-kerplump – that is when the concrete box dropped and smashed the hub of the water main.

 

So was this the location where the original break was?  

 

I can’t be certain.   But it might be.  But the break also may have been in an adjacent water line (you can see a broken 8 or 10 inch line in the photo - this could have been a cast iron gas line or water line), and, as the leak continued, soil was washed out from below the 30” line and down the drain lower in the pit, undermining the 30” line and deflecting it and causing to begin to leak .

 

You can see that the 30” pipe on the right hand side of the break is tipped downwards – meaning that the pipe is broken in a second place further out of sight to the right. 

 

If I could get in the pit - I went back on Friday but the police wouldn't let me get as close as I was on Thursday - I would collect each broken piece of the cast iron pipe [1]. I would look for any mark on the pipe which may have been made during the excavation for the installation of the new box-like concrete structure which has fallen on the pipe.      

 

From personal experience operating excavators, I know that one way to damage a cast iron pipe is to accidentally grab the pipe, or a hub joint on the pipe, with a tooth of the excavator bucket – and crack the pipe or the joint.  This could have happened when the excavation for the concrete structure was performed   last summer.   

The fact that the new concrete manhole was placed directly over the 30”  water main, and within a foot of the smaller water main, may be a sign that the survey/engineers where not aware of the location of the pipes.  It is not good engineering practice to place a new concrete vault structure so close to cast iron mains – and the bottom of the new concrete structure was within 2 feet or closer of the top of the 30”  water main.    

 

So will the City of Cleveland Water Department make any effort to determine the exact cause of the problem?   Will there be any effort towards accountability?  

 

What do you think?  

 

If you had to pay the bill, would you conduct   forensic engineering [2] to try to find out just why the line(s) broke?