United States
Protection Agency
           Water Division Region IX - EPA 909-F-98-001


"Water recycling is a critical element for managing
our water resources. Through water conservation
and water recycling, we can meet environmental
needs and still have sustainable development and a
viable economy."

      —Felicia Marcus, Regional Administrator
Front Cover—The Experience at Koele Golf
Course, on the Island of Lanai, has used recycled
water for irrigation since 1994. The pond shown is
recycled water, as is all the water used to irrigate
this world-class golf course in the state of Hawaii.

                                                        Water Recycling and Reuse:
                                                        The Environmental Benefits
                  What Is Water Recycling?
Recycle: verb 1. a. To recover useful materials from garbage or waste.
                b. To extract and reuse.

While recycling is a term generally applied to aluminum cans, glass bottles, and
newspapers, water can be recycled as well. Water recycling is reusing treated
wastewater for beneficial purposes such as agricultural and landscape irrigation,
industrial processes, toilet flushing, and replenishing a ground water basin (re-
ferred to as ground water recharge). Water is sometimes recycled and reused
onsite; for example, when an industrial facility recycles water used for cooling
processes. A common type of recycled water is water that has been reclaimed
from municipal wastewater, or sewage. The term water recycling is generally
used synonymously with water reclamation and water reuse.

Through the natural water cycle, the earth has recycled and reused water for mil-
lions of years. Water recycling, though, generally refers to projects that use
technology to speed up these natural processes. Water recycling is often charac-
terized as "unplanned" or "planned." A common example of unplanned water
recycling occurs when cities draw their water supplies from rivers, such as the
Colorado River and the
Mississippi River, that
receive wastewater dis-
charges upstream from
those cities. Water from
these rivers has been  re-
used, treated, and piped
into the water supply  a
number of times before
the last downstream user
withdraws the water.
Planned projects are
those that are developed
with the goal of benefi-
cially reusing a recycled    „ D , ,,  , ,, ,   „   .   „ .   ,
    J       °     J        1 he Palo Verde Nuclear (generating Station, located near Phoenix Arizona, uses
Water Supply.              recycled water for cooling purposes.

Water Recycling and Reuse:
The Environmental Benefits
          How Can Recycled Water Benefit Us?
Recycled water can satisfy most water demands, as long as it is adequately
treated to ensure water quality appropriate for the use. Figure 1  shows types of
treatment processes and suggested uses at each level of treatment. In uses where
there is a greater chance of human exposure to the water, more treatment is re-
quired. As  for any water source that is not properly treated, health problems
could arise from drinking or being exposed to recycled water if it contains
disease-causing organisms or other contaminants.
Treatment: |
•No uses
at this level

Suggested Water Recycling Treatment and Uses*


Increasing level of treatment
Secon dary Treatment :
^ BiologicalOxidation, J
•Surface irrigation of
orchards and vineyards
•Nonfood crop irrigation
•Restricted landscape
•Groundwater recharge
of nonpotableaquifer**
•Wetlands, wildlife
habi tat, stream
•Industrial cooling

Tertiary/Advanced Treatment:
^. 1. Chemical Coagulation, Filtration, Disinfec-
•Land scape and golf «Indirectpo table
course irrigation reuse: Groundwater
•Toilet flushing recharge of potable
•Vehiclewashing aquiferandsurface
•Food crop irrigation water reservoiraug-
•Unrestricted recrea-
tional impoundment

*Sug gested uses are based on Guide-
lines for Water Reuse, developed by
Increasing level of hu man exposure -^. * *Rec om mended level of treat ment is

Figure 1: While there are some exceptions, wastewater in the United States is generally required to be treated to the
secondary level. Some uses are recommended at this level, but many common uses of recycled water such as landscape
irrigation generally require further treatment.

The US Environmental Protection Agency regulates many aspects of wastewater
treatment and drinking water quality, and most states have established criteria or
guidelines for the  beneficial use of recycled water. In addition, in 1992, EPA de-
veloped a technical document entitled "Guidelines for Water Reuse," which

                                                           Water Recycling and Reuse:
                                                           The Environmental Benefits
contains such information as a summary of state requirements, and guidelines
for the treatment and uses of recycled water. State and Federal regulatory over-
sight has successfully provided a framework to ensure the safety of the many
water recycling projects that have been developed in the United States.

Recycled water
is most com-
monly used for
nonpotable (not
for drinking)
purposes, such
as agriculture,
landscape, public
parks, and golf
course irrigation.
Other non-
potable  appli-
cations include
cooling water
for power plants
and oil refiner-
ies, industrial
process water
for such facili-
ties as paper
mills and carpet dyers, toilet flushing, dust control, construction activities,
concrete mixing, and artificial lakes.

Although most water recycling projects have been developed to meet nonpotable
water demands, a number of projects use recycled water indirectly1 for potable
purposes. These projects include recharging ground water aquifers and augment-
ing surface water reservoirs with recycled water. In ground water recharge
projects, recycled water can be spread or injected into ground water aquifers to
augment ground water supplies, and to prevent salt water intrusion in coastal areas.
1 Indirect potable reuse refers to projects that discharge recycled water to a water body before
  reuse. Direct potable reuse is the use of recycled water for drinking directly after treatment.
  While direct potable reuse has been safely used in Namibia (Africa), it is not a generally
  accepted practice in the United States.
The Irvine Ranch Water District provides recycled water for toilet flushing in high rise
buildings in Irvine, California. For new buildings over seven stories, the additional cost
of providing a dual system added only 9% to the cost of plumbing.

Water Recycling and Reuse:
The Environmental Benefits
For example, since 1976, the Water Factory 21 Direct Injection Project, located
in Orange County, California, has been injecting highly treated recycled water
into the aquifer to prevent salt water intrusion, while augmenting the potable
ground water supply.

While numerous successful ground water recharge projects have operated for many
years, planned augmentation of surface water reservoirs has been less common.
However, there are some existing projects and others in the planning stages. For
example,  since 1978, the upper Occoquan Sewage Authority has been discharging
recycled water into a stream above Occoquan Reservoir, a potable water supply source
  For over 35 years, in the Montebello Forebay Ground Water Recharge Project, recycled water has been applied to
  the Rio Hondo spreading grounds to recharge a potable ground water aquifer in south-central Los Angeles County.

for Fairfax County, Virginia. In San Diego, California, the Water Repurification Proj ect
is currently being planned to augment a drinking water reservoir with 20,000 acre-
feet per year of advanced treated recycled water.

                                                         Water Recycling and Reuse:
                                                         The Environmental Benefits
                 What are the Environmental
                 Benefits of Water Recycling?
In addition to providing a dependable, locally-controlled water supply, water
recycling provides tremendous environmental benefits. By providing an addi-
tional source of water, water recycling can help us find ways to decrease the
diversion of water from sensitive ecosystems. Other benefits include decreas-
ing wastewater discharges and reducing and preventing pollution. Recycled
water can also be used to create or enhance wetlands and riparian habitats.

                  Water recycling can decrease diversion of
                    freshwater from sensitive ecosystems.

Plants, wildlife,  and fish depend on sufficient water flows to their habitats to live
and reproduce. The lack of adequate flow, as a result of diversion for agricul-
tural, urban, and
industrial pur-
poses, can
cause deteriora-
tion of water
quality and eco-
system health.
Water users can
their demands
by using recy-
cled water,
which can free
amounts of wa-
ter for the
and increase
flows to vital
                                  Copyright 1994, Mono Lake Committee
In California, Mono Lake's water quality and natural resources were progressively declining
from lack of stream flow. In 1994, the Los Angeles Department of Water and Power was
required to stop diverting one-fifth of the water it historically exported from the basin. The
development of water recycling projects in Los Angeles has provided a way to partially offset
the loss of Mono Basin water, and to allow the restoration of Mono Lake to move ahead.

Water Recycling and Reuse:
The Environmental Benefits
        Water recycling decreases discharge to sensitive water bodies.

In some cases, the impetus for water recycling comes not from a water supply
need, but from a need to eliminate or decrease wastewater discharge to the
ocean, an estuary, or a stream.

For example, high volumes of treated wastewater discharged from the San
Jose/Santa  Clara Water Pollution Control Plant into the south San Francisco Bay
threatened  the area's natural salt water marsh. In response, a $140 million recy-
cling project was completed in 1997. The South Bay  Water Recycling Program
                                                                  Incline Village,
                                                                  Nevada, uses a
                                                                  wetland to
                                                                  dispose  of
                                                                  effluent, expand
                                                                  the existing
                                                                  wetland habitat
                                                                  for wildlife, and
                                                                  provide  an
                                                                  experience for
has the capacity to provide 21 million gallons per day of recycled water for use
in irrigation and industry. By avoiding the conversion of salt water marsh to
brackish marsh, the habitat for two endangered species can be protected.

              Recycled water may be used to create or enhance
                   wetlands and riparian (stream) habitats.

Wetlands provide many benefits, which include wildlife and wildfowl  habitat,
water quality improvement, flood diminishment, and fisheries breeding

                                                            Water Recycling and Reuse:
                                                            The Environmental Benefits
grounds. For streams that have been impaired or dried from water diversion, wa-
ter flow can be augmented with recycled water to sustain and improve the
aquatic and wildlife habitat.

              Water recycling can reduce and prevent pollution.

When pollutant discharges to oceans, rivers, and other water bodies are curtailed,
the pollutant loadings to these bodies are decreased. Moreover, in some cases,
substances that can be pollutants when discharged to a body of water can be
beneficially  reused for irrigation. For example,  recycled water may contain
higher levels of nutrients, such as nitrogen, than potable water. Application of re-
cycled water for agricultural and landscape irrigation can provide an additional
source of nutrients and lessen the need to apply synthetic fertilizers.
 Recycled water has been used for a number of years to irrigate vineyards at California wineries, and this use is
 growing. Recently, Gallo Wineries and the City of Santa Rosa completed facilities for the irrigation of 350 acres of
 vineyards with recycled water from the Santa Rosa Subregional Water Reclamation System.

Water Recycling and Reuse:
The Environmental Benefits
       What Is The Future Of Water Recycling?
Water recycling has proven to be effective and successful in creating a new and
reliable water supply, while not compromising public health. Nonpotable reuse
is a widely accepted practice that will continue to grow. However, in many
parts of the United States, the uses of recycled water are expanding in order to
accommodate the needs of the environment and growing water supply de-
mands. Advances in wastewater treatment technology and health studies of
indirect potable reuse have led many to predict that planned indirect potable re-
use will soon become more common.

While water recycling  is a sustainable approach and can be cost-effective  in
the long term,  the treatment of wastewater for reuse and the installation of
distribution systems can be initially expensive compared to such water sup-
ply alternatives as imported water or ground water. Institutional barriers, as
well as varying  agency  priorities, can make it difficult to implement
water recycling projects. Finally,
early in  the planning  process,
agencies must implement public
outreach to address any concerns
and to keep the public involved in
the planning process.

As water demands and environmental
needs grow, water recycling will play
a greater role in our overall water sup-
ply. By working together to overcome
obstacles, water recycling,  along with
water conservation, can help us to
conserve and sustainably manage our
vital water resources.
       At West Basin Wastewater Treatment Plant in
       California, reverse osmosis, an advanced
       treatment process, is used to physically and
       electrostatically remove impurities from the

                                                       Water Recycling and Reuse:
                                                       The Environmental Benefits
For more information about water recycling and reuse, contact:

Nancy Yoshikawa
US Environmental Protection Agency, Region IX
Water Division
75 Hawthorne Street
San Francisco, CA 94105
Tel: (415)744-1163

EPA Material:

Guidelines for Water Reuse. US EPA Office of Technology Transfer and Regula-
tory Support. EPA/625/R-92/004. September 1992.

Municipal Wastewater Reuse: Selected Readings on Water Reuse. Office of Wa-
ter (WH-595) EPA 430/09-91-002. September, 1991.

Other related literature and videos:

Layperson's Guide to Water Recycling and Reuse., published in 1992 by the Wa-
ter Education Foundation,  Sacramento, California.

Video, entitled Water from Water: Recycling, produced in 1995 by National Wa-
ter Research Institute, Fountain Valley, California.

Video, entitled, Water in an Endless Loop,  produced in 1997 by WateReuse
Foundation, Sacramento, California.