New York City's water supply system is considered to one of the
world’s most extensive urban water systems. This multifaceted system
relies on a combination
of tunnels, aqueducts and reservoirs to meet the daily
needs of 8 million residents and the many visitors. Resulting from its
well-protected wilderness watersheds, the Big Apple's water treatment
process is simpler than many other American cities. One primary advantage
of the system is that 95% of the total water supply is supplied by gravity.
The
remaining percentage needs to be pumped to maintain the desired pressure, which
is sometimes increased during times of drought when the reservoirs are at lower
than normal levels.
This system has been the purest
and most bountiful supply of drinking water in the United States. It utilizes
three separate systems of reservoirs which obtain water from some 2,000 square
miles of watershed in upstate New York. The three systems include the Croton
System, the Catskill System and the Delaware System.
About 50% of the city’s water comes from the Delaware system, 40% from
the Catskill system, and the remaining 10% comes from the Croton system. The
city now has 19 reservoirs; the farthest is 120 miles from central Manhattan.
This long travel time, which is powered by gravity, results in most of the
microbes dying naturally. The water is treated with chlorine to kill organisms,
fluoride to prevent tooth decay, sodium hydroxide to raise pH
levels, and orthophosphate, a substance that coats pipes, to prevent lead from
leaching into the drinking water.
New York City’s water, in the past, has won many awards for it’s taste,
and has long been toasted as "the champagne of drinking water" but in
years past has been documented that it has "lost it’s sparkle.”
New York’s water system is relatively old and the
aging system has to deal with an increasing city population. The 2013 ASCE
Report Card for the Nation’s Infrastructure stated that New York state need $27
Billion in infrastructure investments. Currently New York City is constructing
a new Water Tunnel No. 3 because the aging two current City tunnels are too old
for today’s stress. Water Tunnel No. 1 was completed in 1917 and Water Tunnel No. 2 was completed 1936. Water Tunnel No. 3 was
started in 1970 and will be completed in the year 2020.
It's one of
the biggest public works projects on earth - 60 miles long - and when it's
finished, it will have taken 50 years to build and cost $6 billion dollars. As reports, it all starts in upstate New York with a series of mountain reservoirs. There are watershed areas 100 miles north of New York City, with reservoirs at such high elevations that gravity alone carries the water down to the city with enough pressure that no pumps are needed.
But once the water gets to the city, it flows down into those two aging tunnels that have never been repaired or even fully inspected.
This is why the urgency for Tunnel No. 3 is so high.
Work on the new water tunnel has been going on since 1970, but it's far from finished.
