Re[2]: a generic water encapsulation technique [Re: floods]

[pkavi () pcmail casc com]

Peter,

What you said is true if the drain system treats all fluids equally.  But 
consider the difference between these fluids.  

It is much more important that sewage water, with its Constant Flow Rate, get to
its intended destination and not leech its pollutants into the ground.  Storm 
water, with a bursty Variable Flow Rate, will not cause environmental damage if 
leeched into the ground during overflow cases.  What is needed is a drain system
which can distinguish between storm water and sewage.  

Prabhu
 

______________________________ Reply Separator _________________________________
Subject: Re: a generic water encapsulation technique [Re: floods]
Author:  peter () tdi net at SMTPLINK
Date:    4/10/97 10:56 PM


Kent W. England wrote:
> We could also multiplex the rain water with the sewage water in a
> multi-mode drain system. Internet drain specialists tend to take religious 
> points of view on whether we should have separate drain systems, should
> combine them, or outlaw one in favor of the other. But, clearly, 
> encapsulation is the favored approach.
     
The multiplexed drain system will never work.  Sewage water we know
to be a fairly constant flow over time,  and in fact sanitary engineers 
refer to it as having a Constant Flow Rate.  Storm water, on the other 
hand, is
very bursty in nature, and sanitary engineers describe that as Variable 
Flow Rate.  In the old days they tried combining drain systems, sharing 
the resources between the CFR water and the VFR water, and called the 
result AFR (or 
available flow rate).  AFR had one weakness, however: it relied upon a 
phenomena called precipitation shaping to keep the VFR storm water from 
interfering with the CFR sewage water.  As the clouds and the ground 
didn't 
have enough buffering to do proper precipitation shaping, the result was 
a drain system which periodically suffered massive congestion, and all 
users were equally unhappy.
     
-peter
     

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