A bill to allow Colorado property owners the right to
utilize ‘graywater’ has been sent to Govenor Hickenlooper for his signature. The use of graywater will protect Colorado’s
vital water resources, help property owners and municipalities cut costs, and
aid property owners in green building certification.
Graywater generally refers to water that is drained from lavatories
(bathroom sinks), baths, showers, washing machines, and sinks. Water drained from kitchen sinks, water
closets (toilets), urinals, and dishwashers is generally called ‘blackwater’.
Graywater can be used flushing toilets and urinals and for
certain types of irrigation. Primarily graywater is used for subsurface watering
of trees and plants.
In House Bill 13‑1044, the legislature has defined graywater
as discharge from bathroom and laundry room sinks, bathtubs, showers, laundry
machines, and other sources that may be authorized by rule. The legislature has determined that the
wastewater from toilets, urinals, kitchen sinks, dishwashers, and non-laundry
utility sinks is not graywater. HB 13‑1044.
Savings
A primary savings from the use of graywater is lower water
use. Water currently used for irrigation
is fresh/treated, water bought and paid for from a municipal water system. Such water can be prohibitively expensive for
users where municipalities have invoked drought condition progressive pricing. A property owner can save money on his bill
by reusing water that he has already paid for.
Graywater can also save municipalities money. Water discharged from a home or commercial
building must be treated before returning it to use. Graywater used for irrigation rather than
sent to a treatment plant can reduce municipal costs. Municipalities may be able to postpone or
avoid the building of new treatment plants thanks to reduced treatment needs.
Costs
Graywater can be used for flushing toilets and for
irrigation. However, graywater is not
generally usable directly from the fixture.
It must be collected and treated.
Graywater collection will require a separate plumbing system
in a home or commercial building.
Normally, all wastewater, regardless of its origin, is discharged
through a single piping system. A separate system of piping and holding tanks
will be required.
You’ll need settling and filtering systems. The complexity and cost of your pumping and
piping system will depend on the size and configuration or your building and your
planned uses for gratwater.
Graywater use is approved by LEED for obtaining
certification as a green building.
LEED certification is based on a point system for
constructing and operating buildings in an environmentally friendly
manner. Points can be awarded for the
up-front reduction in water use and for the reduction in water treatment.
Legislation is
Necessary for Graywater
Water in Colorado is appropriated on a first-come
first-served basis. All of the water in
Colorado streams and rivers is already owned by someone, including a provision
for water staying in the river for fish and plant life. If you want to use water for some new
purpose, you have to buy a right to the water from a current owner of water
rights.
For example, if a ski resort wants water for snowmaking, it
cannot just pump water from a river and use it.
The resort must buy a right to that water from a farmer or other water
right owner.
Water appropriations are based on net water use. An appropriation includes not only taking water
from, but also return of water to the system.
A building owner’s water use can be calculated by subtracting the amount
of water he sends to a treatment plant from the fresh water taken into his building. Thus, reusing water would lessen the owner’s
return water flow, increasing his net water use and possibly exceeding his
appropriation.
The Colorado Legislature has made certain declarations to
allow property owners to reuse water:
- that graywater use is
essential to the future of the State;
- that property owners using
graywater do not violate another’s water rights, subject to municipal
policies that may require augmentation of the owner’s water return
obligations;
- that properly treated
graywater does not cause harm; and
- graywater is not to be
considered ‘reuse’ as defined under Colorado’s water law.
Congratulations to the Colorado legislature for taking this
important step to conserve our natural resources.
