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News
CROWN
Solutions, Inc. Technical Resource
Money Down the Drain: The
True Value of Water
By James McDonald, PE, CWT
 Drip…drip…drip
or in some cases gush…gush…gush. Do you know what that
sound is? Money being poured down your drain! The true
value of water is far greater than the H2O molecules
alone. In some cases, the true value of water can be
as high as $30 per 1,000 gallons! What you don’t know
about water can cost you plenty. What you learn about
water can save you lots.
Water
is a utility, and like electricity and natural gas,
the more efficiently it is used, the more money that
is saved. What is the true value of water though? Is
it simply the value paid to the city for their “city
water”? Is it only the pumping costs for well water?
The answer to these last two questions is “NO!” What
else adds value to every drop of water used? You are
about to find out.
Usage
It is entirely possible that a company has no idea how
much water they are using. The water bill is received
and goes directly to accounts payable. Perhaps multiple
water bills are received, and they are never combined
to determine the total bill. Sometimes the rate is expressed
in cubic feet instead of gallons, which is confusing
for some. It is not unusual to find that no one in a
company is paying any attention to how much water is
being used and how much wastewater is being generated.
A mass balance of “water in” to “water out” has never
been generated. Extra wastewater surcharges may also
be ignored.
Why?
Why is water sometimes ignored? Water is cheap…or at
least it used to be viewed that way. This view has been
changing more and more each year. According to an article
in WaterWorld, November 2005, the costs of water and
wastewater combined rose an average of 5.3% in the last
year. That is nearly twice the Consumer Price Index
(CPI). The average price paid for water and wastewater
is $5.78 per thousand gallons. Some cities have rates
as high as $12.17 and some as low as $1.76 per thousand
gallons.
Water’s
Value
Water’s true value is more that what shows up on the
water and sewer bills received each month. The true
value of water includes the following: • Cost of water
(e.g., city or well pumping costs)
- Cost
of wastewater treatment (e.g., off-site or onsite)
- Surcharges
for special pollutants (e.g., Biochemical Oxygen Demand,
Chemical Oxygen Demand, etc.)
- Heat
(e.g., condensate, boiler blowdown, fuel costs)
- Chemicals
added to water (e.g., cooling tower chemistry, boiler
chemistry, process chemistry)
- Pretreatment
costs (e.g., softening, reverse osmosis, deionization,
etc.)
How
to Reduce True Water Costs
There are numerous ways to reduce true water costs.
Methods can be operational, chemical, or mechanical
in nature. In order to reduce water costs, one must
know the systems.
- Water
Mass Balance: Know the “water in” to “water out.”
If they don’t equal, find out why.
- Energy
Balance: Know what processes add or remove energy
from water. Boilers add heat while chillers take heat
away. Either way, it costs money to do this. Know
what energy is being wasted down the drain.
Each
piece of equipment is unique and has its own water saving
potential. Examples include:
- Boilers:
Decrease the blowdown by supplying high purity water
as makeup. Decrease blowdown by installing an automatic
blowdown controller to keep boiler cycles steady.
Decrease blowdown by increasing the condensate return.
Decrease blowdown by changing to more effective boiler
chemistry to increase cycles.
- Cooling
Towers:
Decrease blowdown by supplying higher quality makeup
water such as softened water. Recycle water to the
cooling tower such as reverse osmosis reject water
or treated wastewater. Decrease blowdown by using
more effective water chemistry to increase cycles.
Decrease blowdown by installing a better blowdown
controller. Convert once-through cooling applications
to cooling towers.
- Closed
Loops: Reduce makeup demand by using effective
corrosion inhibitors that will minimize leaks.
- Wastewater:
Reduce treatment costs by evaluating other chemistries.
Reduce treatment costs by properly feeding chemistries
(e.g., reduce flocculant sheer, fish eyes, inadequate
mix time, etc.) Reduce sewer costs by finding other
uses for treated wastewater (e.g., wash tanks, cooling
towers).
- Process:
Cascade baths from clean to dirty to reduce makeup
and sewer costs. Change water quality to extend bath
life or eliminate equipment damage.
 Fuel
Costs
A cost that can easily be overlooked when calculating
the true value of water is fuel cost. When dealing with
boilers, the hidden heat energy value can easily dwarf
the basic water/wastewater value seen on the water bills.
Reducing boiler blowdown and increasing condensate return
can have a significant effect on the bottom line of
operating a boiler system. With today’s natural gas
prices of around $12.50/MCF, the cost can be significant.
Example:
Condensate Return
As shown in the November
2004 issue of this newsletter, the value of condensate
can easily be $16.81 per 1,000 gallons. This includes
the cost of water, wastewater, pretreatment, and boiler
fuel. Adjusting this price with the modern day water/wastewater
and fuel costs brings this number to $30.31 per 1,000
gallons. This is 5.2 times more than the $5.78 per 1,000
gallons for the water/wastewater alone. Wow! Knowing
the true value of condensate can turn a project to increase
condensate return with a five-year simple return on
investment into a one-year return.
Conclusions
As shown, the true value of water cannot be ignored
and must be considered when evaluating the economic
health of any operation. With knowledge of water and
the systems, water usage can be economically fine tuned
to save money today and tomorrow. For more information
on water saving opportunities at your facility, contact
your local Water Management Specialist.
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