On 10/20/2018 5:59 PM, trader_4 wrote:
On Saturday, October 20, 2018 at 5:00:56 PM UTC-4, micky wrote:
A guy on the radio saying, If you get 3 1/2 inches of rain in NYork,
that's 3 1/2 inches of rain washing all sorts of things into the
reservoirs in the Catskills, 3 1/2 inches of rain putting pressure on
treatment plants.

Huh.

Isn't everything that would be washed into the reservoirs already in the
reservoirs or there would be no water there either?

???
Those reservoirs are typically fed by streams or have water pumped into
them from rivers. If there is an exceptional, heavy rain, then more
undesirable, unexpected stuff can wash downhill in torrents and go
into the sources that feed the reservoirs.





And NYC doesn't treat rain water, does it? It just goes down the drain
and into the river or the ocean, right? There are septic sewers and
rain sewers and they're separate.

AFAIK, NYC uses a combined system. That's why there have been incidents
over the years where with an exceptional rain, the treatment facility
can't handle it and stuff, eg bags, bottles, plastic that was in the
storm drains winds up going into the rivers. I think that has gotten
better over the years, but again, AFAIK, raw water in exceptional cases
can wind up in the river.





I came in in the middle so I don't know who was saying this stuff.

Yea, Chicago has a combined (old) system. That's why they built the so
called "Deep Tunnel" project. It consists of water tunnels running all
over the place with drop shafts to take excess storm water in specific
areas where the rain was the heaviest. It was also to have several
"tanks" formed by old quarries where the rock had been removed, but I
don't think these have ever been used yet. The tunnel is so big that it
takes up the excess water/sewage and then, when the rain stops, the
water/sewage is pumped to the treatment plants. Expensive, but,
apparently less expensive than building a storm sewer system over the
whole city and nearby suburbs. I used to live in one of the nearby
suburbs and all our storm water went into the combined system, even
gutter water.