CLARK COUNTY, NEVADA
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environmental impact statement
Paul De Falco, Jr
Regional Administrator
October ei 1074
1OO California street san §rancisco ca
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ENVIRONMENTAL IMPACT STATEMENT
DRAFT (x) OCT 2 1 1974
FINAL ( )
Prepared by the United States Environ-
mental Protection Agency, Pacific South-
west, Region IX, San Francisco,
California 94111
1. Type of Action:
a. Administrative
2. Description of Project:
The objective of this project is to elimi-
nate existing secondary discharges from
municipal sources in the Las Vegas Wash/
Bay drainage area. Currently three sepa-
rate sewage treatment outfalls discharge
to Las Vegas Wash, providing a year-
round flow that supports a vegetative ha-
bitat similar to many lush riparian envi-
ronments and serving as a contrast to the
vast desert within which it sets.
Secondary effluent has been a major source
of accelerated water quality degradation in
Las Vegas Bay, where nutrients have sup-
ported algal blooms. Salt concentrations
in Las Vegas Bay have been accelerating
due to contributions from municipal sour-
ces, industrial sources, ground water re-
turn flows and other diffused sources.
A 180-day enforcement notice to clean up
all discrete discharges to the Wash was
issued by the Environmental Protection
Agency in December of 1971. A Decem-
ber 1972 submittal of a plan to the Ne-
vada Legislature by the Las Vegas Val-
ley Water District, resulted in the desig-
nation of Clark County as the responsible
entity to undertake examination of an
additional alternative, in lieu of the 9
alternatives presented in the December
1972 findings.
Basically all alternatives are regional in
scope, linking the existing communities
of Las Vegas, North Las Vegas, and
Henderson. Only the "no action" alter-
native would-re suit in perpetuation of the
three existing separate secondary effluent
discharge outfalls. At issue is the attain-
ment and maintenance of State-Federal
Water Quality Standards through limita-
tions imposed on the Wash dischargers
by EPA under the National Pollutant Dis-
charge Elimination System permit program
(NPDES), as established by Congress in
the Federal Water Pollution Control Act
Amendments of 1972.
After careful analysis, the Environmental
Protection Agency has concluded that
Alternative 10 is the alternative which
best represents the desires of the local
populace in abating pollution in Lake
Mead. In the selection of this alternative
a reclamation/reuse proposal to export
36-38 million gallons per day (mgd) of
AWT effluent to the proposed Allen Power
Plant was recommended by the applicant.
EPA will need to evaluate this proposed
reclamation/reuse intention as further in-
formation becomes available on it. There-
fore the Agency has reserved judgment on
this portion of the selected project.
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The proposed action includes the const-
ruction of a first phase 90 million gallon
per day (MGD) advanced waste treatment
(AWT) plant, a collection system from the
four existing secondary treatment plants
to the AWT Plant, a pilot desalination
and pilot ground water recharge program
of 1.0/mgd, and discharge to Las Vegas
Wash through a single outfall. Return
flow will benefit an in-valley irrigation
system and the crediting of return flows
reaching Lake Mead. Primarily, this
action is confined to Clark County, Ne-
vada and the downstream remainder of
the Lower Colorado River.
3. Impacts of the Proposed
Alternative Actions.
Of the ten alternatives proposed,
four alternatives were considered as
viable for economic and engineering
reasons in meeting the project objec-
tive, the abatement of pollution in
Lake Mead. Alternative 9, no action,
was not among them.
The primary impact of each viable al-
ternative considered varies. Normal
construction impacts can be anticipated
with each, with all alternatives empha-
sizing disposal with a Wash maintenance
discharge. Vegetative and wildlife habi-
tats will be impacted differently due to
the difference in the quantity and quality
of flow from each alternative. Each viable
alternative will result in commitment of
land for facilities, with alternatives 2 and
7 setting aside large tracts of land for
evaporation ponds, and all alternatives
will, no doubt, change the use of land.
Each alternative will result in an increase
in the use of energy. Each alternative
represents a major commitment of finan-
cial resources. Air quality will be de-
graded if a proposed power plant is ac-
comodated with AWT or secondary ef-
fluent.
Secondary impacts in the form of increased
population growth and urbanization will
occur through capacity accommodated in
all of the Alternatives. Increased re-
source consumption, whether it be from
per capita, commercial, or industrial
sources will affect resource exploitation.
All alternatives would accommodate a- .
proposed power plant with either AWT or
secondary effluent for cooling purposes.
The accommodation of this power plant
could affect future power development
projects for the Los Angeles Metropolitan
area and would initiate strip mining of
coal in Southern Utah, along with atten-
dant air and water pollution problems
arising from both actions. A system of
crediting return flows to Lake Mead
from Abatement Project discharges would
compensate for Southern Nevada Water
Project withdrawals from the Colorado
River system as adjudicated to Nevada.
Each viable alternative will result in the
abatement of pollution in Lake Mead which
has perpetuated itself due to long over-
due remedial action.
II
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4. Alternatives Considered.
Ten alternatives were considered, with
four being considered economically and
engineeringly capable of satisfying the
environmental objective of the recognized
pollution problem, "no action" not being
one of those alternatives. Alternatives
considered further in the statement for
their environmental impact are: Alter-
native 2-Complete Treatment, Alter-
native 3-AWT and Return to Lake Mead,
Alternative 7-Combination Alternative
and, Alternative 10-Amended Combination
Alternative.
5. Dates Available to CEQ
and the Public:
6. Distribution List attached.
FEDERAL AGENCIES
Environmental Protection Agency, Washington, DC
Office of Federal Activities
Office of Public Affairs
Office of Water Programs, Planning & Interagency
Program Division
Congressional Affairs Division
Office of Congressional & Intergovernmental
Relations, Region IX
Pacific Southwest Inter-Agency Committee
c/o Deputy Regional Engineer
Federal Power Commission
555 Battery Street, Room 415
San Francisco CA 94111
Soil Conservation Service
308 Post Office Building
Post Office Box 4850
Reno NV 89505
District Conservationist
Soil Conservation Service
Post Office Box 16019
Las Vegas NV 89101
U.S. Forest Service
324 - 25th Street
Ogden UT 84401
District Engineer
U.S. Army Engineer District,
Los Angeles
300 North Los Angeles Street
Post Office Box 2711
Los Angeles CA 90053
International Boundary and
Water Commission
United States and Mexico
818 Southwest Center
300 Main Drive
El Paso TX 79950
Federal Co-Chairman
Four Corners Regional Commission
Department of Commerce Building
14th St. between E and Constitution Ave., NW
Room 1898C
Washington DC 20230
Regional Director
Public Health Service
Federal Office Building
50 Fulton Street
San Francisco CA 94102
III
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Regional Administrator
U.S. Department of Housing and
Urban Development
One Embracadero Center, Suite 1600
San Francisco CA 94111
Assistant Secretary, Program Policy
Attn: Office of Environmental
Project Review
Department of the Interior
Washington DC 20240
National Park Service
601 Nevada Highway
Boulder City NV 89109
U.S. Fish and Wildlife Service
Post Office Box 16000
Federal Station -
Las Vegas NV 89101
Regional Director
U.S. Bureau of Reclamation
Post Office Box 427
Boulder City NV 89005
Area Director
Bureau of Indian Affairs
124 West Thomas Road
Post Office Box 7007
Phoenix AZ 85011
Bureau of Land Management
8217 Federal Building
Post Office Box 11505
Salt Lake City UT 84111
Regional Director
Bureau of Outdoor Recreation
Box 36062
450 Golden Gate Avenue
San Francisco CA 94102
IV
Chief, Intermountain Field
Operation Center
Bureau of Mines
Denver Federal Center, Building 20
Denver CO 80225
U.S. Geological Survey
229 Federal Building
705 North Plaza Street
Carson City NV 89701
Director, Center for Water
Resources Research
Desert Research Institute
University of Nevada System
Reno NV 89507
U.S. Department of Transportation.
450 Golden Gate Avenue
San Francisco CA 94102
Federal Power Commission
U.S. Customs House
555 Battery Street
San Francisco CA 94111
Council on Environmental Quality
722 Jackson Place, NW
Washington DC 20006
STATE AGENCIES
Nevada State Department of Conservation
and Natural Resources
Nye Building
Carson City NV 89701
Nevada Environmental Commission
201 South Fall Street
Carson City NV 89701
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State Engineer
Division of Water Resources
201 South Fall Street
Carson City NV 89701
Nevada Department of Fish & Game
Box 10678
Reno NV 89510
Mr. John Donaldson
Department of Fish & Game
Region 3 Supervisor
4747 West Vegas Drive
Las Vegas NV 89107
California State Water Resources
Control Board
1416 Ninth Street
Sacramento CA 95814
Colorado River Board
217 West First Street
Los Angeles CA 90012
Colorado River Basin RWQCB
81-715 Highway 111 (P.O. Drawer 1)
Indio CA 92201
LEGISLATORS
Mr. Wendell McCurry
Bureau of Environmental Health
201 South Fall Street
Carson City NV 89701
Mr. Bruce Arkell
State Planning Coordinator
Governor's Office
Carson City NV 89701
Administrator
Colorado River Commission
Post Office Box 1748
Las Vegas NV 89101
C. C. Tabor, Chairman
Arizona Water Quality Control Council
Route 1, Box 19
Wellton AZ 85356
Arizona State Department
of Health Services
1740 West Adams Street
Phoenix AZ 85007
Honorable Alan Bible
U.S. Senate
Room 145 OSOB
Washington DC 20510
Honorable Howard W. Cannon
U.S. Senate
Room 259 OSOB
Washington DC 20510
Honorable Mike O'Callaghan
Governor, State of Nevada
Executive Chambers, State Capitol
Carson City NV 89701
Honorable Jack Williams
Governor, State of Arizona
State House
Phoenix AZ 85007
Honorable Ronald Reagan
Governor, State of California
State Capitol, First Floor
Sacramento CA 95814
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Honorable David Towel1
U.S. House of Representatives
Longworth House Office Building
Room 1206
Washington DC 20515
Senator B. Mahlon Brown
60 Country Club Lane
Las Vegas NV 89109
Senator Lee E. Walker
1729 Arrowhead
North Las Vegas NV 89030
Senator John P. Foley
801 Pyramid Drive
Las Vegas NV 89108
Senator Chic Hecht
47 Country Club Lane
Las Vegas NV 89109
Senator Joe Neal
304 Lance Avenue
North Las Vegas NV
89030
Senator Melvin D. Close, Jr.
3838 Delaware Lane
Las Vegas NV 89109
Senator Eugene V. Echols
2908 Magnet Street
North Las Vegas NV 89030
Senator Helen Herr
4620 Meredith Avenue
Las Vegas NV 89121
Senator Richard H. Bryan
3680 Mountcrest Drive
Las Vegas NV 89121
Senator James I. Gibson
806 Park Lane
Henderson NV 89015
Senator Floyd R. Lamb
360 East Desert Inn Road
Las Vegas NV 89109
Assemblyman Darrell H.
5309 Masters Avenue
Las Vegas NV 89122
Dreyer
Assemblyman Marion D. Bennett
1911 Goldhill Avenue
Las Vegas NV 89106
Assemblyman Robert Craddock
6090 East Lake Mead Blvd.
Las Vegas NV 89110
Assemblyman Daniel Demers
231 Edelweiss Place
Mt. Charleston
Las Vegas NV 89100
Assemblyman Zelvin Lowman
1246 Cashman Drive
Las Vegas NV 89102
Assemblywoman Imogene E,
3511 Pueblo Way
Las Vegas NV 89109
Ford
VI
Assemblyman Douglas Bremner
821 Fairway Drive
Las Vegas NV 89107
Assemblyman Cranford Crawford
2215 Matheson Street
North Las Vegas NV 89030
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Assemblyman John Vergiels
490 Calcaterra Circle
Las Vegas NV 89109
Assemblyman Keith Ashworth
295 Ashworth Circle
Las Vegas NV 89107
Assemblyman Paul May, Jr.
3309 Wright Avenue
North Las Vegas NV 89030
Assemblyman James Smalley
63 Wyoming Avenue
Henderson NV 89015
Assemblyman James J. Banner
2223 Poplar Avenue
Las Vegas NV 89101
Assemblyman Robert Robinson
3504 Pioneer Circle
Las Vegas NV 89107
Assemblywoman Eileen Brookman
1900 Cochran
Las Vegas NV 89105
Assemblyman Robert Smith
1245 North Boulder Highway
Henderson NV 89015
Assemblyman Thomas Hickey
805 Glendale. Avenue
North Las Vegas NV 89030
Assemblyman Darrell W. Huff
5708 Idle Avenue
Las Vegas NV 89107
Assemblyman James N. Ullom
4309 Greenhill Drive
Las Vegas NV 89121
Assemblyman Richard McNeel
1824 Renada Circle
North Las Vegas NV 89030
Assemblyman Jack Schofield
1308 South Sixth Street
Las Vegas NV 89101
OTHERS
Clark County Waste Water
Management Agency
200 East Carson Avenue
Las Vegas NV 89101
Sewage and Waste Water Advisory Committee
c/o Clark County Waste Water Management
Agency
200 East Carson Avenue
Las Vegas NV 89101
The Honorable O. K. Gragson, Mayor
City of Las Vegas
400 East Stewart
Las Vegas NV 89101
The Honorable C. R. Cleland, Mayor
City of North Las Vegas
Post Office Box 4086
North Las Vegas NV 89030
VII
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The Honorable Cruz Olague, Mayor
City of Henderson
243 Water Street
Henderson NV 89015
The Honorable Kenneth Andree, Mayor
City of Boulder City
Post Office Box 367
Boulder City NV 89005
Mr. Bob Jones
Jones & Stokes Assoc., Inc.
455 Capitol Mall, Suite 835
Sacramento CA 95814
Mr. Curt Spencer
VTN
555 Capitol Mall
Sacramento CA 95814
Mr. Al Schmidt
VTN
2209 Paradise Road
Las Vegas NV 89015
Mr. Dave Griffith
Nevada Environmental Consultants
1209 South Commerce
Las Vegas NV 89106
Mr. Bill Knoph
Walnut Creek Plaza, Suite 750
1990 N. California Blvd.
Walnut Creek CA 94596
Mr. James Saucerman
VTN Consolidated, Inc.
2301 Campus Drive
Irvine CA 92664
VIII
Dr. Arden Gaufin
University of Utah
1400 E. 2nd South
Salt Lake City UT 84102
American Association of University
Women
c/o Mrs. Ernest Phillips
321 Pinecliff Drive
Las Vegas NV 89128
Southern California Edison Co.
2244 Walnut Grove Avenue
Rosemeade CA 91770
Robert J. McNutt
Post Office Box 539
Las Vegas NV 89101
Vernon Bostick
5805 Churchill Street
Las Vegas NV 89107
League of Women Voters
1730 M Street, NW
Washington DC 20036
Dr. Otto Ravenholt
Chief Health Officer
Clark County District Health Department
625 Shadow Lane
Las Vegas NV 89106
Mr. Dave Causey
Urban Action Commi.ttee
200 East Carson Avenue
Las Vegas NV 89101
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C. S. Lawson
Clark County Representative
Lahontan Audobon Society
509 Altamira Road
Las Vegas NV 89109
John McComb, Southwest Representative
Sierra Club
2014 E. Broadway, No. 212
Tucson AZ 85719
Mr. Harvey 0. Banks
#3 Kittie Lane
Belmont CA 94002
Mr. Ken O'Connell
Chamber of Commerce
2301 East Sahara Avenue
Las Vegas NV 89105
Ms. Glade Koch
237 Greenbriar Townhouse Way
Las Vegas NV 89121
Nevada Open Space Council
c/o Ms. Mary Kozlowski
709 Mallard Street
Las Vegas NV 89107
Mr. Jay Moore
1122 Pawnee
Henderson NV
89015
Mr. Harry Allen
Nevada Power Company
Post Office Box 230
Las Vegas NV 89101
Mr. Joe Monscuitz, Manager
Southern Nevada Water System
243 Lakeshore Road
Boulder City NV 89005
Dr. Jack E. McKee
CDM, Inc.
283 South Lake Avenue
Suite 215
Pasadena CA 91101
Mr. Nicholas G. Smith
Burraus, Smith & Co.
1003 Kearns Building
Salt Lake City UT 84101
Tudor Engineering Co,
110 West "C" Street
San Diego CA 92101
Mr. Walt Casey
Walt Casey Water Cond,
2661 Western
Las Vegas NV 89102
Ms. Li2 Vlaming
3170 Westheld Road
Las Vegas NV 89102
Dr. James E. Deacon
Biology Department
University of Nevada
4505 Maryland Parkway
Las Vegas NV 89154
Mr. Carl Blake
Titanium Metals, Inc.
Post Office Box .2128
Henderson NV 89015
IX
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The Las Vegas Valley has experienced
a phenomenal growth in the past 40 years.
With the construction of Hoover Dam in
the 30's, the foundation was laid for the
beginning of a spiraling economic growth
that is still being realized. With the ad-
vent of Nevada's quick-divorce machinery
and the legalization of most type's of gamb-
ling, a life style unique to that of any state
in the United States boomed after World
War II as casinos began to pock the pristine
desert landscape. The valley population has
increased from 122,957 people in I960 to
an estimated 316, 725 in 1973. Estimates
of population by the year 2000 range from
a low of 500, 000 people to a high.of
1, 500, 000 people. For planning pur-
oosesthis impact statement has adopted the
Clark County Regional Planning Council's
year 2000 medium population projection
of 700, 000 people for Las Vegas Valley.
The increased automobile traffic into and
within the area, and the construction of
in-valley fossil fueled power plants soon
degraded the clarity of the desert skies.
By the end of the sixties, the new decade
brought a national awakening of an environ-
mental conscience.
Municipal and industrial waste waters
rich in nitrogen, phosphorus and dissolved
solids are discharged into Las Vegas
Wash. These discharges, along with highly
saline subsurface flows, are polluting Lake
Mead and downstream Colorado River.
The principal effects that have resulted
are increased algal mats that die-off,
lowering dissolved oxygen, causing odors,
and reducing the potability and useability
of the water due to poor taste, bacterial
contamination and/or salt concentration.
As this snowballing phonomena of urban
growth boomed, the quality of life im-
proved, yet began to take its toll on the
quality of the environment. After a history
of damming, diverting, and dividing up
the Colorado River, man-made tributaries
of nutrients, toxins, solids, and salts
began to replace the once pristine streams.
Major efforts toward developing a pollution
abatement program in the Las Vegas Wash/
Lake Mead area were initiated in 1967.
Through the efforts of citizens within the
Las Vegas Valley, and the concern of
Federal, State, and local agencies to check
any further pollution of water resources,
a commitment among them was joined to
XI
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define and determine the future environ-
mental goals and objectives of such an
undertaking.
Repeated investigations and reports failed
to produce a unified strategy for abate-
ment of pollution. In December of 1971,
a conference was called by the U.S.
Environmental Protection Agency to
discuss with all responsible agencies and
in-valley dischargers a pending 180-day
enforcement action against them by EPA
for failing to do so. In 1971, the Nevada
Legislature designated the Las Vegas Val-
ley Water District (LVWD) as the agency
responsible for developing a plan to abate
the pollution caused by municipal waste
water flows in Las 'Vegas Wash. Industry
would provide their own means of meeting
discharge requirements set by the Envi-
ronmental Protection Agency.
The plan, which outlined a program of
exporting polluted waters to the Dry Lake
area, was completed in December of 1972,
The 1973 Nevada State Legislature,
through it's passage of Senate Bill 288
(NRS 790) approved the final written re-
port of the Las Vegas Valley Water Dis-
trict. This recommended plan of export
however was unacceptable to EPA since
the return to the system of high quality
return flows was considered more bene-
ficial than disposal by export. The Legis-
lature reflected this concern by recog-
nizing that there may be further alterna-
tive solutions to the pollution abatement
problem, and in Senate Bill 288 trans-
ferred the responsibility for developing
a solution of the problem) to the Clark
XII
County Board of County Commissioners.
In July of 1974, the Board of County Com-
missioners submitted to the Environmen-
tal Protection Agency 10 alternatives of
abatement action in their Facilities Plan
- Annex A and Addendum to the Environ-
mental Assessment - Annex B for the Las
Vegas Wash Bay Pollution Project. Prior
to these latest submittals, numerous sup-
porting documents were used in this effort.
The 1972 Environmental Assessment pre-
pared for the Las Vegas Valley Water
District, was part of the 1972 submittal
to the State Legislature. The assessment
evaluated 9 possible actions formulated
to accomplish waste water management.
in Las Vegas Valley. Six of the possible
actions were presented in a "Phase III"
Engineering Project Report also prepared
for the LVWD. The seventh alternative,
which was selected by the LVWD, com-
bined several of the "Phase III" alter-
natives. . The eighth alternative was sug-
gested at a public meeting and the ninth,
"no action" alternative was included to
comply with The National Environmental
Policy Act of 1969.
In accordance with directives of Senate
Bill 288, the Board of County Commis-
sioners considered a tenth alternative
in their July 1974, Annex A and Annex
B.
Therefore the purpose of this environ-
mental impact statement is to now evaluate
the environmental implications of meeting
the approved Federal-State water quality
standards through the alternatives pro-
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posed and any permit issued by EPA in
compliance with the National Pollution
Discharge Elimination System to regulate
municipal discharges in Las Vegas Wash.
The alternative recommended by the ap-
plicant as economically and engineeringly
viable will be evaluated. The Environ-
mental Quality Objectives, supported by
the Board of County Commissioners, as
the guiding criteria for viable alternatives
selection in their Facilities Plan and En-
vironmental Addendum are:
1. Attain a clean desert environment.
2. Maintain Las Vegas Wash as a per-
manent riparian environment.
3. Develop additional greenbelts by in-
valley irrigation.
4. Optimize the use of water.
5. Protection of the environment
from the adverse impact of con-
struction.
The environmental quality objectives pro-
viding guidance to EPA in this environ-
mental impact statement for the selection
of the most environmentally viable al-
ternative are those specified in Section
101 of the Federal Water Pollution Control
Act Amendments of 1972 (FWPCA) and
Section 101 of the Clean Air Act of 1970.
This statement shall conform to the pro-
visions of Section 102 (c) of the National
Environmental Policy Act (NEPA) of 1969;
the April 23, 1971 Guidelines for the
preparation of Environmental Impact State-
ments published in the Federal Register
by the Council on Environmental Quality
(36 FR 7724) and; the July 17, 1974
Notice of Proposed Rulemaking by the U.S.
Environmental Protection Agency as pub-
lished in the Federal Register concerning
the Preparation of Environmental Impact
Statements (39 FR 138). The Environmen-
tal Protection Agency's Notice of Proposed
Rulemaking is attached as Appendix A.
This Environmental Impact Statement is
written to indicate a process by which a
decision has been made and the rational
behind making that decision. Chapter 7
of the Statement discusses the selected
alternative and summarizes the reasons
for its selection. In the process of analy-
sis undertaken by the Environmental Pro-
tection Agency, the selection of the plan
deemed most feasible was the final step,
and occurred only after careful and criti-
cal review of all the alternatives including
the alternative recommended to EPA by
the Board of County Commissioners.
The Environmental Protection Agency
wishes to gratefully acknowledge the
assistance provided by the many contri-
butors in this on-going process. The
numerous interested organizations, in-
dividuals, and public agencies whose
efforts through the public have provided
direction in the preparation of this draft
statement are greatly appreciated. Of
note are the efforts of the Board of
County Commissioners, the Clark County
Waste Water Management Agency, the
Sewage and Waste Water Advisory Com-
XIII
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mittee (SWAG) of Clark County, and the
Las Vegas Valley Water District and
their engineering and environmental
consultants. Much of the information
assembled and presented in
previous engineering project reports
and environmental impact assessments
by those previously mentioned, was
either edited or transcribed verbatim.
Communications with the staffs of NECON,
VTN, Jones and Stokes Associated, In-
corporated, and the Clark County Waste
Water Management Agency has facilitated
the expeditious resolution of this signi-
ficant environmental action, the benefits
of which will be felt for many years to
•come.
Finally, we wish to acknowledge the efforts
of the State of Nevada through it1 s State
Legislature and executive agencies in the
furtherance of statewide programs to
improve the quality of the nation's waters.
ENVIRONMENTAL CONSTRAINTS
As part of any ecological system, man has
to contend with limitations in his adapta-
bility as a biological organism. Place him
in a barren, extremely arid, hot water -
short desert environment . . . and the pic-
ture these "Environmental Constraints" pre.
sent to planners is one of neverending at-
tempts at the resolution of some very fun-
damental necessities of life.
Simply stated, the availability of water,
shelter from the sun's heat, and fuel must
first be satisfied before man is capable- of
carrying on any consideration of being there
in the desert for any sustained period of
time.
Las Vegas however, runs on a very unique
statement of the American phenomena. As
was described in the Las Vegas Report
1974 published by the Greater Las Vegas
Chamber of Commerce, "the city where
. . . .money flows freely was founded and
has prospered on the carefree individual,
millions of them, all seeking refuge from
doldrums of day-in and day-out living".
Therefore the human organism is provided
for so that it can pursue this unique refuge.
The ground rules for making the neces-
sary environmental decisions in this in-
stance have been spelled out by Congress.
The National Environmental Policy Act
of 1969 was enacted at the end of a pheno-
menal decade of American Growth, aware-
ness, and social upheaval that expounded
a national ethic heralding the need to
evaluate what had been going on. The
national government responded with a
major reformation in the emphasis of se-
veral federal programs and agencies by
Executive Order coupled with congres-
sional enactment of the Clean Air Act
of 1970 and the Federal Water Pollution
Control Act Amendments of 1972, mandat-.
ing the Environmental Protection Agency
to administer and regulate the cleaning
up of the nation's air and water and keep-
ing them clean.
Water, whether it be it's quality or abun-
dance, is by far the most limiting con-
XIV
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straint in this analysis. What it pro-
vides, as far as sustaining the Las Vegas
community in the style it is accustomed
to, is life. From this Agency's pers-
pective if economic viability and population
growth are to continue, water quality
degradation of existing and future potable
water supplies from salt, nutrients, and
toxins must be abated. The capability of
the emerging in-valley megalopolis to
continue to assimilate its excesses, its
wastes, back into the environment is by
far the leading action of this Agency.
Air quality is an equally significant res-
ponsibility of this Agency and is as equally
well defined as a resource as is water
quality. Gases and particulates are
translated into clarity, tolerance, and
irritant standards by Federal and State
law. Human life-style and the kind of
urban residential, commercial, and in-
dustrial growth it spawns inversely im-
pacts concentrations of these gases and
particulates. In this instance, we again
must speak in terms of the assimilative
capability of man's environment to meet
this air quality constraint.
By providing this capability to assimilate
wastes, Las Vegas will be establishing
many new dependencies and interrelation-
ships with a much larger environment.
This larger environment must be capable
of assimilating Las Vegas.
XV
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SUMMARY
INTRODUCTION
ENVIRONMENTAL CONSTRAINTS
TABLE OF CONTENTS
CHAPTER 1 THE ENVIRONMENT
LOCATION
CLIMATE
GEOLOGY
SOILS
WATER RESOURCES
WATER QUALITY
WATER RIGHTS
AIR QUALITY
VEGETATION
WILDLIFE AND FISH
HARE AND ENDANGERED SPECIES
HISTORICAL BACKGROUND
POPULATION
LAND USE
HOUSTNG
TRANSPORTATION
EMPLOYMENT
HISTORICAL SITES
RECREATION
UTILITIES
WATER USE
WASTE^WATER -FLOWS
EXISTING SANITARY FACILITIES
CHAPTER B. SELECTION OF ALTERNATIVES
DESCRIPTION OF ALTERNATIVES
SCREENING OF ALTERNATIVES
ENERGY CONSUMPTION OF THE VIABLE ALTERNATIVES
RELATED CONSTRUCTION
EVALUATION OF THE VIABLE ALTERNATIVES
THE NPDES PERMIT PROGRAM
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128
132
142
142
159
173
173
177
180
XVI
-------
CHAPTER 3 ENVIRONMENTAL IMPACTS 184
PRIMARY IMPACTS 184
Impacts of Construction 184
Impacts of the Project Features in Common 188
Water Quality 200
Water Quantity 203
Vegetation and Wildlife 205
Impacts of No -Action 210
SECONDARY IMPACTS 211
Economic Implications 211
Growth Accomodations 212
The Environmental Impacts of the 213
Allen Power Generating Facility
Implications on Regional Air Quality 215
Water Quality Implications 218
Water Quantity Impacts 219
Fish and Wildlife Impacts 220
CHAPTER a ADVERSE IMPACTS WHICH 221
CANNOT BE
PRIMARY IMPACTS 221
SECONDARY IMPACTS 222
CHAPTER 5 RELATIONSHIP BETWEEN 226
LOCAL SHORT TERM USES
VERSUS LONG TERM PRODUCTIVITY
CHAPTER 6 IRREVERSIBLE AND IRRETRIEVABLE 230
COMMITMENT OF RESOURCES
CHAPTER "7 SELECTED PROJECT 234
ILK3QRAPHY 238
XVII
-------
APPENDICES
A Environmental Protection Agency, Preperation 1
of Environmental Impact Statements: Notice
of Proposed Rulemaking, Federal Register
July 17, 1974
B Flora and Fauna H
C October 24, 1973 and April 9, 1974 revisions 42
to the Water Pollution Control Regulations
D Nevada Air Quality Regulations 50
E 1973 Particulate and SO2 Emission Percentages 56
F 1973 CO and HC Emission Percentages 57
G 1973 NOX Emission Percentages 58
H Dr. Thome Butler's comments 59
XVIII
-------
^ \
XV '.
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The present environment will be the stan-
dard against which the future environments
accommodated by any of the proposed al-
ternative actions will be contrasted. This
reference point provides the foundation
from which the beneficial arid detrimental
effects of construction and operation of
each project alternative are evaluated.
In the course of making environmental
evaluations, it has been advantageous to
divide the present environment into the
following descriptive categories:
(1) The regional environment, including
the Las Vegas Basin, Las Vegas Bay
and the Lower Colorado River System.
(2) Several area environments, encom-
passing Dry Lake, Eldorado, Jean Lake
and Hidden Valleys and the Las Vegas
Valley/Wash drainage.
(3) Specific site environments, consis-
ting of and relating to the site-specific
locations of the proposed project facili-
ties and areas of project impact.
LOCATION
Regional Locations
The regional environment, including the
Las Vegas Basin, Las Vegas Bay as'it
relates to the Las Vegas Wash, and the
Lower Colorado River System, is located
at the junction of the States of Nevada,
Arizona and California. The combined
areas are either a part of Clark County
or a part of the border between the
above-mentioned States.
To the southwest of the Las Vegas Basin
are the lofty Spring Mountains which
reach an elevation of nearly 12, 000 feet.
The northeast has several somewhat
lower mountain ranges, chiefly, the
Sheep and Las Vegas Ranges. Indian
Spring Valley, that forms the northern
part of the project area, is bordered
by a series of spurs from the north-
trending Pintwater and Desert Ranges
and by the southern end of the Spotted
Range. The McCullough Range and
Eldorado Mountains are to the south of
the area of concern while the Muddy
Mountains and Frenchman Mountain
form a part of the eastern border.
H
-------
Las Vegas Bay is an arm-of the Boulder
Basin area of Lake Mead, Las Vegas
Wash enters the Bay at its western
extremity. As the immediate recipient
of its flows, the chemical, physical and
biological conditions of the Bay are di-
rectly influenced by the outflow from
the Las Vegas Wash.
The Colorado River begins at the Con-
tinental Divide near Mount Richthofen,
a peak with an elevation of 13, 000 feet.
It flows in a generally southwesterly
direction from its headwaters in north
central Colorado for about 1400 miles
to the Gulf of California. The Colorado
Basin is composed of rugged mountains,
high plateaus, deep canyons, deserts
and plains, covering an area of 244, 000
square miles (approximately 1/12 the
area of the entire continental United
States). The Colorado River Basin
includes parts of Arizona, California,
Colorado, Nevada, New Mexico, Utah
and Wyoming.
Lee Ferry, Arizona, located approxi-
mately 17 miles downstream of Glen
Canyon Dam near the confluence of
the Paria River, was established in the
Colorado River Compact of 1922 as the
point in which the Colorado River Basin
is divided into the "Upper Basin" and
"Lower Basin" for legal, political,
institutional and hydrologic purposes.
The Lower Basin encompasses about
55% ol the drainage area ot the Colo-
rado River Basin, and includes Las
Vegas Wash. After leaving Glen Can-
yon Dam, the Colorado River flows into
the.Lower Basin and passes through the
Grand Canyon into Lake Mead. This
locates the Colorado River system east
of the study area. Hoover Dam restricts
Colorado River flow to form Lake Mead,
which at one time was the largest reser-
voir in the world.
From Hoover Dam to the Mexican Border,
the River travels 326 miles, nearly 40%
of which is contained within reservoirs.
The reach below Lake Mead and Hoover
Dam includes Davis Dam, Parker Dam
and Imperial Dam which impound Lake
Mojave, Lake Havasu and Imperial
Reservoir, and provide water for major
diversions such as the Ail-American
Canal, the Gila Canal and Colorado River
Aqueduct. Minor dams within the reach
include Headgate Diversion Dam, Palo
Verde Diversion Dam and Laguna Di-
version Dam.
Area Locations
Las Vegas Valley, the most important
of the area environments, trends south-
east about 50 miles from Indian Springs
to Las Vegas Wash. The northern part
of the Valley, which extends 30 miles
from Indian Springs to Tule Spring, is
irregularly shaped and relatively narrow;
it ranges from 4 to 10 miles in width.
South of Tule Spring the Valley widens
into a rectangular-shaped basin that is
approximately 18 miles wide and 24 miles
long. The cities of Las Vegas and North
Las Vegas are in the center of this part
of the Valley, and are approximately 11
miles to the west of Lake Mead.
-------
Davis D»m
Utah
Mesquite
lunkerville
Arizona
CM
VICINITY MAP
Source: NECON
Prepared by VTN
-------
The Las Vegas Wash is the chief drainage
channel of the 1,590 square-mile Las
Vegas Valley drainage basin. The only
perennial stream in the area, it is lo-
cated east of the City of Las Vegas and
flows easterly to Lake Mead. For pur-
poses of this report the Wash begins at
the City of Las Vegas Waste-Water
Treatment Plant on Vegas Valley
Drive and ends 11 miles downstream
beyond North Shore Road where it
flows into Las Vegas Bay. The Las
Vegas Wash is the principal channel
for removal of the treated municipal
and industrial waste water for Alter-
natives 2, 3, 7 and 10.
Considering Las Vegas Valley as the
center, Dry Lake Valley is directly
northeast, Jean Lake is directly south
with Hidden Valley and Eldorado Valley
respectively, directly east of Jean Lake.
Site Locations
The site locations considered to be occu-
pied by project facilities and areas of pro-
ject impact include:
(1) Ground-water recharge well field
and Pilot desalination plant,
(2) Waste-water collection system,
Treatment plant, Deep disposal well
field areas, and Sludge disposal site,
(3) Las Vegas Valley lands to be
irrigated,
(4) Dry Lake Valley,
(5) Eldorado Valley,
(6) Jean Lake,
(7) Hidden Valley.
Ground-Water Recharge Well Field
and Pilot Desalination Plant
Alternatives Nos. 1 and 10 propose
the recharge of desalinized waste water
or a blend of advanced waste treatment
(AWT) and desalt water into the middle
aquifer of the ground-water basin. The
injection*well field site is to be located
to the west side of the City of Las Vegas.
Also located in the same area will be a
Pilot Desalination Plant as part of Alter-
native 10. It will occupy a gross land
area of approximately two acres on a
site owned by the Las Vegas Valley
Water District.
Waste-water Collection System, Treat-
ment Plant. Deep Disposal Well Field
Areas, and Sludge Disposal Site
The collection system, treatment plant,
deep well disposal field and sludge dis-
posal site are all located to the eastern
-------
CRAIG ROAD
ALEXANDER RQAD
1 MGD
PILOT GROUNDWATER RECHARGE
SITE LOCATION
SCALE IN MILES
OPERATIONAL WELLS OF THE LAS VEGAS VALLEY WATER DISTRICT
PROPOSED I MGD PILOT DESALINATION PLANT
PROPOSED AREA FOR PILOT RECHARGE WELL
— _^_— PROPOSED IN-VALLEY IRRIGATION PIPELINE FROM AWT
lv.t......... DESALINATION PLANT PRODUCT WATER LINE
-------
-WyMHMA
Wl
>*•
I
3
*>
AWT PLANT
AND
COLLECTION PIPELINES
EXISTING SECONDARY WW f
-Sunwt Rood
i UNDER CONSTRUCTION BY HENDERSON
-------
side of the City of Las Vegas.
The collection system begins south of
Vegas Valley Road, following the border
of agricultural lands to the Clark County
plant discharge ditch. For Alternatives
1, 4, 6, 7, and 8 effluent will be col-
lected from Henderson sewage treatment
facilities via a subsurface pipe. For
Alternatives 2, 3 and 5, effluent would
be conveyed from the Clark County plant
to the regulating reservoir via an open
channel. The collection system for
Alternative 10 will consist of three pipe-
lines - one from each of the existing
secondary waste-water treatment plants,
Clark County, the City of Las Vegas and
the City of Henderson. These secondary
effluent lines will join at the influent
surge pond located adjacent to the Clark
County plant.
The sites for the waste-water regulating
reservoir and treatment facilities for
Alternatives 1, 4, 6, 7, and 10 and
deep disposal well field for Alternative 8
are located southeast of the Clark County
Sanitation District plant. The site for
the waste-water regulating reservoir and
treatment facilities for Alternatives 2, 3,
and 5 is located west of the BMI waste
disposal ponds and directly between Las
Vegas Stadium and an existing gravel
works. The proposed location of the
Advanced Waste-water Treatment facili-
ties of Alternatives 2, 3, and 10 is an
80 acre pasture to the south and east of
the existing Clark County Sanitation Dis-
trict waste-water treatment plant. Both
the prototype AWT facility site identified
for Alternative 7 and the AWT plant site
identified in Alternatives 1 and 8 are
located some three miles north of the
aforementioned AWT facility for Alter-
natives 2, 3, and 10.
Sludge from the proposed Clark County
Advanced Waste-water Treatment plant
will be transported by pipeline from the
plant facilities to a 48 acre evaporation
site approximately 1/4 mile to the east
of the Clark County Sanitation District
Plant.
Las Vegas Valley Lands to be Irrigated
Five of the proposed alternatives (1, 2,
3, 8 and 10) include a system of using
AWT water other than the secondary
treated sewage proposed for use in
Alternatives 4, 5, 6 and 7 for the
irrigation of parks, golf courses and
greenbelt areas in the Las Vegas
Valley. This system consists of 18
miles of buried pipelines, four open,
concrete one-acre reservoirs, and three
pump stations. The irrigation program
will be developed in four stages. Stage 1
will consist of approximately 26.4 miles
of 4-30 inch pipeline, two lift stations
and two storage reservoirs. Stage 4
will have 33. 5 miles of 4-24 inch pipe-
line, two lift stations and two reservoirs.
Dry Lake Valley
Dry Lake Valley is proposed as a site to
8
-------
REJECT SOLIDS PIPELINES
FROM AWT PLANT
TO DRYING BEDS
AWT PLANT
£' REJECT SOLIDS DRYING BEDS
-------
ElKNOm ROAD
IN-VALLEY IRRIGATION SYSTEM
CENTENNIAL P»RK*H
L_
''
l~ • • ;
*
J
* j
-"" -
/ rfef^
£.:.•-. \. —
STAGE I
AREAS TO BE IRRI6ATED
Sumit Perk
LVVWD Ground!(ChorlntOTi Hlightil
3)- UNLV Campui
4J - Lai Viaoi Country Club
Municipal Goll Cauru
Dunn Golf Count
7) Sahoro-Ntvado Soil Count
- Dtitrt Inn Golf Count
9) - Tropioono toll Couni
JOJ - LottMi Pork
Count) Horn Anna
,12) - Palm Volliy Viii khmoriol Park
Sum of Small Parks and Srttnbiili
Total Stogi I
STAGE
.54) - Black Mountain Goll C.uri.
- Lai Viga* Stadium
- Community Pork
Sum ol Small Parkt
Total SlootH
CROSS ACREA6E
325.0
220.0
200.0
I 60 .0
144.0
1 40.0
130.0
100.0
80.0
99.4
90.0
40.0
1,895.8
136.0
60.0
40.0
82.4
318.4
STAGE II
(49- NLV RtgioiMl Pork
- Craig Ranch Goll Couru
- Natun Park
- Frttdon Park
- Caihmon Find
- Chiyinnt Park
Sum ol Small Parki and Grunbilti
Total Stogi ffl
_STA6E H
- Ntlln Goll Count
• Sunrni Mountain Rtcnolional Park
Sun of Swill Park.
Total Stogi U
TOTAL IRRIGATION AREA
860.0
160.0
I 16.8
73.0
.SO.O
40.0
347.1
1,646.9
120.0
100.0
6.0
226.0
LEGEND
Stage I Main
Stagt I Lateral
Stage II Main
Stage III Main
- Stage III Lateral
- Stage IV Lateral
—— - Export line to Allen Power Plant
Pumping Station
• Reservoir
S County AWT Plant
* Small Land Area
A Pilot Desalt Plant
STAGED
IN-VALLEY
IRRIGATION
SYSTEM
10
-------
evaporate exported brine and/or secon-
dary effluent as part of Alternatives
1, 2, 4, and 7. The Valley is 27 miles
northeast of Las Vegas on the Salt Lake
City highway between the Arrow Canyon
and Dry Lake Ranges.
Eldorado Valley
Alternative No. 5 proposes export of
effluent to Eldorado Valley for agricul-
tural irrigation and/or evaporation.
This Valley is directly east of Jean
Lake, 28 miles southeast of Las Vegas,
and to the south of Boulder City between
the McCullough Range and Eldorado
Mountains.
Jean Lake
The third and fourth sites under consider-
ation for export are Jean Lake and Hidden
Valley. These two Valleys are consi-
dered in Alternative 6 as a single site
and in Alternative 7 as two separate
sites.
Jean Lake is located 30 miles southwest
of Las Vegas between the Sheep Moun-
tains and McCullough Range.
Hidden Valley
Hidden Valley is directly east of Jean
Lake and directly west of Eldorado
VallSy. It is bounded on the north and
west by a low range of unnamed hills,
and on the south and east by the Mc-
Cullough Range. A low rocky pass
exists between Jean Lake and Hidden
Valley.
Refer to the figures in Chapter 2 for
the specific geographic location of these
sites.
CLIMATE
Regional Climate
The climate of the regional area ranges
from arid on the valley floor to semiarid
in the mountains. The arid climate of the
lowlands is characterized by low precipi-
tation, low humidity, and wide extremes
in daily temperature. The winters are
relatively short and mild, and the sum-
mers, long and very hot. Rainfall aver-
ages about four inches per year, but
may be highly variable. Most of the
precipitation occurs during the winter
months and in July and August. Preci-
pitation in July and August commonly
is from highly localized thunderstorms
and cloudbursts which typically are of
high intensity and short duration and
cause flash flooding with rapid runoff
and severe erosion with minimal pene-
tration of moisture into the soil. Pre-
cipitation during the winter usually is
from regional storms of low intensity
and longer duration. Evaporation rates
at lower elevations are extremely high
and probably exceed 80 inches per year.
11
-------
Relative humidity averages 28%. Strong
winds are common throughout the year
but are prevalent during the spring.
The growing season (frost free) approx-
imates 241 days. Irrigation is required
for lawns and practically all crops.
The climate at Las Vegas Bay/Lake
Mead is arid. Mean annual tempera-
ture at Las Vegas is 66°F (19°C) and
annual precipitation is less than 5 inches,
according to Weather Bureau records.
Maximum temperatures of 110°F(43°C)
are not uncommon'in July and August,
but the heat is not oppressive because
of low humidity. Average minimum
temperature in January is 30°F(-1° C).
Winds are generally light. Water-
surface temperatures at Lake Mead lag
about one month behind air temperatures
at Lake Mead and Las Vegas. Nearly
all of the difference in air temperatures
is attributable to the fact that the altitude
of Las Vegas airport is about 1,000 feet
higher than Lake Mead.
Rainfall on the lake surface, averages
less than one-half of one percent of the
inflow. Two tipping-bucket recording
rain gages are used to measure rain-
fall; they are located on Boulder Island
in Boulder Basin and on the barge in
Boulder Basin. The average of the rain-
fall recorded by the two rain gages at
Boulder Island and Boulder Basin Barge
is assumed to be representative of the
entire lake.
Wind speeds at the eight-meter level on
the barge in Boulder Basin over the Lake
are, in general, higher than wind speed at
the Las Vegas airport* The anemometer
at the airport is almost exactly eight
meters above the ground so that the
records are comparable in this res-
pect. During much of the year the
circulation is thermally induced rather
than the result of large-scale cyclonic
activity, and the local terrain has a
great influence on both wind speed and
direction. If the vapor pressure at Las
Vegas can be considered representa-
tive of unmodified air in this region,
it is apparent that the air over Lake
Mead is substantially modified during
its passage over the Lake. It is also
apparent that the vapor blanket extends
above the eight-meter level at mid-lake.
In general, the vapor pressure difference
between the two- and eight-meter levels
is less than the difference between Las
Vegas and the eight-meter level.
One of the chief characteristics of the
climate of the Lower Colorado Region
is its variety. The wide range in cli-
matic conditions is the result of large
differences in altitude, a considerable
range in latitude, and the distribution
of mountain ranges and highlands. Be-
cause of the different topographical fea-
tures and elevation variations throughout
the Region, a number of different clima-
tic classifications are present. Most of
the Region falls into a Steppe climate,
which stretches from the southeastern
corner of the Gila Subregion northwest-
ward into northwestern Arizona and the
Nevada portion-of the Region.
12
-------
Along the Colorado River, average an-
nual precipitation varies from 25 inches
or more along the North Rim of the
Grand Canyon to five inches or less
along the River below Lake Mead. The
western and southern portions of the
Subregion are characterized by mild
winters and hot summers. Summer
temperatures average in the mid-
seventies at the Grand Canyon and a
hundred plus degrees at Las Vegas.
Area Climate
conditions in this area, and causes
scattered thunder showers, occasionally
quite severe, together with higher than
average humidity. Although maximum
temperatures are much lower during
this humid period, minimum tempera-
tures are higher than usual, and many
natives consider this the most unplea-
sant weather of the year. Soil erosion,
especially near the mountains and foot-
hills surrounding the Valley, is evidence
that these summer thunder showers have
in the past, on occasion, developed into
"cloudburst" proportions.
In Las Vegas Valley, weather observa-
tions are taken at McCarran Airport,
seven miles south of downtown Las
Vegas, and about five miles southwest
and 300 feet higher than the lower por-
tions of the Valley. Since mountains
encircle the Valley, drainage winds are
usually downslope toward the center,
or lowest part of the Valley. This con-
dition also affects minimum tempera-
tures, which in lower portions of the
Valley can be from 15° to 25° colder
than recorded al the airport on clear,
calm nights.
The four seasons are well defined.
Summers are typically "desert" with
maximum temperatures usually in the
100° plus bracket. The proximity of
the mountains contributes materially
to the relatively cool summer nights,
with the majority of the minimums
being between 70° and 75°. There
is a period of about two weeks almost
every summer when warm, moist,
tropical air predominates weather
Aside from this short, humid period,
summers are not as uncomfortable as
indicated by the daytime maxima, be-
cause of the prevailing low humidity.
Winters, on the whole, are mild and
pleasant. Daytime temperatures
average near 60° with mostly clear
skies and warm sunshine. Winter min-
imum temperatures average 35°. The
spring and fall seasons are generally
considered most ideal, although rather
sharp temperature transients occur
during these months. The average
annual evaporation rate is about 72
inches.
The Sierra Nevada Mountains of Cali-
fornia and the Spring Mountains im-
mediately west of Las Vegas Valley,
the latter rising to elevations over
10, 000 feet above the valley floor, •
act as effective barriers to moisture-
laden storms moving eastward from the
Pacific Ocean. It is mainly these bar-
riers that result in a minimum of dark,
overcast and rainy days. Rainy days
13
-------
average from less than one in June to
three per month in the winter months.
Snow rarely falls in this Valley, and it
usually melts as it falls, or shortly
thereafter. The one real exception
occurred during January 1949 when 16. 7
inches of snowfall was recorded.
Climate at Eldorado, Jean Lake and
Hidden Valleys is also typical for that
described for Las Vegas Valley. The
two significant climatic factors for these
areas are the evaporation rate of 72
inches per year and the southwesterly
winds which occur most of the year.
Strong winds, associated with major
storms, usually reach this Valley from
the southwest or through the pass from
the northwest. Winds over 50 m.p. h.
are infrequent, but when they do occur,
they are probably the most provoking of
the elements experienced in the Las
Vegas Valley, because of the blowing
dust and sand associated with these
stronger winds. (U.S. Department of
Commerce, 1971).
Climate at Las Vegas Wash is the same
as that described for Las Vegas Valley.
A typical arid desert climate with low
rainfall, abundant sunshine, mild win-
ters and long, hot summers character-
izes the area. Due to the local thun-
derstorms and cloudbursts during the
summer'months, the flow in the Wash
increases by more than 30% on an aver-
age of 11 days each year.
Climate at Dry Lake is typical of that
described for Las Vegas Valley. The
two significant climatic factors for this
Valley are the high evaporation rate of
72 inches per year and the strong north-
easterly winds which blow across the
Valley, usually in August.
GEOLOGY
Regional Geology
The regional area lies within the Basin
and Range Physiographic province. The
province is characterized by desert
basins having interior drainage flanked
by mountains that generally are sparsely
covered with vegetation. The high moun-
tains usually are dissected by deep ravines
that open onto broad alluvial fans. Com-
monly, fans from adjoining canyons have
coalesced and formed a continuous allu-
vial slope along the base of the mountain
ranges. These slopes extend outward
into the valleys, where they merge with
the valley floor or extend across the
valley toward the adjacent mountain
ranges to form alluvial divides. Beyond
the toes of the fans is the valley floor.
The valley floors are usually flat and
contain one or more playas, or dry lakes,
where periodic runoff from storms
accumulates and eventually evaporates.
The surface area of the Basin is about
3000 square miles. Elevation varies
from near 500 feet at the Colorado River
to over 11, 900 feet at Charleston Peak.
14
-------
The terrain surrounding Las Vegas Bay
consists of rugged, faulted desert moun-
tains which slope steeply into rock strewn
alluvial slopes and washes. These gentler
slopes drop down to the shore of the Bay.
The shoreline of Las Vegas Bay is highly
irregular with many small coves and
inlets. There are a few beach areas but
significant erosion of the bulk of the
shoreline has not, as yet, occurred.
Las Vegas Wash is the only tributary
which enters Lake Mead in the vicinity
of the Bay.
The Lower Colorado Region lies within
two of the major physiographic provinces
of the Southwest, the Basin and Range
Province, and the Colorado Plateau
Province. The Basin and Range Pro-
vince is of importance to this study as
it occupies the southern and western
portions of the Region and is within the
drainage area of the Colorado River.
The Province is characterized by isolated
mountain blocks separated by broad allu-
vial-floored basins. The elevations of the
mountain blocks are as much as 10, 000
feet above mean sea level and usually
are between 1, 000 and 4, 000 feet above
the floors of the subjacent basins. The
elevations of these basins range from
100 feet to as much as 5, 000 feet. Most
of the valleys in the Basin and Range
Province trend north to northwest. These
alternating mountains and valleys were
produced by large-scale faulting in which
the mountain blocks were uplifted and the
basins were depressed. Subsequent to
and during faulting, the valleys were
filled with alluvial material eroded from
the mountain masses which are composed
chiefly of granite, gneiss, schist, and
quartzite. Many mountains are capped
with volcanic rocks. Along some of the
mountain fronts, the hard rocks have been
planed by erosion to gentle slopes.
During Tertiary time, the large-scale
movement along predominantly north-
west-trending faults formed the general
outlines of the Basin and Range structural
pattern. It is probable that some move-
ment on a smaller scale continues to the
present time. In many valleys, the
basement rocks are overlain by a coarse
material of generally low permeability,.
which has eroded from the nearby high-
lands. Concurrent with this sedimenta-
tion, faulting occurred and volcanic erup-
tions deposited lavas. In some areas the
basin drainages were dammed forming
lakes and playas in which fine-grained
sediments were deposited. Subsequent
erosion of the mountains caused thick
alluvial fill to be deposited in the valleys.
Volcanism continued intermittently and
lava flows, in some places, are inter-
bedded with the alluvium.
The alluvium, which represents several
stages of deposition under different en-
vironments, is the major deposit in the
structural basins and consists of lenses
of gravel, sand, clay, and silt in varying
thicknesses. Locally it may be as much
as 3, 000 feet thick. Common to the fill
in the central part of many of the valleys
are areas of considerable thicknesses of
clay. Locally, these clay beds contain
15
-------
lenses of gravel and sand. Sand and
gravel are deposited along the larger
streams and along the mountain fronts.
Channel deposits along the present drain-
ages consist of mixtures of unconsolidated
gravel, sand, and silt. These deposits
include alluvial fill that underlies the
flood plains of the present streams in
the Basin and Range province. This
alluvial fill is the major ground-water
reservoir in the Basin and Range pro-
vince. Recharge to the fill occurs near
the mountain fronts and along the stream
channels as seepage from the few peren-
nial and many intermittent streams. Only
occasionally do the main drainages carry
water their full length for more than a
few days.
The Colorado River became a through-
flowing stream in late Cenozoic time.
Downcutting by the River and its tribu-
taries resulted in deep entrenchment of
the entire system resulting in the spec-
tacular canyons. Runoff from the pla-
teaus in the Lower Colorado Region is
to the Colorado, Little Colorado, and
Virgin Rivers. The Colorado and Virgin
Rivers are perennial and all the other
streams are intermittent, except for
some short reaches.
Area Geology
Las Vegas Valley is a basin with smooth
gentle alluvial slopes bounded by numer-
ous isolated, relatively high, steeply
sloping mountain ranges which trend
north-south. The Valley may be classi-
fied in three physiographic units: the
mountains, the alluvial aprons and the
basin lowlands.
The mountains have a relief of several
thousand feet and have areas of erosion
where streams have cut (and are con-
tinuing to cut) deep ravines and canyons.
The highest peaks are in the Spring
Mountains to the west where Charleston
Peak reaches an elevation of 11, 910 feet.
The Sheep Mountains to the north are
less than 6, 000 feet above the floor of
Las Vegas Valley, which is at an ele-
vation of about 2, 000 feet. The "bed-
rock" of the area, which forms the moun-
tains and underlies the alluvial valley fill,
is composed of consolidated rocks of re-
latively low permeability. These rocks
have been extensively faulted and folded
into complex geologic structures. Las
Vegas Valley is a structural depression
in the bedrock which has been filled with
alluvium forming a huge reservoir that,
for all practical purposes, is watertight.
The alluvial aprons are made up of num-
erous coalescing fans. They have much
less relief and the slopes are more gentle
and regular than those in the mountains.
These areas of deposition are eroded and
dissected. The alluvial deposits in the
Las Vegas Valley are composed princi-
pally of boulders, gravel, sand, silt and
clay derived from the adjacent mountain
ranges. These deposits contain virtually
16
-------
f " ,-,- i -_sv • y- , «.,,,;i°».i *,
,/i, j i-5LiW^5.A.x'\
? M'.CarranFiell-C
5^._ iiT.
EXPLANATION
CLARK COUNTY
Alluvium
Las Veu'as Formation
UMCONFORMITY
Volcanic rocks
TV, Illldiffl-l-filtiillt'll fulfil nil- rucks.
Tb, Fiiriificntimi HiiKiill Miiiihcr of
TKi
Intrusive rocks
• TKgr, hnlticriixtiill'itc rnck: mtiinhi t/mnUe, i/iiiirti
I T> mimziniiti'. (iniiiinl'.n-ili'./iiiil ilmrili-
I fi'TKi, niiilifiili'il iinrjilii/riti MicA's. Inelutlrx'urnnite
"vi'fihi// '/, i'h ijolitt, t filth i/ilulc I'ttf, innl nttii-r inlrn
.ves ranging from baanltic tit rhi/otitic
TKci. undifferentiated intnixiiH' rockx; mainly i/nurl;:
niiinzaniti: mill i/mritc cuntiiin/ni/ ruuj in-ndantx i,f
1'iilcti nic rock, I'ulr "nic li»ii'n/onr iiinl iliihnniti'. unit
/'• SCO intn'nl n rni'kx
•
i
17
-------
Contact
Lontj-iiaahfd where approximately located; short-dashed where sketched
or inferred
ss
Fault, showing dip or direction of dip
Long-dimhed wh»re approximately located; short-dashed where inferred;
dotted where concealed. • D, downthrown side of reverse fault. No
arrow on vertical or nearly vertical faults
Thrust fault
Saw-teeth indicate thrust plate. Dashed where approximately located;
dotted where concealed
Anticline
Showing trace of axial plane and direction of plunge of axis. Dashed
where approximately located
Overturned anticline
Showing trace of axial plane, direction of dip ofliinba, and plunge of axis
•f
Syncline
Showing trace of axial plane and direction of plunge of axis. Dashed
where approximately located
45
Strike and dip of beds
Strike and dip of overturned beos
Strike of vertical beds
e
Horizontal beds
Strike and dip of beds overturned through more than ISO-
Strike and dip of foliation
-*-
Strike of vertical foliation
-------
all the ground water of economic impor-
tance in the area. The maximum thick-
ness of this alluvial fill may be as much
as 5, 000 feet.
The basin lowlands, with low relief and
smooth surface, appear level in contrast
to the alluvial aprons and the mountains.
By comparison, little erosion takes place
in the lowlands which are sites of deposi-
tion for the large quantities of material
eroded from the mountains during and fol-
lowing heavy storms. The alluvial fill is
frequently interfingered with lenses of
silt and clay or stratified with alternate
layers of pervious sand and gravel and
less pervious silt and clay. There are
also frequent zones, of lime deposition
(caliche) which may be impermeable or
nearly so. It has been observed that
coarser materials are found in the west
and northwest portions of the Valley,
with finer materials occurring to the
south and southeast.
Playa deposits and sand dunes are pre-
sent in several locations in the basin low-
lands. Few dunes are active, being
mostly mounds built up around Mesquite
trees and covered with a thick growth of
Mesquite. Many scarps, resulting from
faults in the Valley fill, are found in the
southern part of the Valley near Las
Vegas. They vary in height from a few
feet to nearly 150 feet and are conspic-
uous features. Upward leakage and
springs occur along these scarps.
quakes in the past, and may reasonably
be expected to feel additional quakes in
the future. Earthquake activity apparently
increased following the filling of Lake
Mead, and is now decreasing again. The
regional and local seismic history and
fault structures of the Las Vegas area
have been taken into consideration within
the 1972 Design Appendix prepared by
NECON.
The Las Vegas Wash, an anomaly in the
desert, was made green as an unplanned
by-product of man's development of the
Valley. The Wash is considered to be that
area lying between desert riparian habi-
tats which border each side. The Wash
consists of two areas -- one is a wide,
dense marsh type area, and the second is
dense vegetation passing through high,
steep canyon walls.
Dry Lake Valley, is a north-south tren-
ding valley, five miles wide and eleven
miles long. It is bounded by steeply rising
mountain ranges, the Arrow Canyon
Range on the west and the Dry Lake Range
on the east. The southwestern end of the
valley is bounded by steeply rising hills
and lower gently-sloped passes, with the
northeastern end bounded by a rising mesa.
The valley is relatively flat, with a barren*
dry lake bottom at an elevation of 1, 968
feet, with gently rising moderately vege-
tated alluvial slopes rising to the foot of
the mountains. Dry Lake is dry except
after storms.
19
Las Vegas Valley has experienced earth-
At Dry Lake two deep holes were drilled
-------
in 1966 under the supervision of the
United States Geological Survey. One,
near the middle of the lake, penetrated
Holocene and Quarternary clays from the
ground surface to a depth of 310 feet,
then Pleistocene Muddy Creek formation
(mostly clays) from 310 feet to the total
depth of 1, 500 feet. A second deep hole,
on the alluvial fan to the west of the lake,
shows 35 feet of gravels at the top, Pleis-
tocene clay deposits from 35 to 185 feet,
Muddy Creek formation from 185 to 958
feet and Paleozoic limestones (bedrock)
from 958 to the total depth of 970 feet.
During June and July of 1972, Converse,
Davis and Associates, under contract with
the Las Vegas Valley Water District,
drilled some 21 holes in and around Dry
Lake. Except in the area well to the
south of the lake, clays were found at ele-
vations higher than those of the lake itself
(elevation 1,968). The south holes (No. 8
and 9) were not drilled deep enough to
reach the Muddy Creek formation. In
general, the clays show a cup-shaped con-
figuration, with gravels covering the per-
ipheral slopes.
Eldorado Valley is bounded on three sides
by steeply rising mountain ranges. The
McCullough Range bounds the western
side of the valley, the Highlands Range
to the south, Eldorado Mountains to the
east and a range of gently sloping hills
to the north, with Boulder City located at
their base. The Colorado River flows to
the south on the east side of the Eldorado
Mountains. The Valley encompasses 90
square miles with a barren flat, dry lake
located in the northeast section of the
valley floor. The dry lake bottom is at
1, 708 feet elevation and has an area of
about three and one-third square miles.
Rising from the valley floor are dense to
isolated vegetated alluvial slopes. The
geologic indications are that the dry lake
clays may not extend horizontally much
beyond the existing dry lake.
The Jean Lake portion of the Ivanpah
Valley, is bounded by gently rolling desert
on the north and northwest, the Sheep
Mountains on the west and southwest,
rising desert on the south and a range
of unnamed hills on the east. The valley
has a flat, barren dry lake bottom (Jean
Lake) which covers about two square
miles and lies at an elevation of 2, 780
feet with gently rising desert and allu-
vial slopes. The geologic indications
are that lake clays do not extend hori-
zontally much beyond the present dry
lake.
Hidden Valley contains an indistinct flat
dry lake bottom one-quarter square mile
in area at elevation 2,995 feet, and mod-
erately vegetated steep alluvial slopes.
The valley is relatively small, six miles
long and two miles wide. The geologic
indications are that the dry lake deposits
of Hidden Valley are very limited in
extent.
SOILS
The general soil map for a portion of
Clark County, Nevada has been prepared
at a scale of 1:500, 000 by generalization
of data from detailed and reconnaissance
soil surveys. It has been designed to dis-
20
-------
play soil landscapes,
Soil Formation
desert shrubs and annuals in the arid
valleys to sagebrush and pin yon-juniper
woodland at higher elevations on mountain
ranges.
The pertinent area is located in the south-
ern portion of the Basin and Range Physio-
graphic Province and includes a number of
generally north-south oriented mountain ran-
ges and intervening valleys. Important land-
forms include high mountains, foothills,
flood plains, terraces and mesas, playas,
sand dunes, and broad alluvial fans and
aprons which flank mountain ranges and
encroach on valley lowlands.
Soils in the general southwestern portion of
the area have formed in materials derived
dominantly from igneous granitic and vol-
canic rocks with admixtures of some mate-
rials from sedimentary and metamorphic
rock. In the remaining portion of the area
limestone, sandstone, quartzite, shale,
conglomerate and gypsiferous rocks are
the primary source of parent materials
for soils.
The soils in the area have formed under
a warm arid to semiarid climate. Ave-
rage annual precipitation in the valleys
varies between about 4 to 7 inches, and
in the mountains ranges upward to as
high as 20 inches. Average annual air
temperature in higher parts of mountains
is less than 47°F., and in the valley
ranges upward to more than 60°F.
Vegetation varies from a sparse stand of
The ages of landscape surfaces vary con-
siderably within the area. Relatively
recent surfaces include those of steep
mountain slopes where erosion is active,
and those of flood plains and alluvial
fans which are undergoing present-day ag-
gradation. Old surfaces occur on alluvial
fans and terraces which have been stable
over a very long period of time. Some of
these older surfaces are believed to date
back into the early Pleistocene. Surfaces
of intermediate age occur on land surfaces
which have experienced either erosion or
deposition of sediment at time periods be-
tween the older and recent surfaces. The
age of a surface reflects the time period
which soil parent material has been sub-
jected to weathering and soil development.
The older surfaces consequently have soils
with strongly developed profiles in which
original rock structure is not discernible.
Old soils within the area formed in parent
materials high in lime have large accumu-
lations of carbonates and some layers are
usually cemented. Those formed in mixed
materials usually have accumulations of
clay in their subsoils with underlying ce-
mented layers. In contrast to the older
soils, the soils of recent surfaces may
show very little modification except for
possibly organic matter gains and move-
ment of salts. Rock structure including
stratification of sediments is readily dis-
cernible in the young soils. Progressive
decrease in rock weathering, the accumu-
21
-------
lation and development of layers of calcium
carbonate, gypsum, clay and salts occur
as ages of surfaces transition from the old
to recent landscapes.
Because of the aridity of the climate,
soils formed on valley landscapes are gene
rally low in organic matter, and have ac-
cumulated soluble salts, lime and gypsum
in their subsoils. Lime-cemented hardpan
and high gypsum, accumulations charac-
terize old soils formed in valley-fill mate-
rials derived from sedimentary rock.
Clay accumulations overlying layers of
lime accumulation are typical for older
soils formed in materials derived from
igneous rock.
Transitions in kinds of soils of com-
parable age from the dry valleys to
those of semiarid mountainous land-
scapes is reflected in decreases in
accumulations of lime, gypsum, and
salts, and increases in organic
matter content.
Soil Map Units
Soil map units, delineated on the general
soil map, group a large number of dif-
ferent kinds of soil in accordance with
general characteristics. Major kinds of
soils and contrasting inclusions are de-
scribed.
General interpretations pertaining to suit-
ability for irrigated crops and pasture,
available water capacity (ability of soil
to store and yield water for plant use),
and susceptibility to water and wind ero-
sion are given for each of the major soils
comprising map units.
Use Of The General Soil Map
The general soil map has been designed to
display only broad soil patterns and asso-
ciated potential use limitations and ha-
zards. It can be used to compare different
parts of the area in order to ascertain po-
tential problems which may be associated
with specific uses. It is not suitable for
planning the use or management for a spe-
cific tract of land.
Soil Map Unit Descriptions
11.
--This unit consists of deep, saline,
silty clays and silty clay loams which
occupy nearly level basins (playas)
where slopes are less than 2 percent.
The soils are grayish brown in
color; moderately well to somewhat
poorly drained; and subject to oc-
casional flooding. They are slow
to very slowly permeable, and for
tne most part barren of vegetation.
The soils are not presently con-
sidered to be suitable for irrigated
crops or pasture. (Land capability
class VIII). The soils have a low
water erosion hazard, but will blow
if disturbed by construction, vehic-
ular traffic and similar disturbances.
22
-------
/,* '
. ,' .; • :,. -
"-*'.""!* v -\ *; I
' - -- ~
c --> T ~«* /1
-- 1—-s— '<:-
vsHictJen'"and Jean >p£
^flke. Valley.
-Eldorado Volley
• ; • i . A "•
*.£,.**•* 'V
'. • '-iv \\ W.'NJVI
GENERAL SOI L HAP
for
A Portion of Clark County, Nevtdt
August 1974
(Advanced Data for Interim Use)
Scale 1:500.000
This nip 1s Intended to display only broad soil patterns and
• •.sodated potential use limitations and hazards. It Is not
v'i',ibip for plannlm) the use and management for specific
tl-tci» of land.
6n»m ttmtti>N«i»nN wvn'r
k. 1 I* IWNIMtNt 0^ »iV*n *.MTl)NP
figure 8
-------
Included in the unit are less than 5
percent soils with sandy textures
and small gravelly areas along the
outer boundaries.
12. --This unit occurs on alluvial fans and
terraces in the southeastern part of
Las Vegas Valley.
Major soils comprising the unit in-
clude:
(a) About 40 percent light yellowish
brown, deep, well drained very
gravelly loamy sands to very
gravelly loams on lower alluvial
fans with 2 to 8 percent slopes.
Some of these soils have slight
to moderate calcium carbonate
cementation in the subsoils and
underlying layers.
Available water capacity for plants
is low; the profile permeability
is slow to moderate; and the po-
tential for water and wind erosion
is moderate. They are not con-
sidered suitable for irrigated
crops or pasture. (Land cap-
ability unit VII).
(b) About 35 percent pink, deep, well
drained, gravelly loamy sands
and sandy loams which contain
subsoil and substrata layers con-
taining considerable gypsum and
calcium carbonate. They occur
on old alluvial fans and terraces
with 2 to 4 percent slopes.
Available water capacity for
plants is low to moderate; the
profile permeability is mode-
rately slow; and the potential
erosion hazard from water
and wind is moderate to severe.
These soils are not suited for
irrigated crops or pasture.
(Land capability class VII).
Included with the major soils are
about 25 percent Badlands (eroded
scarps and breaks); deep, wet loams
and sandy soils along narrow flood
plains; and shallow loams and sandy
loams over indurated hardpan.
Small areas of the deep loams and
sandy soils are suited for irrigated
cropland.
The soils in the unit generally
have a low density cover for creo-
sotebush, white bursage, and some
grasses and annuals.
They are being used mostly for ur-
ban, commercial, industrial, and
related uses.
13. --This unit occurs on upper alluvial
fans and foothills mostly in the
southwestern part of Jean Lake
Valley.
Major soils comprising the unit
include:
(a) About 40 percent light yellowish
brown, deep, well drained,
very gravelly loams and very
gravelly sandy loams on upper
alluvial fans and foothills with
8 to 30 percent slopes.
24
-------
Available water capacity for
plants is low; the profile per-
meability moderate to mode-
rately rapid, and the potential
water and wind erosion hazard
is moderate. These soils are
not suited for irrigated crops
or pasture. (Land capability
class VII).
(b) About 30 percent yellowish red
to reddish brown, deep, well
drained, very gravelly loamy
sands on upper alluvial fans
with 4 to 8 percent slopes.
These soils have low available
water capacity for plants; the
profile permeability is mode-
rately rapid to rapid; and the
potential water and wind ero-
sion hazard is moderate. They
are suited for irrigated pas-
ture with very severe limi-
tations. (Land capability class
IV).
(c) About 20 percent reddish brown,
well drained, very gravelly clay
loams which are underlain by
lime-cemented hardpan at 20
to 40 inches. They occur on
upper alluvial fans with 4 to
8 percent slopes.
Available water capacity for
plants is low; the profile perme-
ability above the hardpan is mo-
derately slow; and the potential
water and wind erosion hazard
is moderate. The soils are
suited for irrigated hay and
pasture with very severe limi-
tations. (Land capability class
IV).
Included with the major soils are
about 10 percent shallow to very
shallow soils overlying hardpan,
and stony soils similar to the major
c omponent s.
The soils in the unit have low den-
sity cover of creosotebush, white
bursage, yucca, and some grasses
and annuals.
Present land use includes grazing,
wildlife and some recreation.
14. - -This unit occurs on lower mountain
slopes at elevations of about 4,500
to 7, 000 feet.
Major soils comprising the unit
include:
(a) About 40 percent light to dark
brown, deep, well drained,
very gravelly loams and very
gravelly sandy loam on 8 to
30 percent slopes.
Available water capacity for
plants is low; the profile per-
meability is moderate to mo-
derately rapid; and the poten-
tial erosion hazard for water
and wind is moderate to slight.
These soils are not suited for
irrigated crops or pasture.
(Land capability class VII).
(b) About 25 percent light brown,
well drained, very gravelly
25
-------
sandy loams and very gravelly
loamy sands overlying lime-
cemented hardpan at less than
20 inches. They occur on 8 to
30 percent slopes.
Available water capacity for
plants is low; the profile per-
meability above the hardpan
is moderately rapid; and po-
tential erosion hazard for water
and wind is severe to moderate.
These soils are not suited for
irrigated crop or pasture.
(Land capability class VII).
(c) About 25 percent rock outcrop
(limestone, quartzite, dolomite,
sandstone) on 15 to 50 percent
slopes. (Land capability class
VIII).
Included with the major soils are
about 10 percent shallow to very
shallow soils on bedrock, and very
stony soils similar to the major
components.
The soils in the unit have a cover
of shrubs mostly yucca, white
bursage and creosotebush at lower
elevations which grade through black-
brush to sagebrush, jumper, pinyon,
and other shrubs at higher elevations.
Present land use includes grazing,
wildlife and some woodland, and
recreation.
15. --This unit occurs on mountain
slopes at elevations of about
5,000 to 7, 000 feet.
Major soils comprising the unit
include:
(a) About 40 percent rock outcrop
(intrusive and extrusive vol-
canics) on 15 to 50 percent
slopes. (Land capability
class VIII).
(b) About 35 percent reddish brown,
well drained, gravelly loams
to very gravelly sandy loams
which are underlain by hard
bedrock at 10 to 20 inches.
They occur on 15 to 50 percent
slopes.
Available water capacity for
plants is low; the profile per-
meability above bedrock is
moderate; and the potential
erosion hazard by water
is severe. Not suited for
irrigated crops or pasture.
(Land capability class VII).
(c) About 15 percent light reddish
brown, gravelly sandy clay
loams overlying hard bedrock
at 10 to 20 inches. They occur
on 8 to 15 percent slopes.
Available water capacity for
plants is low; the profile per-
meability above bedrock is
moderately slow; and the ero-
sion hazard by water is severe.
Not suited for irrigated crops
or pasture. (Land capability
class VII).
Included with the major soils are about
26
-------
BASIN
W>
It
3
<0
»
1 _i--H3Lr J'i J ^NX-fe-^r-V K
>oct^a"1^ /k lv- r I
I 'AS -r to " V, N ^- y—' , J >
wK V" S -lifi ^~
* NOTE Areas of this class were loo
small to be mapped
''UPPER
REGION
LEGEND
SEDIMENT YIELD CLASSES
> -30 Acre Feet Per Square Mile Per Year
1.0-30 Acre Feet Per Sauare Mile Per Year
0.5 - 1.0 Acre Feet Per Square Mile Per Year
02-05 Acre Feet Per Square Mile Per Year
< -0.2 Acre Feet Per Square Mile Per Year
Water
^-xfVx-< —
_J> rS-v, f I I**.
Region Boundary
Subr'egion Boundary
State Boundary
(
p\ \ v4
* \.' ^ \ ^~~~~~,
C^i^Ar'
\ _J >»* I rO = C-i«TAP
J ' i •»'."' ,—, s\ ' \
y^y 7^4\
/r^;- ^i \
I -\ij^<^^i-
County Boundary
^V'1 r ^D:;!/". ->/y i
r vv.-- ,
<
• \/ N A V A J 0 ^
• I — -~ ^ I A P A C H E-"
^.-\'IJ^ -^
'. .1 .J (
CAuiFORNiA
REGION
if.W/^'./^'
,^-i \
,_ • Ji *J -SI JOMW^.'. ' - j
•Xir-f^-
"
-------
10 percent deep gravelly loams and sandy
loams, and very stony and extremely
stony soils similar to the major compo-
nents.
The soils in this unit have a highly varied
plant cover which includes numerous
shrubs and grass species, and pinyon and
jumper at higher elevations.
Present land use includes grazing, wild-
life, and some watershed and recreation.
21. --This unit occurs on flood plains,
and low adjacent alluvial fans and
terraces. The component major
soils are subject to occasional
flooding.
Major soils comprising the unit
include:
(a) About 40 percent grayish brown,
deep, moderately well to some-
what poorly drained silty clays
and silty clay loams on flood -
plains with 0 to 2 percent slopes.
Available water capacity for
plants is high; the profile per-
meability is slow; and the po-
tential wind and water erosion
hazard is moderate. These
soils are suited for irrigated
crops and pasture with severe
limitations. (Land capability
class IE).
(b) About 30 percent pale brown,
deep, well drained gravelly
loamy sands and gravelly loams
on flood plains and low adjacent
alluvial fans and terraces with
0 to 2 percent slopes.
Available water capacity for
plants is moderate; the profile
permeability is moderately slow
to moderate; and the potential
wind erosion hazard severe.
These soils are suited for irri-
gated crops and pasture with
severe limitations. (Land
capability class III).
(c) About 20 percent light brown,
deep, well drained loamy sands
on flood plains and adjacent low
terraces, alluvial fans, and
dune areas with 0 to 8 percent
slopes.
Available water capacity for
plants is low; the profile per-
meability is moderately rapid;
the potential wind erosion haz-
ard is high. These soils are
suited for irrigated crops and
pasture with severe limitations.
(Land capability class III).
Included among the major soils in the unit
are about 10 percent stony soils and deep
very gravelly sandy soils.
The soils in the unit have a low density
plant cover consisting of saltbush, creo-
sotebush and white bursage.
Present land use includes grazing, wild-
life, and some recreation.
28
-------
41. --This unit occurs oft alluvial fan
toeslopes and on inset alluvial fans
where slopes are less than 8 per-
cent.
Major soils comprising the unit
include:
(a) About 35 percent reddish brown,
deep, well drained sandy loams
on alluvial fan toeslopes with 2
to 8 percent slopes. Some of
these soils contain slight to
moderate lime cementation in
their subsoils.
Available water capacity for
plants is moderate; the profile
permeability is moderate to
moderately rapid; the potential
water and wind erosion hazard
is severe and moderate. These
soils are suited for irrigated
crops and pasture with severe
limitations. (Land capability
class III).
(b) About 30 percent pinkish brown
to brown, deep, well drained
gravelly sandy loams and gra-
velly loams on inset alluvial
fans with 0 to 4 percent slopes.
Some of these soils contain
gypsum accumulations in their
subsoils.
Available water capacity for
plants is low to moderate; the
profile permeability is mod-
erately slow to moderate;
and the potential wind and water
erosion hazard is moderate.
These soils are suited for irri-
gated hay and pasture with
very severe limitations.
(Land capability class IV).
(c) About 15 percent pink, well
drained, gravelly fine sandy
loams underlain by lime-
cemented hardpan at 10 to 20
inches. They occur on allu-
vial fan toeslopes with 2 to 8
percent slopes.
Available water capacity for
plants is low; the profile per-
meability to the hardpan is
moderate to moderately rapid;
and potential water and wind
erosion hazard is moderate
to severe. These soils are
suited for irrigated crops or
pasture. (Land capability
class VII).
Included.with the major soils in the unit
are about 20 percent deep, wet, saline
silt loams, and deep, well drained sand;
badlands; stony soils; and deep clays
adjacent to playas. Small areas of in-
cluded deep soils are suited for irrigated
cropland and pasture.
The soils in the unit have a shrub-plant
cover consisting mainly of creosotebush,
white bursage, and some grasses, an-
nuals, saltbush and yucca.
Present land use includes grazing, wild-
life, urban, industrial, and some recrea-
tion.
29
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42. --This unit occurs oh alluvial fans
and foothills where slopes are 4 to
30 percent.
Major soils comprising the unit
include:
(a) About 35 percent reddish yellow
to reddish brown, deep, well
drained gravelly and very gra-
velly sandy loams on smooth
and dissected alluvial fans with
4 to 15 percent slopes. Most
of these soils have slight to
moderate lime cementation in
their subsoils.
Available water capacity for
plants is low to moderate; the
profile permeability is moderate
to moderately rapid; the poten-
tial water and wind erosion haz-
ard is moderate. The soils are
not suited for irrigated crops
or pasture. (Land capability
class VII).
(b) About 35 percent light brown,
well drained, very gravelly
loamy sands and very gravelly
sandy loams which are under-
lain by lime-cemented hardpan
at less than 20 inches. They
occur on smooth and dissected
alluvial fans with 4 to 15 per-
cent slopes.
Available water capacity for
plants is low; the profile per-
meability to the hardpan is
moderately rapid; and the
potential for water and wind
erosion is moderate. These
soils are not suited for irri-
gated crops or pasture. (Land
capability class VII).
(c) About 20 percent pale brown,
deep to moderately deep, we'll
drained, stony and cobbly very
gravelly sandy loams and very
gravelly sands on foothills and
inset alluvial fans with 4 to 30
percent slopes.
Available water capacity for
plants is low; the profile per-
meability is moderate to rapid.
These soils are not suited for
irrigated crops or pasture.
(Land capability class VII).
Included with the major soils are about
10 percent deep, gravelly sandy loam,
soils which are underlain by bedrock,
and some gypsiferous very gravelly
soils.
The soils in the unit have a sparse plant
cover of creosote bush, white bursage
and some yucca, annuals, and saltbush.
Present land use includes grazing and
wildlife and some urban, industrial, and
recreation.
43. --This unit occurs on high moun-
tain slopes at elevations of about
5,000 to 10,000 feet.
Major soils comprising the unit
include:
30
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(a) About 35 percent yellowish
brown, moderately deep to deep,
well drained, stony very gra-
velly loams overlying bedrock
with 8 to 30 percent slopes,.
Available water capacity for
plants is low to moderate; the
profile permeability is mod-
erately slow to moderate, and
the potential erosion hazard
by water is severe. These
soils are not suited for irri-
gated-crops or pasture.
(Land capability class VII).
(b) About 30 percent pale brown to
dark brown, deep to moderately
deep, stony and very stony very
gravelly sandy loams and very
gravelly loamy sands overlying
bedrock with 4 to 50 percent
slopes.
Available water capacity for
plants is low; the profile per-
meability is moderately rapid;
potential erosion hazard by
water is severe. These soils
are not suited for irrigated
crops or pasture. (Land capa-
bility class VII).
(c) About 25 percent brown, well
drained, stony and very stony
gravelly loams which are under-
lain by bedrock at 10 to 20
inches. They occur on 8 to
50 percent slopes.
Available water capacity for
plants is low; the profile per-
meability above bedrock is
moderate; potential erosion
hazard by water is severe.
These soils are not suited for
irrigated crops or pasture.
(Land capability class VII).
About 10 percent of the unit includes with
the major soils: rock outcrops, rock rub-
ble, and more steeply sloping soils simi-
lar to the major components.
The soils in the unit have a plant cover
which includes sagebrush, grasses, forbs,
pinyon pine, juniper, and various species
of mountain shrubs.
Present land use includes grazing, wild-
life, watershed, and recreation.
51. --This unit occurs on valley ter-
races and alluvial fans.
Major soils comprising the unit
include:
(a) About 60 percent pale brown,
well drained, gravelly sandy
loams and loamy sands which
are underlain by lime-cemented
hardpan at 10 and 20 inches.
They occur on 0 to 8 percent
slopes.
Available water capacity for
plants is low; the profile per-
meability above the hardpan is
moderate to moderately rapid;
and potential water and wind
erosion hazard is moderate.
31
-------
These soils are not suited for
irrigated crops or pasture.
(Land capability class VII).
(b) About 30 percent reddish yellow
to pale brown, deep, well
drained, gravelly and very gra-
velly sandy loams with 2 to 8
percent slopes.
Available water capacity for
plants is low; the profile per-
meability is moderate to
moderately rapid; potential
water and wind erosion hazard
is moderate. These soils are
suited for irrigated hay and
pasture with very severe limi-
tations. (Land capability
class IV).
About 10 percent of the unit includes soils
overlying bedrock at very shallow depth,
stony soils, and soils overlying hardpan
at less than 10 inches.
The soils in the unit have a sparse plant
cover consisting of creosotebush, white
bursage, yucca, and some annuals.
Present land use includes grazing, wild-
life, urban, industrial, and some recrea-
tion.
Glossary
Soil map unit - A specific area of major
kind(s) of soil and minor included soils
which are delineated on soil maps.
Soil depth - (To hardpan or bedrock)
Very shallow: le,ss than 10 inches.
Shallow: 10-20 inches.
Moderately deep: 20 - 40 inches.
Deep: more than 40 inches.
Profile permeability - (Excluding permea-
bility of hardpan or bedrock)
Very slow: less than 0.06 in./hr.
Slow: 0.06 - 0.2 in. /hr.
Moderately slow: 0. 2 - 0. 6 in. /hr.
Moderate: 0.6 - 2.0 in. /hr.
Moderately rapid: 2.0 - 6.0 in. /hr.
Rapid: 6.0 - 20 in. /hr.
Very rapid: more than 20 in. /hr.
Available water capacity - The inherent
capacity of soil to store and yield water
for use by plants. As used herein it
indicates the estimated total within the
soil to a depth of 5 feet or to hardpan
or bedrock if at a depth shallower than
5 feet.
Low: less than 4.0 inches.
Moderate: 4.0 - 7.0 inches.
High: more than 7.0 inches.
Land capability classification - Groupings
of soils which show in a general way, the
suitability of soils for common field crops,
The soils are grouped according to their
limitations when used for crops, the risk
of damage when they are used, and the
way they respond to treatment.
Class I - soils have few limitations that
restrict their use.
Class II - soils have moderate limita-
tions that reduce the choice
of plants or that require
32
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moderate conservation
practices.
WATER RESOURCES
ClassIII- soils have severe limitations
that reduce the choice of
plants, require special
conservation practices, or
both.
Class IV - soils have very severe limi-
tations that reduce the choice
of plants, require very care-
ful management, or both.
Class V - soils are subject to little or
no erosion but have other
limitations, impractical to
remove, that limit their use
largely to pasture, range,
woodland, or wildlife habitat.
Class VI - soils have severe limitations
that make them generally un-
suited to cultivation and limit
their use largely to pasture
or range, woodland, or wild-
life habitat.
Class VII - soils have very severe limi-
tations that make them un-
suited to cultivation and that
restrict their use largely to
pasture or range, woodland
or wildlife habitat.
Class VIII- soils and landforms that have
limitations that preclude their
use for commercial plants and
restrict their use to recrea-
tion, wildlife habitat, or water
supply or to esthetic purposes.
Regional Hydrology
The Las Vegas Ground Water Basin is
comprised of the alluvial fill of Three
Lakes Valley, the southern part of Indian
Spring Valley, the northern part of Ivanpah
Valley, and Las Vegas Valley. The en-
tire Basin is surrounded by a series of
high mountain ranges which act as bar-
riers to ground water movement and form
the general limits of the ground water
basin. From a hydrologic standpoint,
the Spring Mountains that make up the
western topographic divide, are the domi-
nant features of the watershed. These .
mountains are the highest in the region,
and large alluvial fans from these moun-
tains extend far out into the Valley below.
In contrast, the alluvial fans from the
eastern side of the Valley are small in
areal extent.
Based upon their hydrologic properties,
the geologic formations of the area can
be divided into two general groups; (1)
consolidated rocks of low permeability
that underlie the alluvium in the Valley
and form the mountains that encircle the
ground water basin, and (2) the relatively
permeable sedimentary deposits of the
valley fill that form, the Las Vegas ground
water basin. These alluvial deposits con-
tain virtually all of the ground water of
economic importance in the basin, occur-
ring in a large, leaky artesian system
under both confined and unconfined
conditions.
Major drainage within the watershed is
33
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towards the southeast through Las Vegas
Wash to the Colorado River. Storm run-
off is usually limited to the higher eleva-
tions above 6, 000 feet where it ultimately
infiltrates into the porous alluvial fans.
After intense summer storms, however,
runoff may be sufficient to flow onto the
floor of the Valley, and discharge into
Las Vegas Wash.
Las Vegas Bay is a part of the Boulder
Basin area of Lake Mead which covers
a surface area of 157, 736 acres and
drains an area of 167, 800 square miles.
The largest reservoir in the United
States, its usable capacity is 27,207,000
acre feet. As a multipurpose reservoir
it is used for flood control, irrigation,
municipal uses, navigation, and power.
The Colorado River is the main source
of surface inflow into Lake Mead. The
nearest stream-gaging station, which is
near Grand Canyon, Arizona is 190 river
miles above the convergence (at usual
reservoir levels), which is defined as
the boundary between the muddy Colo-
rado River water and the clear Lake
Mead water. The only Colorado River
tributary below the Grand Canyon gaging
station whose flow is measured is Bright
Angel Creek, which enters the main stream
a quarter of a mile below the Grand Canyon
gaging station. All other tributaries
between Bright Angel Creek and the con-
vergence are unmeasured. Time of
travel for measured flows between Grand
Canyon and the head of the reservoir, is
from two to three days depending on the
flow. Virgin River is the only other
major tributary to Lake Mead whose
flow is measured.
Unmeasured inflow includes the runoff
entering Colorado River between the
mouth of Bright Angel Creek and the
head of the reservoir, and flow of all
streams except those of the Virgin River
that discharge directly into Lake Mead.
The area from which this runoff is de-
rived has topographic and climatic
characteristics not greatly different
from those of the Virgin River basin.
Unmeasured runoff is therefore, con-
sidered to be proportional to Virgin
River flow.
Reservoir releases are the major sur-
face outflow from Lake Mead. Outflow
is measured at a stream-gaging station
located one mile below Hoover Dam and
the records thus obtained are checked
against figures obtained from power
plant records. Pumping from Lake Mead
for domestic and industrial uses, is less
than one-tenth of one percent of the out-
flow and is disregarded.
The capacity of the reservoir is slightly
reduced because of the addition of sedi-
ment to the Lake. The slight change in
capacity is of little consequence because
the sediment is deposited at the bottom
of the Lake, where the temperature of
the water remains almost constant
throughout the year. Thus, the small
capacity change has no effect on com-
puted figures of change in energy
storage. Changes in Lake stage are
recorded on a Stevens remote-register-
ing gage with the actuating element
mounted over a stilling well built into
Hoover Dam. The gage-indicator dial
and a Stevens water-stage recorder are
located in the powerhouse.
34
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The Lower Main Stem Subregion of the
Lower Colorado Region includes the
Colorado River drainage basin from Lee
Ferry (one mile downstream from the
Paria River) to the southerly interna-
tional boundary with Mexico, -with the
exception of the Little Colorado River Ba-
sin, the Gila River Basin above Painted
Rock Dam, and the California portion of
the Colorado River Basin. In addition,
the Subregion includes Mexican drainage
west of Lukeville, Arizona and closed
basins in Southeastern Nevada covering
3, 200 square miles. The total area is
56,554 square miles, of which 17,310
square miles are in Nevada. About
52, 100 square miles of the area contri-
bute to the Colorado River. The River
follows a generally westerly course from
Lee Ferry through the Grand Canyon and
into Lake Mead. Below Lake Mead, it
flows southward forming the border be-
tween the States of Arizona and Nevada
and further south, Arizona and California.
Elevations range from near 12,000 feet
at Charleston Peak near Las Vegas to
about 75 feet at the southerly interna-
tional boundary. Between Lee Ferry and
Hoover Dam (353 river miles) the prin-
cipal tributaries are the Little Colorado
River, the Virgin River, Bright Angel,
Tapeats, Kanab; and Havasu Creeks,
and Las Vegas Wash. Springs contri-
bute about 300,000 acre-feet annually
in this reach. (Refer to Figure 1)
The total long-term average annual unde-
pleted tributary runoff to the Colorado
River is estimated at nearly 2.4 maf,
including over 1 maf from the Gila River
and 0.4 maf from the Little Colorado
River. The undepleted net gain of the
Colorado River from Lee Ferry (15.09
maf) to the international boundary (15. 94
maf) is about 0.85 maf annually. Since
the undepleted inflow to the main stem is
estimated as about 2.4 maf, an apparent
river loss of 1. 5 maf under the natural
environment is indicated. Present water
requirements in the Subregion, are esti-
mated as 1.3 maf annually. Additional
demands on the supply of the river below
Lee Ferry are for main stem reservoir
evaporation and spills, channel losses,
exports to the California Region, and
Mexican Treaty obligations. These
demands presently total about 9 maf
annually.
The water supply available for use in the
Lower Main Stem Subregion consists of
(a) natural runoff originating in the Sub-
region, (b) a portion of the Main Stem
Colorado River water released from the
Upper Colorado Region at Glen Canyon
Dam under the provisions of the Colo-
rado River Compact, and (c) ground
water. Most of the presently available
runoff originating in the Subregion occurs
between Lee Ferry and Hoover Dam.
Releases from Glen Canyon Dam consti-
tute the Subregion1 s major water source.
Completed in 1963, Glen Canyon Dam
provides the storage required to meet
downstream water requirements under
the Colorado River Compact of 1922,
storage requirements for Upper Colo-
rado Region water development, and
for power production.
In 1965, gross ground-water pumpage
35
-------
18— -
tt
U
11
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115 O
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a
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u
13— —-
1100-
AVAILABLE BTORAOE
• YEAR'S MAXIMUM
• YEAR'S MINIMUM
_e L^_V A T I a N
• YEAR'S MAXIMUM
• YEAR'S MINIMUM
1B8B
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YEAR
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LAKE IVIEAD STt)R/\C3E AND SURFACE EL E VATIOISIS
-------
provided over one-half million acre-feet
to satisfy uses in the Subregion. Ground-
water overdraft occurs in some areas,
notably in Nevada. The Southern Nevada
Water Project, currently under construc-
tion, will provide the facilities to develop
the major portion of Nevada's Colorado
River entitlement and will reduce the
rate of overdraft in Las Vegas Valley.
The surface-water supply of the Lower
Main Stem Subregion depends almost
entirely on releases from Glen Canyon
Dam, and on the operational criteria
governing releases of water from Lake
Mead. Between Lee Ferry and the head
of Lake Mead, many of the tributaries
flow only during periods of heavy rainfall;
however, several are fed by springs and
are perennial. Tributary runoff varies
widely from 0. 3 inches for the Little
Colorado River to about 5 inches for
Bright Angel Creek on the north side of
the Colorado River.
Nevada's portion of the Colorado River
basin is almost entirely tributary di-
rectly to Lake Mead. The Muddy River
flows into the Overton arm of the Lake
and has a drainage basin of 8, 200 square
miles; however, the actual inflow to
Lake Mead from this large area is
restricted in most years to the water
discharged from the Moapa Springs after
it has been used extensively for irrigation
in Moapa Valley. Las Vegas Valley also
is tributary to Lake Mead, but its contri-
bution is chiefly in flood runoff from the
lower part of the Valley plus a small
amount of effluent seepage from the
ground-water reservoir. Like the inter-
montane valleys in the White River basin,
Las Vegas Valley is analogous to valleys
in the Great Basin in that the precipitation
upon its drainage area is practically all
returned to the atmosphere within that
area; but, Las Vegas Valley is closely
related to the Colorado River because
it imports water from Lake Mead.
The Subregion has a total water supply
in excess of its own present requirements.
Supplies exceed depletion requirements by
1. 3 to 2.5 million acre-feet annually, de-
pendent upon the runoff period inspected.
Seasonal water shortages do occur, how-
ever, principally on the developed tribu-
taries of the Colorado River. These
shortages are due to the erratic nature
of the water supply and to lack of adequate
storage and conveyance facilities. The
authorized Southern Nevada Water Project
will shortly provide the facilities to con-
vey a part of Nevada's allocation of Colo-
rado River water into the area of greatest
demand, the Las Vegas-Eldorado Valley.
This development should be adequate to
meet Nevada's rapidly growing water
requirements into the immediate future.
Continuation of the present rapid growth,
however, could exceed the capability of
the present systems to meet demands
much beyond 1980. Additional facilities
are necessary to allow full development
of existing Federal projects and to pro-
vide the necessary land and water deve-
lopments to meet the increasing recrea-
tion pressures along the Lower Colorado
River.
Future main stem reservoir evaporation
can be expected to decline without aug-
mentation, but not by great amounts
37
-------
through the 2020 level of development.
Main stem channel losses are also pro-
jected to decline as a result of the autho-
rized Bureau of Reclamation Colorado
River program for increasing water
yield. The present losses of 660, 000
acre-feet were accordingly reduced by
170,000 acre-feet from selective phrea-
tophyte control and by 170 acre-feet
from river channelization.
Future water supplies available to the
Subregion will decline from 11.42 maf in
1980 to 9. 65 maf in 2020. Water require-
ments exceed the available water supply
in year 2020, even under a favorable run-
off period. Nevada is grossly short of
water to meet demands, and the problem
needs to be solved through development
of sources other than the Colorado River,
be it augmentation or by further use of
Nevada ground-water resources.
Shallow ground water is found in Las
Vegas Valley at depths from 1 to 50 feet
below ground surface. This shallow water
body is referred to as the near-surface
aquifer. Water within this aquifer is
generally unconfined in the Las Vegas
Valley. The maximum thickness of the
near-surface aquifer system is about 200
feet thick. Beds and lenses of caliche,
sand, silt and clay make up the near-
surface aquifer system. In the Valley
these beds are commonly saturated with
ground water within a few feet of the sur-
face. Recharge of the near-surface aqui-
fer occurs from upward leakage from the
deeper aquifers and from surface recharge
from cooling water, sewage effluent, lawn
and parkway irrigation and possibly from
surface ponding of storm runoff. While
the chemical character of the near-sur-
face ground water varies considerably
across the Valley, most samples have
been high in total dissolved solids (TDS)*.
Area Hydrology
Geologists have divided the aquifers un-
derlying Las Vegas Valley into four prin-
cipal hydrologic units on the basis of their
stratigraphic positions. These are the
near-surface aquifer from ground surface
down to about 200 feet, the shallow zone of
aquifers from 200 to 500 feet, the middle
zone of aquifers from approximately 500
to 700 feet, and the deep zone aquifers
below 700 feet. Water in the near-surface
aquifer occurs under both water table (un-
confined) and artesian conditions, while
water in the last three hydrologic units
occurs under artesian (confined) condi-
tions.
From the city limits of Las Vegas south-
east to the Las Vegas Wash, shallow
ground water is unsuitable for either
domestic or irrigation uses because of
high mineralization.
In the Las Vegas Valley there are three
major aquifer zones which are under pres-
sure. Each of these aquifers has its
^Typically TDS levels range from 2000
to 8, 000 mg/ 1. Measurements assembled
by the Desert Research Institute, Univer-
sity of Nevada, indicate that the average
concentration may approach 5, 000 mg/1.
38
-------
own pressure (piezometric) surface or
level; the deeper zones are generally un-
der greater confining pressure. Within
the Valley, pressures within the various
aquifers have tended to become equalized
by vertical movement of water within in-
dividual water wells and between forma-
tions. Vertical interchange between aqui-
fers has resulted because of irregular de-
position and erosion of sediments, faulting
in the valley fill and leakage due to im-
proper well construction. Geologic inves-
tigations of the southeast part of Las
Vegas Valley have indicated that only in-
significant amounts of this confined water
escapes from the Valley via subsurface
flow. Studies of the Valley margins in-
dicate that escape of the underground water
is unlikely in any part of the Valley.
Total discharge of waters from the upper,
middle and lower aquifer zones is repre-
sented by well extractions, upward leakage
into the near-surface aquifer and dis-
charge into springs. The shallow zone of
aquifers lies between 200 and 500 feet
below ground surface. Four principal
sand and gravel lenses within this hori-
zon provided most of the potable water
from the Valley prior to 1940. A marker
bed of blue clay separates the shallow
zone from the middle zone. The middle
zone of aquifers lies from 500 to 700
feet deep. This is the most productive
aquifer in Las Vegas Valley and pre-
sently supplies most of the water pumped
in from the Basin. All of the aquifers
lying below 700 feet have been included
in the deep zone of aquifers. Only small
quantities of water are presently being
withdrawn from this depth. The sediments
consist of siltstones interbedded with thin,
sandy strata of fine sand and silt. All or
most of the deep zone aquifers occur in
the Muddy Creek formation.
Almost all of the natural recharge that
occurs to the confined aquifer system is
by infiltration of rainfall and runoff oc-
curring principally in the Spring Moun-
tains and in the Sheep Range. At alti-
tudes above 6,000 feet, rainfall commonly
accumulates in quantities sufficient to per-
mit some water to percolate through the
alluvial material into the saturated ground-
water zone. Runoff from heavy mountain
rainfall infiltrates into the fractured
mountain rock and into the porous allu-
vial aprons where it can percolate down-
slope into the Valley fill. The main
recharge (intake) area for the Las Vegas
ground water basin is probably along the
base of the mountains, particularly to the
west in the areas of the large alluvial
fans radiating out from the Spring Moun-
tains. From these principal recharge
areas, the ground water moves down-
slope and laterally in the direction of the
hydraulic gradient toward the discharge
areas to the southwest portions of the
Valley. In the lower parts of the Basin
below elevation 6, 000 feet, the annual
rainfall averages less than five inches
per year. There is probably no direct
natural recharge to the near-surface
or the confined aquifers, because of the
high soil moisture demand. All of this
rainfall is undoubtedly lost to the pro-
cesses of evaporation and transpiration.
Ground-water recharge via septic tank
effluents in the Valley contributed another
1, 254 acre-feet during 1973. Seepage
from the BMI waste-water discharge
-------
ponds may have been responsible for
adding another 5,000 acre-feet of highly
mineralized water during 1973. Thus,
the total recharge to the near-surface
ground-water system from man's activity
in the Valley was in excess of 40, 000
acre-feet during 1973. The quantity of
new salt which was carried into the
ground-water system by man's actions is
not quantifiable at this stage of investiga-
tion, but the amount must be significant
as evidenced by the very high TDS levels
of the upper horizon of the near-surface
ground-water system.
Of the total of 47, 996 acre-feet of water
which was applied to lawns and crops
throughout the Valley, about 9,427 acre-
feet was supplied from secondary treated
effluent. Odor and soil plugging problems
have been experienced in using secondary
treated effluent for golf course irrigation
in Las Vegas Valley. In 1973, the odor
prpblem became so acute at the Winter-
wood Golf Course that they are converting
to use of ground water to alleviate the
problem. It appears that the use of se-
condary effluent where land is not culti-
vated will be seriously restricted in light
of the problems encountered.
The complexity of the Las Vegas ground-
water basin due to the nature of sedi-
ment deposition and subsequent faulting
within the alluvium, has created many
obstacles to understanding hydrodynamics
of subsurface flow. While there have
been many ground-water wells drilled
within the Valley, there were virtually
none that were constructed for monitor-
ing both water levels and water quality
of specific aquifers.
Low in the Valley and closer to the Las
Vegas Wash, where the sands and gravels
become thin, the artesian water slowly
leaks upward through silts and clays and
contributes to high water tables. Before
the advent of man, all the water recharged
to the Las Vegas ground-water basin was
discharged by evapotranspiration - a
combination of evaporation and transpira-
tion by specialized plants (phreatophytes)
which thrive in places where the water
table is close to the ground surface. In
those early days, all the water was con-
sumed in the upper reaches of Las Vegas
Wash and there was no perennial flow in
the lower reaches. Presently, all water
delivered to the developed portions of Las
Vegas Valley which is not consumed,
returns to the near-surface aquifers.
Thus, all cesspool and septic tank con-
tributions must be considered as recharge
to the near-surface aquifers. Irrigation
of any type, such as for agriculture or
golf courses, has limited efficiency.
This means that more water must be
delivered than the plants use. The conse-
quence of this is that there is always
some water which moves down through
the irrigated soils and joins the near-sur-
face aquifers. Such water is always
higher in dissolved minerals than the
water which is delivered. Under present
conditions, this irrigation return water,
now in the near-surface aquifers, will
move downslope, rise to the ground sur-
face, and augment the present surface
flow of Las Vegas Wash. In addition to
these ground-water flows, the Wash has
4O
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become the principal channel for removal
of much of the treated municipal and in-
dustrial waste water produced in the
Las Vegas Valley. The present waste
water flow of more than 40 million gal-
lons per day (mgd) supports a perennial,
densely vegetated marsh of about 2, 000
acres, with a diverse and abundant wild-
life population.
Dry Lake, Eldorado, Jean Lake, and
Hidden Valleys are characterized by
deep water tables, indicating that natural
recharge, however small, must be es-
caping via underground exits. Concern
has been expressed that sewage effluent,
if spread on these dry lake and flanking
alluvial fan areas, would percolate to
great depths, to join and pollute the deep
regional ground waters.
At Dry Lake, results of laboratory tests
indicate that percolation to the deep water
table would be extremely slight, and for
all practical purposes, insignificant.
From Eldorado Valley there is believed to
be underground leakage easterly through
the volcanic rocks of the Eldorado Moun-
tains to the Colorado River below Hoover
Dam. A deep well near the south end of
the dry lake encountered bedrock at a
depth of 1, 040 feet. This well was drilled
through low permeability materials to a
depth of 475 feet, where an artesian aqui-
fier was reached. The water rose 200
feet'to a depth of 275 feet. This well
was pumped for 14 hours at 920 gallons
per minute with a. drawdbwn of 95 feet.
The water had a total dissolved solids
content of 1, 275 ppm. In Eldorado Valley
Converse, Davis 8* Associates drilled
three bucket auger test borings to depths
between 37 and 48 feet, and one rotary
wash boring to a. depth of 80 feet. The
Muddy Creek formation, as a thick, low
permeability zone, does not appear to
be present at depth. Thus, water spread
on the peripheral alluvial fan surfaces
may have an opportunity of reaching the
regional ground water. There is believed
to be deep drainage from beneath Jean
Lake easterly into Eldorado Valley and
northerly into Hidden Valley.
The deepest well near Jean Lake was
drilled to a depth of 470 feet; depth-to-
water is about 343 feet. The water has
an electric conductivity of 1, 300. The
indications are that the yield of the well
was very low. Converse, Davis & Asso-
ciates drilled two bucket auger borings
to depths of 22 and 41 feet, and two
rotary wash borings to depths of 60 and
105 feet. Spreading of water on the
peripheral alluvial fan might result in
substantial downward leakage to the
regional ground water.
In Hidden Valley, one well was drilled
to a depth of 1,490 feet; depth-to-water
is about 950 feet. No more than one-
fourth mile to the northwest, across the
McClanahan Fault, depth-to-water is
only about 600 feet. Converse, Davis &
Associates drilled one 33-foot bucket
auger boring near the middle of the dry
lake in Hidden Valley. The dry lake
deposits are very limited in extent and if
41
-------
water is spread on the peripheral alluvial
fans, there are no thick lake clays to
prevent percolation to the regional
ground water.
WATER QUALITY
Historically, the initial negotiations of
water allocation among the states of the
Colorado River Basin was primarily a
matter of who was going to get how much
rather than whether it was of a quality
they could use once they got it. The
Colorado River Compact, in 1922, was
set up to provide for the diversion of
waters in the Colorado River System.
It also established a preference for
agriculture and domestic uses over all
other uses. However, no explicit pro-
visions regarding water quality was
contained.
The United States and Mexico in 1944 ad-
opted a Treaty for the Utilization of the
Colorado and Tijuana and of the Rio Grande.
The Treaty, allotted to Mexico 1, 500, 000
acre-feet annually ... of the waters of
the Colorado River, from any and all
sources. . ." The delivery of treaty
waters to Mexico began in 1950 with the
completion of Morelos Dam, Mexico's
major diversion structure on the Colo-
rado River.
A major plan for the development of the
Upper Colorado River Basin was approved
by Congress in 1956 in a bill called the
"Colorado Source Project arid Participat-
ing Project." The Plan called for the con-
struction of several large dams, reservoirs,
and hydroelectric generating plants on the
Colorado River and its principal tributaries
above Lee Ferry, Arizona, and for an un-
defined number of "participating" recla-
mation projects within the Upper Basin.
In addition, language in the Act directed
the Secretary of the Interior to investigate
and report periodically to Congress and to
the Colorado River Basin states on water
quality conditions in the Colorado River.
Amendments concerning the study of the
River's water quality and the specifica-
tion of a schedule for reporting thereon,
were also inserted in authorizing legisla-
tion for the Navajo Indian Irrigation Pro-
ject, the initial stage of the San Juan-
Chama Project, and the Fryingpan-
Arkansas Project. These projects pro-
vided both for in basin irrigation develop-
ment and diversions out of the Colorado
River Basin. It was hoped that, with the
accumulation of basic information on
water quality and analyses of effects on
future projects, studies could be made of
ways to eliminate salinity problems. As
of 1970 the Secretary had submitted four
reports on water quality in the Colorado
River Basin.
In the fall of 1961, the salinity of the Colo-
rado River rose sharply in the water
arriving at the International Boundary
prior to its entry into Mexico. This
resulted when pumped drainage of highly
mineralized ground water had begun back
into the Colorado earlier in the year on
the Wellton-Mohawk Project in Arizona.
42
-------
These highly saline water-s from the Pro-
ject were discharged into the River down-
stream of all United States diversions, but
upstream of all Mexican diversions. The
Mexican Government immediately lodged
strong protests with the United States
Government over the River's salinity.
The United States and Mexico met to dis-
cuss the problem, and in 1965 entered
into a five-year agreement that was em-
bodied in Minute No. 218 of the Inter-
national Boundary and Water Commission.
The agreement provided for construction
and operation of a channel that would by-
pass saline drainage water from the Well-
ton-Mohawk Project around the Mexican
point of diversion at Morelos Dam. It
also gave Mexico the right to decide when
drainage water was to be bypassed, and
further provided that during the periods
of October 1 and February 28, when
Mexico was taking water at the minimum
winter rate, the United States was to
control water reaching the limitrophe
section of the river so that, without
including We lit on-Mohawk drainage
water, the flows would average the
minimum winter rate of 900 cubic feet
per second. These bypass waters were
replaced by other waters largely from
above Imperial Dam. By the end of 1971,
these operations, coupled with a gradual
improvement in the quality of Wellton-
Mohawk drainage waters, had reduced
the average annual salinity of waters
made available to Mexico to about 1, 245
parts per million TDS, with monthly ave-
rages varying from 1, 105 to nearly 1,500
ppm TDS.
Meanwhile, Mexico concluded that it could
not use waters with salinity greater than
about 1,240 parts per million TDS (1, 300
parts per million, if the Mexican method
of analysis is used in the Mexicali Valley.
The United States under terms of Minute
No. 218 agreed to bypass an additional
40, 000 to 75, 000 acre feet of Wellton-
Mohawk drainage flows annually. The
effect was to further reduce the average
salinity of water diverted by Mexico at
Morelos Dam to about 1, 160 parts per
million TDS.
Before Minute No. 218 was to have ex-
pired on November 15, 1970, the United
States proposed a new five year agree- .
ment to further reduce salinity. The
United States offered to bypass addition-
al volumes of Wellton-Mohawk drainage
and to substitute equal volumes of better
waters to reduce the average annual
salinity of waters delivered to Mexico
at the Northerly International Boundary
to about 1, 140 parts per million, TDS,
subject to increases in salinity at Im-
perial Dam. This salinity would ap-
proximate that of waters delivered to
Mexico above Morelos Dam if all United
States projects below Imperial Dam were
operating in a salt balance. Salt balance
in this context means that the same per-
centage of salt is returned to a river
from an irrigation project in drainage
as is diverted to it in irrigation waters.
The Administration of President Diaz
Ordaz of Mexico considered the pro-
posal constructive, but decided to leave
the matter to the Administration of
President Echeverria, who took office
in December 1970. Minute No. 218
43
-------
v \ • /"51*
«£€&•»*
:-.
-------
was therefore extended one year.
In 1971 and early 1972, the Government
exchanged several proposals in an attempt
to reach an agreement, extending Minute
No. 218 in November 1971 for another
year so that the discussion might continue.
After further conversations in early 1972,
Mexico requested a prompt, permanent
settlement. The Presidents of the United
States and Mexico met and issued a joint
communique on June 17, 1972. With this
communique the search for a. solution
entered another phase. The then Pres-
ident of the United States assured Pre-
sident Echeverria of his desire for a
definitive, equitable, and just solution
to the problem, announced that he was
prepared to undertake certain actions
immediately to improve the salinity of
waters delivered to Mexico, and indicated
he would designate a special represen-
tative to develop a solution and to submit
a report to him.
To immediately further improve the quality
of water delivered to Mexico above More-
los Dam, the two governments approved
a new Minute No. 241, signed July 14,
1972. It provided for the bypass of 18, 000
acre-feet of Wellton-Mohawk drainage
waters annually without charge against
the Treaty, more than twice the rate
of the United States bypass under Minute
No. 218, and a replacement by other
waters from above Imperial Dam and
from wells on the Yuma Mesa. The
operations under Minute No. 241 resulted
in reducing the average annual salinity
of waters made available to Mexico
from 1, 245 parts per million TDS in 1971
to 1, 140 parts per million TDS for the year
ending June 30, 1973. Operations under
this Minute continued until August 30,
1973, when they were terminated by pro-
visions of Minute No. 242.
In addition to the United States operations
under Minute Number 241, Mexico re-
quested the United States to bypass, with-
out replacement, the remaining drainage
wafers in the Wellton-Mohawk districts
to the Colorado River below Morelos
Dam. This additional bypass amounted
to about 100,000 acre-feet annually.
This further reduced the average salinity
of water diverted by Mexico at Morelos
Dam from 1, 160 parts per million TDS in
1971 to less than 1, 000 parts per million
TDS for the year ending June 30, 1973.
Protection of Quality under the
Water Quality Act of 1965
The Federal Water Pollution Control Act
of 1965 set forth the responsibility of the
states and the Federal Government with
respect to water quality of interstate
waters. The 1965 Act required that each
state establish water quality standards for
interstate and coastal waters within each
state.
In May 1966, the Secretary of the Interior
issued "Guidelines for Establishing Water
Quality Standards for Interstate Waters"
as directed by the 1965 Act. These Guide
lines advised the states on the contents
these standards should include necessary
for acceptance by the Secretary.
45
-------
The Guidelines stated that the purpose of
establishing water quality standards was to
"enhance the quality of water" and in no
case would standards be acceptable that
provided for less than existing water
quality. Further, a minimum of secon-
dary treatment must be achieved prior to
discharge into any interstate water re-
gardless of the water quality criteria
or uses adopted. The establishment of
standards, along with the development of
water quality criteria, and a plan for
implementation and enforcement were to
be submitted to the Secretary of the In-
terior for his approval by June 30, 1967.
Standards submitted by the State of Ne-
vada were approved without exception by
the Secretary of Interior in a letter of
June 27, 1968 to Governor Laxalt.
Development of Colorado River
Policies and Standards
In 1966, representatives of all seven Co-
lorado River Basin states met to consider
a common framework of guidelines so that
the Water Quality Standards for the Colo-
rado River System (to be set separately
by each of the seven states of the Basin)
would be mutually compatible.
The conferees did not attempt to settle
the very difficult problems of establish-
ment of numerical criteria for salinity.
Instead, it was agreed that the proposed
water quality standards should state the
criteria for salinity in qualitative terms
only, pending the acquisition of more data
and knowledge. The conferees finally
agreed on January 13, 1967, to a docu-
ment entitled "Guidelines for Formula-
ting Water Quality Standards for the Inter-
state Waters of the Colorado River Sys-
tem".
Based upon the Guidelines, all basin
states adopted policies and standards for
the Colorado River and submitted them to
the Secretary of Interior.
On August 26, 1969, the Nevada State Board
of Health adopted water quality standards
applicable to Las Vegas Wash. Since the
Wash is an intrastate stream, these stan-
dards are not subject to Federal approval.
The standards establish two sets of water
quality criteria, an interim set to take
effect in 1973 and more stringent require-
ments to take effect in 1980.
In December 1971, the United States
Environmental Protection Agency insti-
tuted a 180-day enforcement action against
the major polluting municipalities and in-
dustries who were discharging waste water
into Las Vegas Wash. At the same time
the Nevada Legislature enacted a law which
would have the practical effect of preven-
ting the construction of these subdivisions
after July 1973 unless the pollution was
abated. The local Interim-Agency Water
Pollution Control Task Force and the
Colorado River Commission of Nevada
previously studied the problem, but were
not in power to implement a solution.
In 1971, the Nevada legislature designated
the Las Vegas Valley Water District as
the agency responsible for developing and
46
-------
WATER QUALITY STANDARDS
LAS VEGAS WASH
CONTROL POINT
North Short Road (No sampling will bt required upstream of the control point if the regulations art satisf itd at the coatrol pent.
TEMPERATURE °C
Monthly Mtai June I to September 30 Not more thai 27*
' ' October I to Moy 31 Hot more thai 23°
Single Volue in 90% of samples- • • June I to September 30 Not more thai 31°
• • " " • . . . October I to May 31 Notmortthoi 27°
pH UNITS
Monthly Median Within rang* 6.5 - 1.5
Single Value in 90% of samples- • Within rang* 6.5 - 8.5
DISSOLVED OXYGEN - ma/I
Monthly Mian Hot IMS thai 5.0
Single Value in 90% of samples Not lets thai 4.0
BOD5 - ma/I
Monthly Mean Not nor* thai 10.0
Single Value in 90%of templet Not nor* thai 15.0
COD-ma/1
Monthly Mtan Not more thai 40.0
Single Valut in 90% of samples Not more thai 50.0
SS-mg/l
Monthly Mean Not more thai 2.0
Single Value in 90% of samples Not more than 5.0
MBAS-mg/1
Monthly Mean Not more thai 0.8
Single Value in 90% of samples Not more thai 1.0
PHOSPHORUS AS P - mg/l
Monthly Mean Not man that 0.5*
Single Value in 90 % of samples Not more thai 1.0*
*But not to exceed 400 pounds/day during April through October
TURBIDITY - JTU
Monthly Mean Not more than 5.0
Single Value in 90% of samples Not more thai 10.0
FECAL COLIFORM - The fecal coliform concentration, based on a minimum of 5 samples during o»y
30-day period, shall notexcttd a geometric mean of 200 per 100 milliliters.nor
shall more than 10% of total samples during any 30-day period exceed 400
per 100 milliliters
The beneficial uses to be protected in the Las Vegas Wash are as follows: pith and wildlife, esthetics,
irrigation and stock watering and recreation.
SOURCE* State of Nevada, Water Pollution Control Regulations, adopted by the State Environmental
Commission on October 24, 1973.
table 1
-------
implementing a plan for abating the pol-
lution caused by waste water flow in Las
Vegas Wash. In accordance with the
district directives of that legislation, the
district prepared a plan and submitted it
to the Nevada legislature in December
1972.
The Nevada State Legislature approved
the 1972 final written report of the Las
Vegas Valley Water District, which out-
lined a program for export of polluted
waters to the Dry Lake area. The legis-
lators' response came in the form of
Senate Bill 288 which directed: a) the
Board of County Commissioners to make
a review of the program proposed in
December 1972; b) complete the review
by September 1, 1973 and recommend
a course of action to the Legislative
Committee and the Governor of Nevada;
c) after approval by the appropriate
authorities, the Board of County Com-
mit sioners were authorized to construct
the project through the issuance of state
supported bonds provided that the Federal
Government provide at least 50% of the
financing required.
Colorado River Basin Salinity
Control Act
authorize the construction, operation,
and maintenance of certain works in
the Colorado River Basin to control
the salinity of water delivered to users
in the United States and Mexico. Sec-
tion 202, Part IV of the proposed legis-
lation identifies the Las Vegas Wash unit,
Nevada, as consisting of "Facilities for
collection and disposition of the falling
ground water of Las Vegas Wash. . . "
The potential for facilities identified in
this proposed legislation emphasizes the
relationship of the proposed Las Vegas
Wash/Bay Pollution Abatement Project
to areawide planning at Federal, State,
and local levels.
Present Water Quality Standards
Water Pollution Control Regulations
(WPCR), for the waters of the State
of Nevada were adopted by the State
Environmental Commission on Octo-
ber 24, 1973. Existing standards for
the state include the revisions adopted
April 10, 1973, June 26, 1973, and
those of October 24, 1973. The Octo-
ber 24, 1973 standards were approved
with one exception by the U.S. Environ-
mental Protection Agency on November
30, 1973.
The Colorado River Basin Salinity Con-
trol Act, introduced into the U.S. Con-
gress as HR 121 65 on January 21, 1974,
was developed in response to the need
for a definitive solution to the interna-
tional salinity problem in the Colorado
River. This Bill, if adopted, would
The one exception to EPA's approval
of the October 24, 1973 Water Pollution
Control Regulation was the temperature
criterion for Las Vegas Wash. A stan-
dard for temperature was included as
one of the ten proposed amendments which
accompanied EPA's approval of the Octo-
48
-------
ber regulations. On April 9, 1974, after
continuing discussion of an acceptable
temperature standard, the State Environ-
mental Commission adopted a temperature
standard that will be included in the State
regulations if approved by EPA. The
October 24, 1973 WPCR and the April 9,
1974 revisions to the regulations are
shown in Appendix C.
The U.S. Environmental Protection
Agency along . with its approval of the
Nevada Water Pollution Control Regula-
tions' proposed amendments to 40 CFR
120, "Interstate and Intrastate Waters
of the State of Nevada. " Two of the ten
proposed amendments are particularly
relevant to the evaluation of any pre-
sently proposed project alternative.
As noted above, discussions on the
proposed amendments continued, and on
April 9, 1974, the State Environmental
Commission adopted revisions to the
State regulations. These State-adopted
revisions were essentially the same as
those proposed by EPA.
Among the original amendments proposed
by EPA was the salinity standard for Las
Vegas Wash. On March 28, 1974, in a
letter to the Governor of Nevada, the
EPA Regional Administrator elected to
hold the salinity standard in abeyance
pending the conclusions of negotiations
with the Colorado River Basin Salinity
Control Forum. Thus, there is not
presently a numerical salinity standard
for Las Vegas Wash.
Quality of Las Vegas Water Supplies
The present quality of the Valley's three
major water resources is shown in
Tables 2 through 5. All three resources
are characterized by water hardness and
by moderate to high salinity concentra-
tions. With little doubt, the ground water
resource affords the highest quality
water, followed by Colorado River Water
and last by waste water.
The future quality of the Valley's ground-
water resources might be expected to re-
main fairly constant. However, lawn and
landscaping irrigation in the Valley using
water of higher salinity than the ground
water, could result in some degradation
of the deeper, better quality ground water
resources by downward migration through
the low permeability aquitards. Ground-
water recharge programs using reclaimed
waste water could have either beneficial
or detrimental effects upon the quality of
the ground-water resources, depending
upon the character of the recharged water.
These effects would depend for the most
part upon the level of treatment provided
prior to recharge.
Colorado River Water
The quality of Colorado River water is
acceptable but not as good as that of the
ground water. It is harder and has a
higher concentration of TDS. Water
quality records for the Colorado River
show that annual average TDS at Hoover
49
-------
WATER QUALITY CHARACTERISTICS
LAS VEGAS VALLEY WATER SUPPLIES
PARAMETER
CALCIUM as Co
CHLORIDE as C»
FLUORIDE as F
IRON as Fe
MAGNESIUM as Ma
NITRATE as NO 3
SODIUM and POTASSIUM as Na and K
SULFATE as S04
ALKALINITY as CaCOs
BICARBONATE as HC03
CARBONATE as CO 3
HARDNESS as CaCOj
COLOR
ODOR
PH
TOTAL DISSOLVED SOLIDS
TURBIDITY
UNITS
mg/l
mg/l
mg/1
mg/l
mg/l
mg/l
mg/l
mg/l
mg/l
mg/l
mg/l
mg/l
TON
value
mg/l
JTU
LAKE MEAD©
RANGE
86-94
86-96
.33 -.68
0-.05
23-32
.2-2.1
102-122
290-345
100-111
122-135
316-365
NA
2-4
7.7-8.2
722-781
.I8-.35
AVERAGE
90
92
0.5
.02
27
I.I
109
320
106
129
__ Mm
335
5.0
3
7.9
745
.24
SNWP®
RANGE
86-90
88-96
.35-J5
0-.03
23-32
.2-1.7
105-133
290-365
105-108
128-132
i r t n i F ...
311-349
0-<5
NA
7.8-8.2
737-755
.02 -.08
AVERAGE
87
92
0.5
J02
27
I.I
113
326
107
130
330
<5
1.4
8.0
746
.05
GROUNDWATER©
RANGE
30-60
0-10
.2-1
O-.l
20-40
5-15
10-50
30-100
150-240
180-280
0-12
190-290
0-5
NA
7.5-7.8
200-400
.03-1.6
AVERAGE
55
<5
.4
JQ2
30
6
30
65
170
210
-------
HISTORIC WASTEWATER CHARACTERISTICS
WWTP EFFLUENT
CITY OF LAS VEGAS
EFFLUENT PARAMETER
SUSPENDED SOLIDS
BOD 5
COD®*
P04 as P
NH3 as N
TDS
ALKALINITY as CaC03
HARDNESS as CaCOj
CALCIUM as Co
TEMPERATURE (INFLUENT)
PH
CHLORINE RESIDUAL
LAS
1 IMITO
UNITS
mg/l
mg/l
mg/l
mg/l
mg/l
mg/l
mg/l
mg/l
mg/l
°C
mg/l
mg/l
1971
RANGE
15-29
7-26
NC
7.0-9.9
14-21
820-1000
220-290
312-372
61-78
17.8-25.6
7.6-7.8
1.0-1.0
i ic
m
AVERAGE
18
20
DAT
9
17
898
246
338
71
22.7
7.7
1.0
) DAT
1972
RANGE
14-28
12-29
\ AVAILAB
7.0-93
12-22
977-1080
220-269
340-400
62-83
17.2-27.2
7.6-7.7
1.0-1.0
A AVAILAB
i
AVERAGE
21
18
_U -T— "•"
9
18
1006
241
377
74
21.1
7.6
1.0
1973
RANGE
13-29
10,21
6.4-9.3
15-23
1027-1073
210-266
340-535
62-%
17.2-27.2
7.5-7.7
1.0-1.0
AVERAGE
18.4
14.7
9
18
1058
247
413
80
22.7
7.6
1.0
)*COD- Range 100-120 mg/l, Average 110 mg/l December 1968 Tests by Boyle-CH2M.
SOIIRCF* Based on w«tewater Plant Records for CLV WWTP and
ovuuvb- N6Va(j0 power company's sunrise Power Station.
table 3
-------
HISTORIC WASTEWATER CHARACTERISTICS
WWTP EFFLUENT
CLARK COUNTY SANITATION DISTRICT
EFFLUENT PARAMETER
SUSPENDED SOLIDS
BOD5
COD
P04 as P ©
NH3 as N
TDS
ALKALINITY as CaCOa
HARDNESS as CaCOj
CALCIUM as Ca©
TEMPERATURE (INFLUENT)
PH
CHLORINE RESIDUAL
LAS
UNITS
mg/l
ma/I
rag/I
m^/l
mg/l
mg/l
mg/l
mg/l
mg/l
«C
mg/l
mg/l
1971
RANGE
15-30
18-43
83-130
7.3-9.1
1 1.7-17.7
1244-1680
213-258
528-658
89-145
24-30.1
7.0-7.5
1.0-1.9
0.6-1.5
AVERAGE
25
26
99
8.2
14.7
1496
234
602
119
27.4
7.2
1.4
I.I
1972
RANGE
18-48
13-58
71-186
7.3-9.5
1 1.5-18.7
1545-1853
214-240
501-706
96-136
22.5-29.1
7.4-7.6
1.6-4.2
0.7-1.9
AVERAGE
30
26
108
8.2
15
1666
223
622
121
26
7.5
2.9
1.2
1973
RANGE
18-80
19-40
88-242
9.5-13.4
14.7-18.9
1706-1934
220-252
501-589
78-153
21.5-28.8
7.5-7.6
1.5-3.3
1.0-2.9
AVERAGE
38
30.5
128
10.7
16
1831
236
546
124
25.2
7.5
2.4
2.3
OBUM
©Represents ortho-phosphates only for 1971 and 1972; 1973 measurements are for total phosphates as
determined after April 1973.
0 From Desert Research Institute records of station LW027.
SOURCE* Based on Wostewater Plant Records for CCSO WWTP.
table 4
-------
HISTORIC WASTEWATER CHARACTERISTICS
WWTP EFFLUENT
CITY OF HENDERSON
WWTP NO. 1 AND WWTP NO. 2
EFFLUENT PARAMETER
SUSPENDED SOLIDS
BOD 5
COD
P04 as P
NH3 as N
TDS
ALKALINITY as CaC03
HARDNESS as CaCOs
CALCIUM as Ca
TEMPERATURE (INFLUENT)
pH
CHLORINE RESIDUAL
LAS
I HIITC
UNITS
mg/l
mg/l
mg/l
mg/I
mg/l
mg/l
mg/l
mg/l
mg/l
°C
mg/l
mg/
1961
RANGE
35-137
NA
104-169
4.5-5.0
NA
4148-4920
NA
NA
NA
NA
NA
NA
NA
WWTP
3©
AVERAGE
86
30
137
4.8
10.9
4534
NA
NA
NA
NA
NA
NA
NA
NO. 1
1971©
AVERAGE
59
85
NA
NA
10.9
NA
NA
850
NA
NA
7.4
NA
NA
1973®
AVERAGE
NA
NA
NA
NA
NA
2293
319
825
305
NA
7.2
NA
NA
^•••^MVMMMB^MM
WWTP
1971©
AVERAGE
283
133
NA
NA
10.4
NA
NA
340
NA
NA
8.0
NA
NA
iHMBMHHMHHHMHHHMl
NO. 2
1973©
AVERAGE
NA
NA
NA
NA
NA
1000
240
270
100
NA
7.4
NA
NA
No Data Available
SOURCES: © A Comprehensive Water Quality Control Program for the Us Vegas Drainage Basin-Phase I, February 1969 by Boyle Engineering and
(T) Analysis by Clark County Sanitation District Laboratory in August 1971.
©Analysis by Atlas Chemical Testing Laboratories, Inc. letter of May 1,1973.
table 5
-------
Dam has increased from 671 mg/1 in
1960 to 745 mg/1 in 1973. Efforts are
currently underway by the seven Colo-
rado River Basin States and the Bureau
of Reclamation to institute a program
which has as its objective, maintenance
of TDS levels in the lower main stream
of the Colorado River at or below 1972
levels. If this is accomplished, the
future quality should be essentially
the same as that shown for 1973 on
Table 3-7.
Reclaimed Waste Water
For the most part, the waste water re-
sources of Las Vegas Valley may be ,
characterized as high quality secondary
waste water plant effluents.
The City of Las Vegas1 and the County's
trickling filter treatment plants presently
treat 96% of the waste water flow being
considered for reclamation. The City of
Henderson's waste water plants contribute
the remaining 4% of Las Vegas Valley's
present waste water resource.
The results of recent analyses of treat-
ment plant effluents from the City of
Las Vegas, the Clark County Sanitation
District and the City of Henderson are
presented in Tables 3, 4 and 5, res-
pectively.
The information on the City of Las Vegas
plant and the Clark County plant repre-
sents the range of qualities experienced
and yearly averages based on plant re-
cords of tests conducted. The informa-
tion presented for the City of Henderson
is incomplete. The parameters listed
are based on limited grab samples.
Henderson's waste water flow has, and
probably will continue to have, only a
negligible effect on the overall charac-
teristics of the combined flow.
The Tables demonstrate that two trickling
filter plants operated by the City of Las
Vegas and the Sanitation District are
accomplishing a high degree of treatment
and are producing good quality effluents.
Table 5 indicates that the City of Hen-
derson is experiencing difficulty in pro-
ducing an adequately treated secondary
effluent. Henderson is presently refur-
bishing and remodeling its facilities in
order to improve the quality of effluent to
a level comparable to that now produced
by the other waste water treatment
plants.
It is believed that such secondary effluent
parameters as; biochemical oxygen demand
(BOD), suspended solids (SS), chemical
oxygen demand (COD), phosphorous and
nitrogen (PO4 as P and NH3 as N) will
not significantly change between now and
the year 2000. However, as the water
supply in the Valley becomes more depen-
dent upon the Colorado River, it is
expected that there will be increases in
the concentrations of calcium, chloride,
sulfate, sodium and potassium.
Many homeowners, hotels, casinos and
54
-------
commercial establishments in the Valley
have softening units or purchase partially
demineralized bottled drinking water.
It is believed that waste brine waters
from, softener regenerations frequently
find their way into the waste water col-
lection and treatment facilities, thus,
accounting in part for the high concen-
trations of total dissolved solids noted
in Valley waste water treatment plant
discharges. The Clark County Sanita-
tion District and the City of Las Vegas
will soon undertake studies to locate
and quantify sources of high TDS inflow
to their respective waste water systems.
Concentration projections of individual
chemical constituents have not been
made. There are, however, indications
that if no corrective action is taken, the
salinity (TDS) of the combined City of
Las Vegas and County Sanitation Dis-
trict plant effluents may reach about
1600 mg/1 by 1980, 1800 mg/1 by 1990,
and 1990 mg/1 by the year 2000.
Colorado River Basin
The water quality in the Colorado River
declines markedly between its origins
in the Rocky Mountains and the Inter-
national Border to Mexico. The rea-
sons for poor quality water arise from
both natural and man-made sources.
The most important sources of salt loads
in the Colorado River Basin are from
natural sources which account for about
2-1/3 of the average annual salt load
passing Hoover Dam. Surface runoff,
including ground water inflow comes in
contact with the soil and picks up min-
eral salts from the surrounding drainage
area and then flows into the Colorado
River System. These are called dif-
fused sources and come primarily from
several relatively small areas, such as
Paradox Valley in the Upper Basin.
They account for about half of the salt
burden in the entire Colorado River
Basin. Discrete or point sources also
add saline water to the system from
mineral springs that occur throughout
the Basin. Mineral springs add more
salt to the Colorado River in the Lower
Basin than any other type of salinity
source. Blue Springs, the largest
point source of salinity in the entire
river basin, is located near the mouth
of the Little Colorado River and contri-
butes salt loads of about 547, 000 tons
each year, or about 5% of the annual
salt load at Hoover Dam.
There are also major contributions by
Dotsero and Glenwood Springs which
produces a total of 518, 000 tons of salt
each year. (Las Vegas Wash contributes
150, 000 tons of salt each year. )
The major man-made source of salinity
to the river is from irrigation. Muni-
cipal and industrial sources of salinity
that are found in flows such as the Las
Vegas Wash only contribute about 1%
of the average salt load at Hoover Dam
each year. A summary of salt load
distribution can be found in Table 6.
In the Environmental Protection Agency's
report, "The Mineral Quality Problem in
the Colorado River Basin" a projection is
55
-------
made of future average salinity concen-
trations in mg/1 based on initial base
concentrations in i960. The table shown
below is divided into two categories:
unlimited vs. limited development condi-
tions. The first category details salinity
projections on the basis that no limits
would be placed on future water resources
development other than those applicable
under existing water laws. The second
category was based on the possible limi-
tations of future water resource develop-
ment in the Basin.
Environmental Protection Agency,
"Report on Pollution Affecting Las Vegas
Wash, Lake Mead & The Lower Colorado
River, Nevada-Arizona-California" ,
the average discharge of dissolved
solids (TDS) by the Las Vegas Wash
into Lake Mead was 150, 000 tons per
year or about 411 tons per day. This
report also indicated that these contri-
butions increased from 10 mg/1 and
12 mg/1 in the TDS concentrations at
Hoover and Imperial Dams, respectively.
Comparison of Salinity Projections
Unlimited Development
Conditions
Location
Hoover Dam 697
Parker Dam 684
Palo Verde Dam 713
Imperial Dam 759
1980
876
866
940
1056
2010
990
985
1082
1223
Limited Development
Conditions
1970 1980 & 2010
760 800
760 800
800 850
865 920
The discharge of waste water into Las
Vegas Wash has produced flows of excep-
tionally high TDS, and, according to a re-
port by Hoffman, Tramutt and Holler, an
average of 4.48 tons per acre-foot en-
tered Lake Mead during their sampling
period in 1968. This figure can be
compared with the 1968 average TDS
of Colorado River water measured in
the Grand Canyon equal to . 91 tons per
acre-foot. In another report by the
If all flow from Las Vegas Wash were
terminated and did not enter the Colorado
River System at another location, then
the salt load could be expected to de-
crease by approximately 409 tons per
day below Hoover Dam and approxi-
mately 363 tons per day at Imperial
Dam. The present increase in TDS con-
centrations that result from flow out
of Las Vegas Wash caused an economic
loss, according to the applicant, of
$670, 000 per year to the regional
56
-------
Summary of Salt Load Distributions
V •
i
A
Source
Salt Load (1,000) T/Yr.
tipperLowerAbove
Basin Basin Hoover Dam
Natural Diffuse
Sources 4,400 1,400 5,760
Natural Point
Sources
Irrigation
Municipal and
Industrial
Total
510
3,460
50
770
420
100
1,280
3,540
150
6,420 2,690 10,730
Percent of Total Load
Upper Lower Above
Basin Basin Hoover Dam
52.2 52.1
6.1
41.1
28.6
15.6
0.6 3.7
100.0 100.0
53.7
11.9
33.0
1.4
100.0
57
-------
economy in Arizona and Southern Cali-
fornia. Inclusive in this impact is the
savings that would result from agricul-
tural concerns who would use water from
the Colorado River of a lower salinity
and thus incur a beneficial impact on
crop yields and the corresponding cost
of operation.
In addition to dissolved solids concentra-
tion, the Colorado River is also subject
to increased concentrations of nitrogen
and phosphorus which act as nutrients
that support algae blooms.
flows. Warmer temperatures can reduce
the amount of dissolved oxygen in the
water and as a result will have an ad-
verse affect on fish life. High tempera-
tures can also increase the rate of
chemical reactions in addition to the
rate of growth and decomposition of
organic matter resulting in bad odors
and tastes.
Water temperatures leaving Hoover Dam
fluctuate very little. Data for 1941 to
1968 indicates average monthly tempera-
tures ranging between 54° and 58° F.
Within Lake Mead, substantially larger
concentrations of algae can be found in
the area near the mouth of the Las Vegas
Wash in addition to correspondingly
larger concentrations of nitrogen and
phosphorus. In tests by the Federal
Water Quality Administration (EPA)
during 1970, Colorado River waters in
Lake Mead, upstream from Las Vegas
Bay, were slightly lower in algae growth
potential than they were after release
from Hoover Dam.
Another important parameter to consider
when discussing water quality in the Colo-
rado River Basin is temperature. Tem-
perature fluctuations within the River can
vary from freezing to above 90°F.
These changes are primarily due to natu-
ral climatic conditions; however, other
influences include upstream releases
from reservoirs affecting downstream
temperatures, thermal springs, waste
water discharges and irrigation return
Salinity Control
Four salinity control projects would be
authorized for construction under the
Colorado River Basin Salinity Control
Act that will benefit water users in the
United States and Mexico. These pro-
jects would achieve the near-term objec-
tive of EPA and the seven Colorado River
Basin States by removing 514, 000 to
594, 000 tons of salt annually. The four
projects are:
1. Paradox Valley, Colorado: A 14,000
foot thick, pure salt dome is within six
feet to 100 feet of the ground surface.
Rising ground water picks up over 200, 000
tons of salt per year. The project plans
to lower groundwater by well pumping and
transporting brines to an evaporation
reservoir for disposal. Estimated salt
removal is 108, 000 tons per year which
will reduce salinity at Imperial Dam by
20 ppm in the year 2000.
58
-------
2. Grand Valley, Colorado: About 80,000
acres of land are irrigated in the valley.
The soils are derived from Munco Shale
which have a high salt content. Return
flows from agricultural lands are esti-
mated to contain 500,000 tons per year
of salt. The Grand Valley salinity con-
trol project would include: a) improved
irrigation management methods such as
scheduling times and amounts of water
to apply, b) lining drainage canals and
laterals to reduce seepage, and c) on-
farm improvements such as measuring
and control devices and installation of
proper drains. Estimated salt load
reductions are expected to be 2,000 to
280, 000 tons per year with a subsequent
reduction of TDS at Imperial Dam of 23
to 32 ppm by the year 2000.
3. Crystal Geyser, Utah: The Crystal
Geyser is an abandoned oil test well
which erupts periodically. The water
has a TDS of 11, 000 to 14, 000 ppm and
contributes 3, 000 tons of salt per year
to the River. The project plan would
construct a dike around the geyser and
drain in the water to an evaporation pond.
Estimated salt removal is 3,000 tons per
year and would reduce salinity at Im-
perial Dam by 0. 3 ppm in the year 2000.
4. Las Vegas Wash, Nevada: The Wash
adds about 150, 000 tons of TDS per year
to the Colorado River System. Sources
are both point and diffused and contribute
approximately 20% and 80% of the total,
respectively. Rising ground water
(discussed further under the next heading)
over long established gro'undwater mounds
beneath the industrial waste ponds and
other discharges constitute the diffused
source. The proposed project plan would
collect ground-water flow by subsurface
drains and pump the water to evaporation
ponds. Estimated salt load reduction is
94, 500 tons per year, which would re-
duce TDS at Imperial Dam by 13 ppm.
Other potential salinity control projects
are shown in Figure 11.
Water Quality in Las Vegas Bay
Water quality conditions in the Las Vegas
Bay portion of Lake Mead have been der
clining noticeably during the past 20 years.
A study conducted in the late 1940's and
1950's by Nevada's Department-of Fish
and Game indicated no evidence of pollu-
tion except for one unexplained fish kill
in 1953 and an unusual reduction in the
water's transparency caused by a large
algae bloom in 1952 (Nevada Fish and
Game, 1953).
Through the years, as more and more
nutrients and dissolved solids were
discharged into Las Vegas Bay, the
more severe the pollution problems
became. Within the last few years
algal growth and blooms have risen to
levels resulting in a. substantial reduc-
tion of water quality and have at times
reduced the recreational attractiveness
of the area.
Many studies have been conducted to de-
59
-------
LEGEND
k SALT LOAD REDUCTION PROJECT
IRRIGATION IMPROVEMENTS
HENRY'S FORK
ASHLEY CREEK
DUCHESNE AREA
BIG SANDY CREEK
GUNNISON
LAXVERKii
ROjIcf
PAHGRE
AREA
figure 11
-------
n
UJ
x>
[fl
t/3
00
f-UJ
O <->
< CO
i5
o—
I- CO
< c/y
o __ ,
UJCO
O Q
gj
LUO
Q
UJ
UJ
ESTIMATED AVERAGE DAILY TONNAGE OF
TOTAL DISSOLVED SOLIDS (SALTS ) DISCHARGED
TO LAS VEGAS WASH AND TO LAS VEGAS BAY OF LAKE MEAD
600
500
400
300
200
100
\'if\ Vifs
CALENDAR YEAR ENDING DECEMBER 31 'r
LEGEND:
O COMBINED DISCHARGES TO LAS VEGAS WASH FROM THE CITY AND
COUNTY WASTEWATER, TREATMENT PLANTS.
A DISCHARGES FROM LAS VEGAS WASH TO LAS VEGAS BAY OF LAKE
MEAD AS ESTIMATED FROM DATA COLLECTED AT THE NORTH SHORE
ROAD GAGING STATION.
DATA SOURCE:
I.) RECORDS OF THE DESERT RESEARCH INSTITUTE, LAS VEGAS, NEVADA.
2.) RECORDS OF THE U.S. DEPARTMENT OF INTERIOR, GEOLOGICAL SURVEY,
CARSON CITY, NEVADA;
3.) RECORDS OF THE UNIVERSITY OF NEVADA, LAS VEGAS, NEVADA ( Dr. JAMES DEACON)
4.) RECORDS OF THE CITY AND COUNTY WASTEWATER TREATMENT PLANTS.
figure 12
-------
DISCHARGES TO LAKE MEAD I
TDStAwrogi): 3,360 mg/l
TDSlA»rao«)= 1,176,900 Ib/doy
0-0 2 mod
Mi',' Vl'ill rn,/
0-8 5 mgd
TDS= 7,000 mg/l
IDS =379.500 Hi/*
O'Ofmjd
TDS= 3,560 mg/l
TDS= 20,80016/doy
IROUNI IKATI
INFLOW BELOW
HENDERSON
LANDFILL
0=27C mgd
TDS= 1(058 mVl
BMI TAILING PONDS
9>3.3ntd
rDS=6,000 mg/l
„
POWER
PLANT
f- 3,600]
I Ib/doyJ
FROM
LAS VEGAS
VALLEY
UNDESCRIBED
POINT AND DIFFUSE
SOURCES
CLARK
POWER
PLANT
-14,300
Ib/to
0-90mgit
DS= 1,831 mg/
TDS=I37,400W*!>
Q=07-09m«d
IDS-2,293 mg/l
TDS= 15,300 Ib/doy
0=09
TDS=l,05(riig/l
TDS = 7,900 Ib/doy
S= 2 3mgd
TDS=l,83lmg/l
TDS-M.IOO Ib/doy
' ' ' Rl i .,
FROM
HENDERSON
AREA
LAS
VEGAS
WWTP
1.21,20
I lb/do»
O'J.Ingd
TDS--I.058 mg/l
TDS=29,100ID/
BMI
INDUSTRIAL
COMPLEX
Qtl.tngd
TCS=I,83I mg/l
TDS= 27,500 ll/doi
TDS=9l7mg/l
TDS:2IO,3Wlb/do
,366 mg/l
DS=l99,400lWo»
LAS VEGAS
AND
NORTH LAS VEGAS
UNINCORPORATED
AREA
{
mg/l
••• i
o
LE6END
POINT SOURCE DISCHARGE
DIFFUSE SOURCE DISCHARGE
EVAPORATION AND/OR TRANSPIRATION
PHREATOPHYTES
HYDROPHYTES
WASTEWATER TREATMENT PLANT
BASIC MANAGEMENT INC
TOTAL DISSOLVED SOLIDS
MILLIGRAMS PER LITER
MILLION GALLONS PER DAY
COMPUTED FROM MEASUREMENTS AT
NORTH SHORE ROAD
NET AFTER EVAPOTRANSPIRAIION FOR
PHREATOPHYTES BELOW HENDERSON
LANDFILL
YEAR 1973
POINT AND DIFFUSE
DISCHARGES
TO
LAS VEGAS WASH
62
-------
WASTE BRINE
Q--8 mgd
TOS= 500 mg/l
TDS=33,400lb/dQ¥
IDS: 4,100 mg/l
rDS=l,700lb/dm
0=46 6 n.
TDS = 1,280 mg/l
TDS=5B,800lb/
0=0 14 mgd
TDS = 4,200 Jig/l
TDS--4.900 lb/da»
= 34mgd
= 2,330mg/l
TOS=66,IOOic/*i
Q=2 3 mgd
TDS=l,400mg/l
TDS=26,800lb*iy
0=lmgd
TDS = 1,400 mg/l
TDS=ll,700lbAiH
0= 7 mgd
TDS=i,400 mg/l
TDS=8,200lb/doy
CLARK
COUNTY
WWTP
[,53,3001
0- 3 3 mgd
fDS= 1,400 mg/l
Q=32 mgd
TDS=l,280mg/l
TTJS=MI,600I
0=22 I mgd
TDS=I,280 mg/l
0= 42 6 mgd
TDS=l,250mg/l
TDS=444,IOO in/dot
Q= 3 4 mgd
TDS=2,l80mg/l
WWIP
- ft
rs
m«/l
,
LF6END
POINT SOURCE DISCHARGE
DIFFUSE SOURCE DISCHARGE
EVAPORATION AND/OR TRANSPIRATION
CHREATOPHYTES
HYDROPHYTES
WASTEWATER TREATMENT PLANT
ADVANCED WASTEWATER TREATMENT
TOTAL DISSOLVED SOLIDS
MILLIGRAMS PER LITER
MILLION GALLONS PER DAY
NET AFTER EVAPOTRANSPIRATION FOR
PHREATOPHYTES BELOW HENDERSON
LANDFILL
(T) FROM LAS VE VALLEY •
0 = 94mjd
TDS • 6,000 mg/l
TDS = 470,500 lt>/da>
?) UN SCRIBED POINT
Q = 73mgd
TDS = 6,000 mg/l
TDS = 365,400lb/dOf
(?) UNDERFLOW FROM HENDERSON AREA -
0= 54 mgd
TDS = 1,500 mg/l
TDS=42,500U>/doy
0 GROUNDWATER INFLOW BELOW HENDERSON LANDFILL -
8 = 0 3 mgd "
TDS =5,800 mg/l
TOS = I4,500 Ib/doj
YEAR 2000
POINT AND DIFFUSE
DISCHARGES
TO
LAS VEGAS WASH
-------
ESTIMATED ANNUAL AVERAGE DAILY PHOSPHOROUS DISCHARGES
TO LAS VEGAS WASH AND TO LAS VEGAS BAY OF LAKE MEAD
3,000
2,000
1,000
CO
£l
7
1969 1970 1971 1972
CALENDAR YEAR ENDING DECEMBER 31st
LEGEND:
O COMBINED DISCHARGES TO LAS VEGAS WASH FROM THE CITY AND
COUNTY WASTEWATER TREATMENT PLANTS.
A DISCHARGES FROM LAS VEGAS WASH TO LAS VEGAS BAY OF LAKE
MEAD AS ESTIMATED FROM DATA COLLECTED AT THE NORTH SHORE
ROAD GAGING STATION.
DATA SOURCE:
I.) RECORDS OF THE DESERT RESEARCH INSTITUTE, LAS VEGAS, NEVADA.
2.) RECORDS OF THE U.S. DEPARTMENT OF INTERIOR, GEOLOGICAL SURVEY,
CARSON CITY, NEVADA.
3.) RECORDS OF THE UNIVERSITY OF NEVADA, LAS VEGAS, NEVADA ( Dr. JAMES DEACON).
4.) RECORDS OF THE CITY AND COUNTY WASTEWATER TREATMENT PLANTS.
figure 15
-------
ALGAL COUNT vs. TOIAL PHOSPHOUUUS
IN LAS VEGAS BAY OF LAKE MEAD
100,000
10,000
o
u>
—
z
73
o
o
1,000
100
+
•'
-O-
T
- i --
.001
O.O1
0.1 C
TOTAL PHOSPHOROUS as P-mg/l
LEGEND:
O INNER BAY
A MIDDLE BAY
O OUTER BAY
f COMPOSITE OF ENTIRE L.V. BAY
DATA SOURCE:
"FINAL REPORT ON LAS VEGAS BAY OF LAKE MEAD TO LAS VEGAS VALLEY WATER DISTRICT
BY UNIVERSITY OF NEVADA, LAS VEGAS, Dr. JAMES DEACON AND Dr. RICHARD TEW AUTHORS
SPRING 1973.
NOTE: CURVES BASED ON 204 LAKE SAMPLES TAKEN 5-1-72 THRU 10-16-72.
figure 16
"J\
-------
termine the cause and extent of this
problem. Conclusions drawn from these
studies indicate that the primary problem
is the effluent from Las Vegas Wash,
which is high in nutrients and dissolved
solids. Algal growth resulting from the
increased availability of these nutrients,
especially phosphorous, will produce ob-
jectionable aesthetic conditions. If these
conditions are allowed to persist, they
could eventually affect the quality of the
area's recreation and pose a public health
hazard. Studies conducted in 1972 and
1973 by Dr. James Deacon, indicate that
plankton populations increase in Las Vegas
Bay during the warm summer months.
During this period, the upper water
layers of the Bay are considered mildly
eutrophic or nutrient-rich. This is in
contrast to the oligotrophic (characteri-
stic of a deep lake having low nutrient
concentration) conditions which occurred
during most of the year (Las Vegas Valley
Water District, 1972).
In order to better understand the inter-
relationship between Las Vegas Wash
discharges and water quality and algal
populations in Las Vegas Bay, a county-
funded monitoring study will be conducted
on a continuing basis by Dr. Deacon
and his staff. This program will involve
the establishment of eight sampling sta-
tions including one at North Shore Road,
one in the channel at the head of Las
Vegas Bay, the mouth of Las Vegas Bay
(3 stations), one above Hoover Dam, one
below Boulder Canyon and one at the
Boulder Basin. At these stations the
following parameters will be analyzed:
number and kinds of phytoplankton per
mililiter, chlorophyll content in mili-
grams per cubic meter, dissolved and
total phosphorus, nitrate, nitrogen, and
turbidity in Jackson turbidity units. Ad-
ditional measurements will include tem-
perature, conductivity, dissolved oxygen,
pH, COD, coliform count, total free chlo-
rine, BOD, and methylene blue active
LAS VEGAS APPLIED IRRIGATION WATER AND
RETURN'FLOW TO THE NEAR-SURFACE AQUIFER - 1973
Type of Irrigation
Golf Courses
Crop Irrigation
Residential, Public and
Commercial
TOTAL
Applied Water
(Ac-Ft)
7,468
7,156
33,372
47, 996
Return Flow
(Ac-Ft)
3,357
3,693
21,624
28,674
66
-------
NORTH SHORE ROAD
) •*—«US VEGAS WASH
LAKE HEAD
BOULDER
BEACH
+a BOULDER
Q ISLANDS
WATER LEVEL
INNER BAY
MIDDLE BAT
OUTER BAY
TOTAL
SURFACE AREA OF EAY
(SQUARE FEET)
1150'
29.0 X I06
45.4 X I06
140.3 X 10'
3I4.7XI06
1200'
51.0 X I06
68.2X I0€
171 6X 10 •
290 B XIO8
VOLUME OF BAY
(CU3IC FEET)
1 150'
0.5 X 10'
2.3 XIO*
132 XIO'
16 0 XIO*
1200'
2.5X10*
51 XIO'
210X10'
28.6 XIO'
NOTES^
I. INNER BAY IS DEFINED AS THAT PORTION OF THE BAY
WEST OF SECTION .
2. MIDDLE BAY IS DEFINED AS THAT PORTION OF THE BAY
BETWEEN SECTION AND SECTION AND SECTION
-------
substance (a means of determining pre-
sence of detergents) (UNLV/Clark County
Contract, 1974).
In the Las Vegas Valley excess lawn irri-
gation water percolating to the shallow
water table is probably the greatest
source of salinity in the entire ground-
water basin. The water passing the root
zone of the grass and ornamental plants
contains saline concentrations signifi-
cantly higher than the applied irrigation
water due to the processes of evapotrans-
piration which tends to concentrate salts
in the drainage waters. For example,
in 1973 over 33, 000 acre-feet of irri-
gation water was applied to lawns and
shrubs in the Valley. Of that amount, it
was estimated that almost 22,000 acre-
feet was percolated to the shallow ground-
water table. From the evapotranspiration
processes, the salt concentration of the
return flow would be estimated to be
abput 40% greater than applied water
salinity. In addition, significant quan-
tities of soluble fertilizers were probably
carried with the downward percolating
return flow. An even greater source of
salinity is the native salt which is pre-
sent in the alkali soils that cover much
of the Valley. Due to the low yearly
rainfall in the Basin, natural leaching
of these salts has not taken place in
recent geologic time. With the develop-
ment of subdivisions, and the subsequent
"over-irrigation" practices of the typical
homeowner, these saline soils are now
increasingly flushed out by the ensuing
return irrigation flows. The total im-
pact of agricultural and lawn watering
practices in the Valley cannot be quanti-
fied, but the cumulative effect of evapo-
transpiration, fertilizers and saline soils
must be significant. In addition to the
residential lawn watering practices in
the Valley, the irrigation of golf courses,
agricultural crops, park and school
lawns, and miscellaneous commercial
lawns contributes to the degradation
of the near-surface aquifer system. The
above table describes the volumes of
water that were used for irrigation in
1973, and the estimated excess irriga-
tion water that probably percolated past
the root zone in that year.
WATER RIGHTS
Surface Water Rights
White settlers began irrigation lands on
the upstream tributaries of the Colorado
River and the Las Vegas Valley area,
using surface water, during the 1850's.
The history of water development in this
region is largely one of deficient surface
water supplies, being supplemented by
the ground-water resources.
Some of the major documents concerning
the Colorado River are briefly summar-
ized below.
The Colorado River Compact, in 1922,
was set up to provide for the diversion
of waters from the Colorado River System.
It also established a preference for agri-
cultural and domestic uses over uses
for power generation. The water supply
of the Colorado River system is less than
that expected by the Commissioners who
68
-------
AVAILABLE
SUPPLY
-I.OOOACRE-FSET
CONTRACT
ALLOCATIONS
SOUTHERN NEVADA
WATER SYSTEM
PHASE
-133,300 ACRE - FEET CAPABILITY
LAB VEQAB VALLEY WATER DISTRICT
PJOPTH LAS VEQAB
YEAR
-------
negotiated the Compact.
The Boulder Canyon Project Act of 1928
authorized the construction of Hoover Dam
and Powerplant and the All-American
Canal. The Act also authorized the
States of Arizona, California and Nevada
to enter into an agreement whereby the
7. 5 million acre-feet of water that was
apportioned annually to the Lower Basin
States of the Colorado River Compact
would be as follows: to California, 4.4
million acre-feet; to Arizona, 2.8 million
acre-feet; and to Nevada, 0.3 million
acre-feet.
The Upper Colorado Basin Compact of
1948 apportioned the Upper Basin share
of the Colorado River waters among the
States within that Basin.
tary of the Interior to prepare long-
range water resource studies directed
toward the augmentation of the Colorado
River, to prepare criteria for the coor-
dinated long-range operation of the
Colorado River reservoirs, and to under-
take programs for water salvage and
ground-water recovery along and adjacent
to the main stream of the Colorado River.
Existing contracts for Nevada's allocation
of Colorado River water include both Las
Vegas Valley use and use below Hoover
Dam. Use of water in Nevada in the
Moapa Valley and along the Virgin River
is not charged against Nevada's allocation
of Colorado River water. Table 7 sum-
marizes water delivery contracts for the
Southern Nevada Water Project. Table 8
is a summary of the existing contracts
for Colorado River water.
The Mexican Treaty of 1944 allocated
to Mexico 1. 5 million acre-feet of Colo-
rado River system water annually, to be
increased in years of surplus to 1.7
million acre-feet, and also provided for
a proportionate reduction during extra-
ordinary drought.
The Colorado River Basin Project Act
of 1968 authorized the Central Arizona
Project, the Dixie Project in Utah, and
five projects in the Upper Basin. The
Central Arizona Project will provide the
conveyance and storage facilities to im-
port Arizona's remaining share of Colo-
rado River water into the Gila River
Basin. The Act also directs the Secre-
Existing contracts do not exceed the
300, 000 acre-foot allocation, but with
the addition of potential future contracts,
there is approximately 100,000 acre-feet
annually of excess demand from about
1990 on. Two possibilities exist for meet-
ing this demand for Colorado River water
that exceeds the present allocation. One
would be to obtain credit for return flows
to Lake Mead re suiting from the diversions,
and the other would be to divert Las Vegas
Wash flows to the Alfred Merritt Smith
Treatment Plant for recycling.
Ground Water Rights
Nevada has a specific ground-water statute.
70
-------
Water Delivery Contracts for the
Southern Nevada Water Project
Agency
Delivery
Contract
First Stage
(acre-feet/year)
Deliveryc
Contract
Option
(acre-feet/year)
Ultimate
Delivery
Potential
(acre-feet/year)
Nellis Air
Force Base
North Las Vegas
Las Vegas Valley
Water District
Henderson
Boulder City
4,000
20,000
99,200
7,000
2,000
132,200
0
20,000
100,800
33,000
13,000
166,800
4,000
40,000
u
200,000°
40,000
15,000
299,000
Estimated Losses 5,800
Diversion
Acre-feet Per
Year
5,200
138,000
172,000
11.000
310,000
a. Contract provision option, which is subject to construction of
additional stages, availability of water, and payment of charges.
b. Includes 15,407 acre-feet/year which, after June 1, 1990, is
expected to be delivered to the Las Vegas Valley Water District
through this system. Contract No. 14-06-300-2130 dated
September 22, 1969, with United States.
c. Contract between United States and Colorado River Commission
dated August 25, 1967, Contract No. 14-06-300-1974.
Source: Colorado River Commission of Nevada.
71
-------
Legislation in 1913 provided a law for the
conservation of underground waters, and
declared all sources of water supply within
the boundaries of the State, whether above
or beneath the surface of the ground, to
belong to the public. To appropriate
water, which is the property of the State,
an application must be made to the State
Engineer. If there is no interference with
existing water rights on the source, a
permit may be issued to develop the waters
to a beneficial use. A certificate will
be granted within a limited time for the
actual quantity of water placed to a bene-
ficial use which is then the limit and
extent of the water right. The Ground
Water Act of 1939 provided the first
specific legislation for the regulation
of underground waters.
subsidence and decreased water quality.
The mineral quality of ground water
ranges from excellent to unsuitable for
any purpose. Ground water in the allu-
vial deposits of the Basin and Range low-
lands, for example, contains from less
than 100 to more than 100, 000 milligrams
per liter of dissolved solids. In most of
these deposits, however, dissolved solids
concentrations are less than 1,000 milli-
grams per liter. Concentrations vary
not only with location, but also with depth.
As a result, the concentrations of dis-
solved solids for a given well will change
abruptly and so will the ionic makeup.
With the introduction of Southern Nevada
Water Project deliveries, ground-water
overdraft is being curtailed by the State
Engineer, and ground water pumpage
reduced to 50, 000 acre-feet per year.
Much of the present economic development
of the area has been made possible through
the use of ground-water reserves. Even
though these ground-water reserves are
still large, many problems attendant to
extraction and use may preclude the fur-
ther economical development within this
region of much of this resource. Con-
tinuing dependency on ground-water over-
draft to sustain or expand the region's
economy must be analyzed carefully.
The area of greatest demand in this
planning region is the Las Vegas Valley,
which has relied substantially on the
ground-water resource. Since the days
of flowing artesian wells in the 1940's,
depths-to-water for important wells have
increased markedly. In some areas
ground-water levels have declined as much
as 20 feet annually. In some cases, this
overdraft has been accompanied by ground
AIR QUALITY
The air quality of the region is good ex-
cept in the areas of urban development.
All urban areas have a high percentage
of particulate matter in the air due to
dust from a disturbed desert environ-
ment. In the desert a fine crust is
formed on the top layer of soil after
each rain. Breaking this crust allows
the fine, dry soil to be blown away. In
all areas of the region, construction and
dirt road driving combined with high
winds creates a dust problem.
Nitrogen dioxide, carbon monoxide, and
hydrocarbon counts are steadily increas-
ing in the Las Vegas area, causing grow-
ing concern, Air quality in the Las Vegas
72
-------
1973 EMISSIONS INVENTORY SUMMARY
FOR CLARK COUNTY, NEVADA
(Tons Per Year)
Source Total
(tons per year)
1.
2.
3.
4.
5.
6.
Emission Source
Mobile
Industrial Processes
Power Generation
Domestic, Industrial,
Commercial Space
Heating
Solid Waste
Disposal
Other Fugutive
Dust
Particulates SO 2
1,951
(2.63)
41,986
(56.7)
16,127
(21.8)
458
(.61)
19
(.02)
13,478
(18.2)
2,661
(6.72)
519
(1.31)
35,257
(89.14)
1,107
(2.8)
8
(.02)
-0-
CO
162, 442
(97.0)
3,001
(1.79)
1,810
(1.08)
169
(0.10)
32
(.02)
-0-
HC
42, 527
(81.43)
8,480
(16.24)
861
(1.65)
345
(.66)
14
(.02)
-0-
NOX
35,057
(51.92)
1,489
(2.2)
28,929
(42.84)
2.047
(3.03)
9
(. 01)
-0-
244,638
55,475
82, 984
4,126
82
3,478
TOTAL EMISSIONS
74,019 39,552 167,454 52,227 67,531 400,783
Note: Number in parenthesis is percent of total emissions
Source: Air Pollution Control Division of the District Board of Health
of Clark County
-------
metropolitan area is considered poor
relative to the standards adopted by EPA.
The topographic features of the Las Vegas
bowl aggravate atmospheric pollution prob-
lems. Atmospheric inversion conditions
prevail November through January; periods
of stagnation often last for several days.
The most complete measurement of air
pollutants in the Las Vegas Valley area
are taken at the Clark County District
Health Department measuring station.
Motor vehicles are the major contributors
to air pollution in Clark County, Nevada,
accounting for 97.0%, 81.43% and 51.97%
of the carbon monoxide (CO), hydrocar-
bons (HC), and nitrogen oxide (NO)
emissions, respectively. The other
industrial activities responsible for air
quality degradation in the County are
power generation and various process
operations. The power plants discharge
89. 14% of the sulfur dioxides and 21.8%
of the total particulates. In the 1973
emissions inventory summary for Clark
County shown in Table 9, mobile sources
are responsible for the annual discharge
of 162, 442 tons CO; 42, 527 tons HC;
35, 057 tons NO; 2, 661 tons SO2; and
1, 951 tons of particulates for a total of
244, 638 tons/year as compared to 82,984
tons/year for power plants and 55,475
tons/year for industrial processes.
This data identifies the importance of
controlling motor vehicle emissions as
a means for the attainment and mainte-
nance of clean air standards. In addition,
the evaluation of the potential air quality
impact associated with the proposed pro-
ject must consider not only the various
project elements, but the motor vehicle
activity associated with those elements.
This consideration is further emphasized
by the "complex source" amendments to
Nevada Air Quality Regulations.
Nevada has been among the earliest State
governments to adopt "complex sources"
amendments to their Air Quality Regula-
tions. These Air Quality Regulations,
as shown in Appendix D, define a complex
source as a facility which involves secon-
dary activities that may emit any air con-
taminant for which there is an ambient
air quality standard. Thus, shopping
centers, parking lots, residsntial or
institutional developments, and water,
sewer, power, and gas lines are exam-
ples of facilities which will involve in-
creased air pollutant emissions from
motor vehicles. In the assessment of the
impact of these emissions on the ambient
air quality, the need for background air
quality data becomes mandatory. Thus,
the final air quality is represented by the
sum of the emissions from a complex
source and the existing or background
concentrations on the various pollutants.
The Air Pollution Control Division of the
District Health Department of Clark
County has developed some background
data for oxidants photochemically pro-
duced from the reaction of nitrogen oxides
and hydrocarbons, nitrogen oxides and
particulates. These are shown in Fi-
gures 18 and 19 for each month of the
year 1973 as monitored in the vicinity of
downtown Las Vegas. The values of each
14
-------
High and Low Extremes
For Each Month
X
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I High Hourly Average
T
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Daily Average
250- •
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State of Nevada Ambient
Air Quality Standard*
T
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100- •
M
•Annual Arithmetic Mean
M
MONTH
-------
High and Low Extremes
For Each Month
I High Hourly Average
JL
I Daily Average
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1973 PHOTOCHEMICAL OXIDANT
CONCENTRATIONS - CLARK COUNTY
HEALTH
T
State of Nevada
I Ambient Air
\ Quality Standard*
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Monthly J
DEPARTMENT STATION
LAS VEGAS, NEVADA
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MONTH
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j
-------
-------
pollutant are plotted against a reference
value representing the State of Nevada
Ambient Air Quality Standards; 160 ug/m3
for the oxidants, 100 ug/m3 for nitrogen
oxides and 150 ug/m3 for particulates.
Both the photochemical oxidants and parti-
culates ambient air concentrations lie
above the standard values. Parallel data
for CO and HC are unavailable at the
present time.
Because of the major role played by motor
vehicles in the degradation of air quality
in Clark County, Nevada, the complex
source legislation constitutes a realistic
approach for the assessment of automotive
emission sources. However, there is a
requirement for additional background air
quality data for the implementation of the
complex source regulation. Aware of this
need, the U.S. Environmental Protection
Agency awarded a contract to TRW, Inc.
in mid-February 1974 to develop air
quality projections for Clark County.
This study involves the examination and
upgrading of the previous 1973 emission
inventory for both mobile and stationary
sources followed by the conversion of
these values to air quality concentrations
for CO and oxidants.
In order to assist in the implementation
of the complex source regulations, the
State of Nevada has contracted Aeroviron-
ment, Inc. to monitor ambient air quality
and develop data on wind patterns, vertical
temperature structure, and inversion inci-
dence in Nevada. This data will permit
the development of diffusion models to
facilitate the conversion of motor vehicle
emissions to ambient air concentration
for the major pollutants. This study will
also address itself to the meteorological
and topographical conditions peculiar to
the State of Nevada.
Due to the inconclusive state of present
air quality data development, it is diffi-
cult to assess the meaning of existing data
since this planning process is still under-
way. However, data available for 1971
may serve as some kind of historical
indicator.
The annual arithmetic mean of nitrogen
dioxide measured at the Health Depart-
ment in 1971 was 36 micrograms per
cubic meter (ug/m3). This compares
with the maximum annual arithmetic
mean allowed under the National Primary
Ambient Standard for nitrogen oxides
of 100 ug/m3.
The annual 1971 arithmetic mean of sus-
pended particulates measured at the Health
Deparment was 70 ug/m3, compared
with the National Primary Ambient Stan-
dard of 75 ug/m3. This mean value of
suspended particulates at the Health
Department tends to increase near more
congested metropolitan areas and tends
to decrease away from the central city
area.
The measurement of particulates at the
Health Department reached a maximum
of 240 ug/m3 for one 24-hour period in
1971, compared with the National Pri-
mary Ambient Standard of 260 ug/m3.
78
-------
AMBIENT AIR QUALITY STANDARDS
1. The following concentrations of air contaminants
shall not be exceeded at any single point in the
ambient air:
a. Sulfur oxides as sulfur dioxide:
Annual arithmetic moan 60 ug/M^ (0.02 ppm)
Maximum 24 hr. concentration 260 ug/M-^ (0.1 ppm)
Maximum 3 hr. concentration 1300 ug/M-* (0.5 ppm)
b. Suspended participate matter:
Annual geometric mean 60 ug/M'
Maximum 24 hr. concentration 150 ug/M^
c. Carbon monoxide:
Maximum 3 hr. concentration 10 mg/M-* (9.0 ppm)
Maximum 1 hr. concentration 40 nig/M-* (35.0 ppm)
d. Photochemical oxidant:
Maximum 1 hr. concentration 160 ug/M5 (0.08 ppm)
Non-methane hydrocarbons:
Maximum 1 hr. concentration 160 ug/M^ (0.24 ppm)
Nitrogen dioxide:
Annual arithmetic mean 100 ug/M^ (0.05 ppm)
means micrograms of air contaminant per cubic
meter of air.
rng/M-^ means milligrams of air contaminant per cubic
meter of air.
ppm means parts of air contaminant by volume per
million parts of air by volume.
3. The methods of measurement shall be those precribed
in Appendices A through F, inclusive, of § 410 of
Chapter IV, Title 42, Code of Federal Regulation,
published in the Federal Register on April 30, 1971. .
These may change from time to time.
4.
c.
f.
Adoption of these Ambient Air Quality Standards
shall not be considered in any manner to allow
significant deterioration of existing air quality
in any portion of Clark County.
table 10
-------
Photochemical oxidants at that time were
the most excessive form of air pollutants
in the Las Vegas area. The National
Primary Ambient Standard states that
photochemical oxidants should not exceed
160 ug/m3 for a one hour period more
than once during any one year. At the
Health Department station, the quantity
of photochemical oxidants exceeded the
Standard for 1, 304 hours during 1971,
and on one occasion reached a one-hour
maximum of 478 ug/m^. It would appear
the above average amount of sunshine in
the Las Vegas area is a factor in the
formation of photochemical oxidants.
Carbon monoxide was only measured
during a five-week period in November
and December of 1971. During this
period, the amount of carbon monoxide
measured at the Health Department ex-
ceeded the National Primary Ambient
Standard of 10 mg/m^ during an eight-
hour period more than twofold. This
exceedance of the Standard occurred
at two different times rather than once
as permitted by the Standard. One-hour
concentrations of carbon monoxide at
the Health Department in 1971 never ex-
ceeded the Standard for a one-hour
period during the test in November
and December.
At that time there was no equipment
in the Las Vegas area that measured
hydrocarbon, even though hydrocarbon
concentrations were believed to be high.
Sulphur dioxide in the area was consi-
derably well below the National Pri-
mary Ambient Standard and in some
cases it was below the point of mea-
surability.
A more complete breakdown of mea-
surement taken at the Clark County
District Health Department for photo-
chemical oxidants and nitrogen dioxides
during 1973 is included in Appendix D.
Air Quality Contributions From
The Proposed Allen Power Plant
The proposed Allen Power Plant will
contribute substantial amounts of sulfur
oxides, oxides of nitrogen, and parti -
culate matter into the atmosphere close
to Las Vegas. Foreseeably through at-
mospheric reactions, the formation of
sulfates and nitrates will increase the
possibility for the formation of ozones,
one of the prime ingredients in photo-
chemical smog. The volume of parti -
culate matter emitted will make ambient
standards attainment difficult and main-
tenance all but impossible for that pollu-
tant in the near future.
The Allen Power Plant will contribute
substantially to the degradation of air
quality in Clark County, Nevada, and
the Clark-Mojave-Yuma Interstate Air
Quality Control Region.
The combustion of 16, 000 tons per day
of low-sulfur coal (80% of the plant ca-
pacity) will result in 14.4 tons per day
(5, 260 tons per year) of particulate
matter to be emitted into the atmos-
phere. Atmospheric reaction will trans-
form approximately 10% of the power
plant's 150 tons per day (54, 800 tons
80
-------
per year) oxides of nitrogen emissions
and 10% of the plant's 34. 5 tons per day
(12, 600 tons per year) sulfur dioxide
emissions into nitrates and sulfates.
These nitrates and sulfates comprise
the particulate matter air quality read-
ing. A total of 2, 000 tons per year of
atmospheric pollutants will be measured
as particulate matter in Las Vegas, and
the Clark-Mojave -Yuma Interstate Air
Quality Control Region.
The State Air Quality Implementation
Plan records a 1970 estimate for Clark
County of man-made particulate emis-
sions to be 88,996 tons. By 1973 these
emissions of particulate matter de-
creased through enforcement of stringent
emission control regulations to 74, 019
tons per year. The State Plan estimated
the National Ambient Air Quality Standard
for particulate matter as:
150 ug/m3 -maximum 24-hour average
not to be exceeded more than one time
per year
60 ug/m3 annual geometric means
of 24-hour average.
With such a substantial increase in the
emissions of particulate and the forma-
tion of additional sulfates and nitrates
in the atmosphere, the Allen Power
Plant promises to cause serious degra-
dation in the quality of the air in and
around Las Vegas.
The recorded level of particulate matter
in 1970 was more than double the National
Ambient Air Quality Standard with the
maximum 24-hour concentration of 371
ug/m^ and an annual geometric mean of
137 ug/m3. The 1971 24-hour concen-
tration of particulates as presented in
the Environmental Assessment for the
Las Vegas Wash/Bay Pollution Abate-
ment Project showed that the maximum
24-hour concentration had increased
to approximately 480 ug/m3. No annual
geometric mean was provided but from
the statement of the annual arithmetic
mean (70 ug/m3) it can be assumed that
the annual geometric mean concentration
was substantially lower than in 1970.
VEGETATION
Regional Vegetation
The Lower Colorado Region has a wide
variation in vegetative cover types and
related categories. The forest types
extend from the small alpine areas on top
of Mount Baldy in the White Mountains,
the tip of Humphrey Peak in the San
Francisco Peaks, and the crest of
Charleston Mountain, Nevada; through
the coniferous forest zones of spruce-fir,
ponderosa pine, and the pinon-juniper and
oak woodlands and the chaparral types.
The rangeland type extends from the
forest type through the northern and
southern desert shrubs, the northern
and desert grasslands down through a
small area of true desert near the mouth
of the Colorado River on the boundary
between Mexico and Arizona. Scattered
81
-------
through the Region are areas of culti-
vated land, including irrigated pasture,
with the largest blocks in the Lower Gila
and the southern half of the Lower Main
Stem Subregions. More than 500, 000
acres of the Region are developed as
urban and industrial areas. More than
300, 000 acres of the Region are occupied
by water in the form of streams, lakes,
impoundments, and reservoirs. The
vegetative cover type is dependent upon
the precipitation, topography, soil, and
climate. In addition, each type is limited
to rather specific ranges in elevation.
Vegetal cover in the area of concern is
Southern Desert Shrub.
The perennial southern desert shrub types
occur in the southern and western portion
of the Region between 3, 000 and 4, 500
feet in elevation. The type is charac-
terized by cacti, woody plants, forbs
and grasses.
The ephemeral southern desert shrub
types occur along the western part of
the Region, usually at elevations below
3, 000 feet and less than 8 inches of
annual rainfall. The type is composed
largely of creosote bush with some
bursage growing in open stand with
little to no perennial ground cover.
Numerous annual forbs and annual
grasses may occur during favorable
periods of moisture.
Outside of the developed areas of the
regional environment, there is very little
vegetation. The area appears brownish-
grey, treeless, consisting of woody
shrubs rarely over one meter in height
with small annuals dispersed across the
desert floor. Grass is scarce in the
area, appearing quite often only after
rains along with green, succulent an-
nuals which remain for only a few
weeks. The ground is easily discerni-
ble due to little or no natural ground
litter and distance between vegetation.
KEY TO RELATIVE VEGETATION DENSITIES
Barren
Isolated
Sparse
Moderate
Dense
Ho growth.
Plant set alone in large area.
Distance between vegetative units greater
than the canopy size of these units.
Distance between vegetative units same
as the canopy size of those units.
Distance between plants or vegetative
units so small as to be difficult to
walk between.
82
-------
Three vegetation types and eight biotic
communities occur in the Las Vegas region.
These are as follows:
a. Desert Shrub vegetation type
(1) creosote bush community
b. Shrub and Woodland vegetation type
(1) desert riparian community
(2) saltbush community
(3) mesquite community
(4) salt cedar community
(5) pickleweed community
c. Marsh vegetation type
(1) cattail community
(2) bulrush community
(Haplopappus sp.),
juliflora).
mesquite (Prospis
The saltbush community is characteristic
of the playas between the creosote bush
and sagebrush deserts. Shrubs are small
to large, spacing is variable with arid to
seasonal surface moisture. Characteris-
tic plant species include shadscale (Atri-
plex confertifolia), hop sage (Grayia
spinosa), red molly (Kochia americana),
mesquite and other species of Atriplex.
Las Vegas Bay/Lake Mead has two types
of vegetation, terrestrial and aquatic.
Of these the mesquite, salt cedar, pickle-
weed, cattail and bulrush communities
are recognized as occurring only in the
Las Vegas Wash and therefore are des-
cribed in the appropriate section.
Predominant biotic communities of the
Las Vegas region, are the creosote bush,
desert riparian and saltbush communi *
ties. They are characteristic of the
common arid desert conditions. The
creosote bush community is most domi-
nant in the Las Vegas Valley area and
will be described in that section.
The desert riparian community is
common along the desert washes and
is characterized by such floral species
as cheese weed (Hymenclea salsola),
snake weeds (Gutierrizia sp.), bladder
sage (Salazoria mexicana), golden weeds
Terrestrial
Lake Mead lies within the Lower Sonoran
Life Zone. The dominant forms of vege-
tation are creosote and mesquite. Other
species present include saltbush, arrow
weed, greasewood, prickly pear cactus,
and barrel cactus. The hardy, alkali-
tolerant salt cedar, an introduced shrub,
has extensively colonized the wetland
immediately surrounding the Lake.
Aquatic
The relative abundance of the green and
blue-green algae, diatoms, dinoflagellates
and other phytoplankton of Las Vegas Bay
appears to fluctuate widely and with sur-
prising regularity. This phenomenon is
not yet completely understood. However,
it is believed that the variations are due
to changes in the distribution of nutrients
83
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City of Las Vegas
Wastewater
Treatment
Plant
Sanitation Dist.
Wastewater r—i
Treatment -»- 1
Plant
—Shrub-Tree-Marsh complex
DISTRIBUTION OF PLANT
COMMUNITIES ALONG LAS VEGAS WASH
AS DETERMINED BY
BRADLEY AND NILES (1973)
84
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contributed by the Las Vegas Wash out-
flow, within Las Vegas Bay. The regu-
larity of fluctuation may be due in part
to human factors, and in part, to natural
succession. In any case, a controlling
factor in the phytoplankton population
size at any one time, appears to be the
presence or lack of stratification within
the Bay waters.
During June large populations of colonial
green algae occurred throughout Las
Vegas Bay, but not near the Wash en-
trance to the Bay. At this time, a par-
ticular motile green algae (Carteria) had
high populations at the Wash entrance.
In July, the colonial green algae declined
and disappeared and were replaced by
Cyclotella diatoms. The location of
these organisms as the bloom began and
progressed indicates that "the origin of
this particular population maximum was
associated with the Wash". (Dr. J. Dea-
con, June and July 1972, Progress
Reports).
Area Vegetation
Vegetation in the valleys is typical of
that found in hot desert areas of the
Southwest. Generally it consists of
sparse growth of stunted desert shrubs
and grasses. There are no forests.
The dominant vegetation type in Las
Vegas Valley is the creosote bush com-
munity. This area has arid, low,
widely-spaced shrubs.
Las Vegas Wash consists of two areas -
85
a wide, dense marsh type environment
and a dense vegetation area. Data shows
that vegetative species diversity is great-
est in the desert plant communities rather
than in the marsh and stream riparian
habitats. This is basically due to the lack
of annual (herb) species within the marsh
vegetation type. Distribution of the plant
communities along the Las Vegas Wash
is shown on Figure 20. Generally speak-
ing, the classification of these biotic
communities is based on moisture gra-
dients as shown in Table 11. As stated
previously, the mesquite, salt cedar,
pickleweed, cattail and bulrush com-
munities are recognized as occurring
only in the Las Vegas Wash. The mes-
quite community is of the woodland vege-
tation type with roots reaching the water
table. The pickleweed community is
seasonal. It is found where there is
surface moisture with a salt crust. Both
the cattail and bulrush communities are
aquatic and have their roots in standing
water. The Wash is primarily made up
of areas of very dense cattails, reeds
and phragmites, often over six feet tall.
Along most portions of the Wash, a dense
growth of salt cedar borders the cattail
marsh. Beyond the salt cedar, habitat
ranges from salt-grass communities to
desert riparian. Located adjacent to
the Wash on the south side are the BMI
waste disposal ponds. These ponds sup-
port a moderate growth of salt cedar
on their borders and when filled with
water, provide an excellent habitat
for waterfowl. Vegetation in the Las
Vegas Wash as recorded by Bradley and
Niles (1972) appear in Appendix B.
The present extent of the marsh environ-
-------
VEGETATION TYPES AND BIOTIC COMMUNITIES
OF THE LAS VEGAS WASH
Vegetation types & biotic
Community
Desert shrub vegetation type
Creosote bush community
Shrub & woodland vegetation type
Saltbush community
Mesquite community
Salt cedar community
Pickleweed community
Marsh vegetation type
Cattail community
Bulrush community
Source; Bradley & Niles (1973)
Soil Salinity Soil Moisture
0.4%
0.5%
0.5%
0. 4 - 2%
1.8-6%
0.8%
0.5%
1.6%
2 - 5%
4.1%
8.5%
15 - 30%
standing water
standing water
-------
ment found in Las Vegas today is not
natural. Artesian springs fed Las Vegas
Wash until man began pumping water in
Las Vegas Valley. The artesian springs
stopped flowing and Las Vegas Wash be-
came an ephemeral stream; the upper
region exhibiting the same type of vegeta-
tion as now exists, but not as dense.
The lower region of the Wash was like
any other dry wash in the Las Vegas
area. Today, except during periods of
precipitation, the main flow of water
in the Wash is from sewage effluent and
ground water seepage, resulting in a
densely vegetated, vividly green marsh
in the middle of a very dry, sparsely
vegetated desert.
Site Vegetation
A list of basic biota of the selected site
environments, excluding the valley sites
is given in Appendix B.
Ground Water Recharge Well Field and
Pilot Desalination Plant
This site is moderately vegetated, dis-
playing the creosote bush and the desert
riparian biotic communities. The creo-
sote bush community occurs in isolated
patches on the flat mesas. The desert
riparian community type is dominant.
Because of the rocky soil and washes,
this site appears as a somewhat barren
and desolate area. Vegetation observed
in the area includes creosote bush, mormon
tea, ratney, niggerheads, challa caeltis,
prickly pear cactus and mojave yucca of
the Creosote Bush Community. Also
observed was the desert wash willow,
snake weed, and indigo bush of the Desert
Riparian Community. At the pilot desali-
nation plant, the area is sparsely vege-
tated with remnants of desert riparian
flora, particularly adjacent to the ephe-
meral Wash.
Waste Water Collection System, Treat-
ment Plant, Deep Disposal Well Field
Areas, and Sludge Disposal Site
The route of the collection system for
Alternatives 1, 4, 6, 7 and 8 is densely
vegetated with salt cedar along most of
its distance. For Alternatives 2, 3 and
5 the route is scarred, having a sparse^
growth of creosote and salt cedar cros-
sing through scattered marsh type vege-
tation. Vegetative species common at
the waste-water collection system for
Alternative 10, include salt cedar, bas-
sica, bermuda grass, and other grass
species.
The site for the waste-water regulation
reservoir and treatment facilities for
Alternatives 1,4, 6, 7 and 8, located
southeast of the Clark County Sanitation
District plant has sparse vegetation of
creosote with dense areas of salt cedar
and a small area of marsh vegetation.
For Alternatives 2, 3 and 5, the site is
sparsely vegetated. Portions of the
eastern boundary of the advanced waste-
water treatment plant site for Alterna-
tive 10, are vegetated with dense areas
of salt cedar and some marsh vegetation
within the Las Vegas Wash itself. A
preponderance of the site is irrigated
pasturage of bermuda grass.
87
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The area of the sludge disposal site is
sparsely vegetated, displaying the creo-
sote bush community. The vegetated
areas are primarily restricted to wash
areas while the more exposed areas are
generally barren. Because of the rocky
soil and washes, this site appears as a
somewhat barren and desolate area.
Las Vegas Lands to be Irrigated
Much of the land to be irrigated or used
for pipeline routing, has been disturbed
considerably by man1 s activities. As a
result, the areas support few floral spe-
cies characteristic of the more natural
areas. Vegetation found at this site
includes creosote bush, cat's claw, big
galleta grass and shadscale.
Dry Lake Valley
The dominant biotic community of Dry
Lake Valley is the creosote bush com-
munity. Yucca and cacti are found on
the higher alluvial slopes. The lake
bottom is barren except for fingers of
creosote, burro bush or mixed stands
reaching toward its center. Plant spe-
cies observed at this site during field
reconnaissance are creosote bush, burro
bush, mormon tea, mojave yucca, cholla
cactus, ratney, prickly pear cactus and
barrel cactus of the Creosote Bush
Community. Also found were snake
weed, cat's claw, desert holly, and salt
cedar of the Desert Riparian Community.
Eldorado Valley
Vegetation varies greatly in Eldorado
Valley, ranging from barren to dense.
There is a wide strip running east to
west in the middle of the Valley with
little or no vegetation on it. To the
west of Highway 95, this barren patch
is a dry lake bed, to the east of the
highway it is a very loose, rocky
drainage area, southward is a green
patch of dense growth consisting of salt
cedar and creosote bush caused by the
drainage of effluent from the Boulder
City sewage treatment plant. Looking
north and south, vegetation ranges from
sparse to dense. The southern end of the
Valley next to the dry lake, is sparsely
vegetated with creosote bush and small
annuals. The northern end of the Valley
adjacent to the dry lake, is densely
vegetated with creosote bush, burro
bush, big galleta grass and various an-
nuals. Higher up, towards the moun-
tains, in all directions, there is moderate
vegetation, creosote bush being the domi-
nant species. Plant species found at
this site include, creosote bush, burro
bush, russian thistle, pigweed, beaver-
tail cactus, and cholla cactus of the Creo-
sote Bush Community. Species of the
Desert Riparian Community include desert
marigold, big galleta grass, and salt cedar.
Species of the Salt Bush Community in-
clude shadscale and mesquite.
Jean Lake
Vegetation at Jean Lake varies from mode-
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rate to barren. The northern end and peri-
pheries of the study area have moderate
vegetation, creosote bush being the domi-
nant species with burro bush, ratney and
various annuals. Much of the study area,
from the dry lake southward, except for
the peripheries, is overgrazed. This area
is sandy, the only vegetation being big
galleta grass, grazed to the ground, leav-
ing vegetation clumps holding the earth
in place, or upright naked woody plants and
creosote bush. Flora observed at this site
is creosote bush, burro bush, ratney,
mojave yucca, cholla cactus, barrel
cactus, and beavertail cactus of the Creo-
sote Bush Community. Representative of
the Desert Riparian Community, is big
galleta grass, desert marigold, wild
tobacco, and desert mallow.
Hidden Valley
The major portion of Hidden Valley is al-
most barren. Only the outermost peri-
pheries of the alluvial slopes on the east
and west sides exhibit vegetation, with
greater portions of the northern and
southern ends having moderate vegetation.
The north, east and southern alluvial
slopes are dominated by creosote bush
with ratney, burro bush and various an-
nuals. Areas of the northern portion of
the Valley are gravel, almost barren
drainage areas. Here there are isolated
creosote bushes, with many small annuals
growing in washes. The barren, appar-
ently overgrazed area is sandy, with big
galleta grass clumps holding the soil in
place, giving the area the appearance of
a stormy sea. Plant species observed
at this site are, creosote bush, burro
bush, russian thistle, mojave yucca,
cholla cactus, ratney, and mormon tea
of the Creosote Bush Community. Of
the Desert Riparian Community, vege-
tative types were big galleta grass, green-
bottle bush, desert marigold, snake weed,
four-wing salt bush, and chinca weed.
WILDLIFE AND FISH
Regional Wildlife
Wildlife species in the Lower Colorado
Region are as many and varied as the
climate, terrain and vegetative types.
More than 750 species and subspecies of
birds and animals occur in the Region.
Over 40 of these species of wildlife pro-
vide hunting ranging from highly-prized
big-game hunting to sport hunting of non-
game species. Many other species, mos-
tly small mammals and birds, provide en-
joyment for the non-hunting outdoorsman
for nature study and photography. For
the purpose of this study, the wild game
species have been classified as big game,
small game, and waterfowl.
Big-game species in the Region are dist-
ributed throughout approximately 72
million acres of widely diverse habitat
types. Deer are the most abundant and
widespread of the big-game species, and
include the desert mule deer and the
white-tailed deer. Approximately 69.5
million acres within the Region are occu-
pied by the two species of deer. The
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pronghorn antelope occupy nearly 10 mil-
lion acres of the rolling grassland, occur-
ring in Arizona, and in similar areas of
Nevada, New Mexico, and Utah. Desert
bighorn sheep occur in several of the low
desert mountain ranges in southern Ne-
vada. Bighorns travel in small bands
through this arid country and, although its
numbers are low, it is one of the most
prized big-game trophies of the Region.
The javelina, or collared peccary, is
found at a low elevation. Javelina range
from the lower pinyon-juniper into the
southern desert shrub and chapparral
areas. Although population densities are
usually relatively low, the javelina range
is about 36 million acres.
Small-game species vary widely in the
extent of their range, some extending
nearly throughout the Region while others
are quite localized in distribution. Ex-
amples of species with a regionwide dis-
tribution are the mourning dove, cotton-
tail rabbit, the white-winged dove, and
the bandtailed pigeon. Limited in dis-
tribution are the blue grouse and sage
grouse. The Gambel's quail occurs pri-
marily in the desert and lower mountain
elevations of the Region. Several species
of fur animals including beaver, musk-
rat, grey fox, and kit fox occur in the
Region. While some species, such as the
kit fox are relatively limited, primarily
to the desert areas of the Lower Main
Stem and Gila Subregions, other species,
including the beaver, are widely distri-
buted throughout the Region. The fur am-
mals normally do not reach prime fur
condition which is attained in the cooler
climates, and the interest in trapping
for furs solely for profit is very low.
Fur animal species, such as foxes, are
also considered varmints, and as such,
are relatively heavily hunted. A small
number of furs are collected by varmint
hunters as a secondary benefit from hun-
ting. Several species of predatory ani-
mals and non-game animals, as well as
the previously mentioned fur animals,
are hunted in this Region. Most of these
species are well distributed throughout
the three subregions and include coyotes,
bobcats, mountain lions, jackrabbits, pra-
irie dogs, various ground squirrels, and
ravens.
Waterfowl are present in greatest concen-
trations in the Region during fall and win-
ter migration periods. A number of water-
fowl winter in the desert wetlands of the
Lower Main Stem. Suitable habitat for
waterfowl consists of 42, 000 acres of wet-
lands and marsh associated with perma-
nent streams and man-made lakes.
The distribution of some types of wildlife
in relation to human populations has a
great influence on their use. Certain big-
game species are not greatly affected by
these factors, since hunters will travel
great distances for such an attraction. A
large share of the demands from the Las
Vegas^area is satisfied outside the Region
in California and parts of Nevada. De-
mands on one species, therefore, do not
reflect the total demands on all species of
the Region. The rugged terrain of the Re-
gion, while creating a natural refuge for
wildlife in many areas, is a limiting factor
in the hunting of game. A lack of access
limits utilization of a sizable portion of
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the total wildlife resource. Although lack
of easy access to rough country is more
typical of remote areas, it is not limited
to these areas.
Designated wildlife developments and
facilities managed intensively for wild-
life production, include 49 multiple-and -
primary-use management areas, 568 ha-
bitat improvement facilities and access
roads, comprising a total of over 4 mil-
lion acres. Nine of the wildlife manage-
ment areas totaling over 3 million acres,
are administered by the Federal Govern-
ment; 32, of approximately 72, 000 acres,
are administered by State governments;
and 8, totaling over 930,000 acres, are
administered jointly by State and Federal
interests.
Nineteen of the wildlife areas in the Re-
gion, are developed primarily for big-
game populations, seven areas are deve-
loped for small game, seventeen set aside
for the protection of waterfowl, and three
for wildlife in general. In addition, one
recreation area and one public shooting
range are administered by fish and wild-
life interests and, are considered manage-
ment areas. Areas at higher elevations
are managed for the production of mule
deer, elk, antelope, turkey, and other
wildlife utilizing the area.
The Regional Aquatic Environment
There are about 85 species of fish in the
Lower Colorado River Region. Approx-
imately 25 species provide sport fishing.
The others are of value as forage fishes,
as pollution indicators, for scientific in-
vestigations, and as a source for a possible
commercial fishery. Some fifty-six spe-
cies of fish have been introduced into the
Region. The notable introductions of game
fish include all the common warmwater
sport and commercial fishes and all trout,
except the endangered Gila and Apache
trouts. Other game fishes introduced are
the coldwater species of walleye, gray-
ling, and northern pike. The introduced
warmwater species include striped bass,
white bass, channel catfish, flathead cat-
fish, yellow perch, and tilapia. The
threadfin shad has been introduced into
reservoirs below 4, 500 feet elevation
as forage for game fish. Fishes introduced
into the lakes on the Colorado River include
kokanee and silver salmon in Lake Mo-
have and Lake Mead. These fishes are
expected to add to the variety of fish
species available to the fisherman in the
Lower Colorado Region. Native species
have not provided any important sport or
commercial fishing in the Region for many
decades. In the cold waters impounded on
the Colorado River and the cool reaches of
the river below the dams, stocked rainbow
trout provide year-round fishing. On Lake
Mead, they provide a. supplemental fish-
ery. For the most part, introduced spiny-
rayed warmwater fishes predominate in
the waters of the Lower Colorado Region.
Largemouth bass is one of the major
game fishes in the Region and is found
in most lakes in the drainages of the Co-
lorado. Sunfishes are abundant in many
of the warmwater lakes and streams; blue-
gill and green sunfish are widespread
throughout the Region. The warmouth
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and redear sunfish are found in the lakes
of the Lower Colorado River. Crappie
are most common in the larger reservoirs
throughout the Region. Some crappies are
in smaller lakes up to 7, 000 feet eleva-
tion. Striped bass are found in the Colo-
rado River from near Blythe, California,
north to Lake Mojave and just recently
planted in Lake Mead. Catfishes are
found throughout the Region. Channel cat-
fish are the most prized catfish and are
found in most of the large reservoirs and
the Colorado River. Irrigation canals and
many stock ponds throughout the Region,
notably those on the Indian reservations,
have been stocked with channel catfish.
Black bullhead are found in small muddy
streams, lakes, and canals at lower ele-
vations. Yellow bullhead are found in
some of the small, relatively clear,
rocky streams.
The Region contains a variety of introdu-
ced fishes of potential commercial value.
Populations of food-fishes from wild re-
sources such as carp, buffalo-fishes, and
various suckers are found in the larger
reservoirs. Important species of bait
fishes such as the redshiner, fathead min-
now, speckled dace, redside shiner, and
threadfin shad are found regionwide in
most streams and lakes.
Fishing waters in the Lower Colorado Re-
gion include streams and man-made im-
poundments. There are no natural lakes
of importance to fishing. The fishery is
classified into two major categories: the
coldwater trout fishery of headwaters and
impoundments generally above 5, 500 feet
elevation; and the warmwater "spiny-
rayed" fishery in the streams and im-
poundments of elevations below 6,000 feet
elevation. The waters of the Colorado
River and other streams in the Region that
are stocked and provide trout fishing only
during the cooler months of the year are
classed as warmwater fisheries. There
are approximately 2,500 miles of stream
habitat for fishes in the Region comprising
approximately 10,200 surface acres of
which about 2, 000 acres and 8, 200 acres
are cold-and warmwater, respectively.
Impoundments provide nearly 241, 000 sur-
face acres of fishing habitat of which 7,000
acres are coldwater and 234, 000 acres are
warmwater.
Over 52% of the total fishing in the Region
occurs in the Lower Main Stem Subregion.
About 30% of the Region's coldwater fish-
ing occurs in the reservoirs and the cool
tailwaters found in the Subregion. About
60% of the Region's warmwater fishing is
realized in this Subregion, mainly in the
Colorado River and Lakes Mead, Mojave
and Havasu. Sixty-seven percent of the
fishing in the Region is in impoundments.
Impoundments are generally easier to fish,
provide more open water, and are more
accessible than most streams. Warm-
water impoundments, being more numerous
and located nearer to population centers,
support 49% of the total fishing as com-
pared to 18% from coldwater impound-
ments. Streams accounted for the re-
maining 33% of the total fishing. Again,
easier access accounts for warmwater
streams providing 23% of the total fish-
ing as compared to only 10% from cold-
water streams. Although the overall
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supply of sport fishing in the Region
presently appears adequate, many factors
tend to discourage or limit realization of
the available capacity. Poor distribution
of the supply relative to demand, is the
most important factor limiting full use
of the capacity. Sheer magnitude of the
demands generated by the population cen-
ters causes severe localized demand -
supply problems. Demand varies directly
with human population, and good quality
fishing opportunities vary inversely with
the population. A large share of Las
Vegas area demand is satisfied in south-
ern Utah and parts of California and Ne-
vada outside the Lower Colorado Region.
Fishery installations existing in the Region
consist of approximately 97 fishing lakes
and 8 fish hatcheries. The fishing lakes
provide more than 6,000 acres of water
for fishing. These lakes are constructed
and managed primarily for fishing and use
of the water surface is restricted. Nine-
teen of the lakes, totaling more than
1, 000 acres, are administered by State
fish and game agencies. FoUr lakes, pro-
viding about 900 acres, are administered
jointly by State-Federal agencies. Five
State hatcheries and three Federal hatche-
ries produce approximately seven million
fish, most of which are trout. Therefore,
over 90% of the trout caught in the Region
are stocked fish. The Region's production
is about 80% of the total fish stocked. The
remaining fish stocked are imported from
outside the Region.
Area Wildlife and Fish
Due to lack of data, excluding Las Vegas
Wash and Las Vegas Bay, fauna, like the
flora, is described according to biotic
communities. There are 10 species of
amphibians, 35 species of reptiles, 64
species of mammals and over 364 species
of birds expected to be found in the re-
gional area. Eleven of these species of
fauna are rare, endangered or of uncer-
tain status. Two hundred fifty-one of the
bird species are found in Las Vegas Wash.
Due to the geography of the area and it
being in the Lower Sonoran Life Zone, the
regional environment displays a wide di-
versity of species and many subspecies
unique to the area. Biologically this en-
vironment is very rich. A variety of
wildlife, including coyote, badger, kan-
garoo rats, cottontails, reptiles and bats,
is native to the area.
Las Vegas Valley is predominantly Creo-
sote Bush Community. Mammals charac-
teristic of this Community are the desert
jackrabbit (Lepus californicus), desert
cottontail (Sylvilagus audubonii), white-
tailed antelope ground squirrel (Citellus
leucurus), several species of bats, and
the Meriam's and desert kangaroo rats
(Dipodomys merriami and E>. deserti).
Common reptiles include the side-blotched
lizard (Uta stansburiana), western whip -
tail (Cnemidophorus tigris), zebratailed
lizard (Callisaura draconoides), and the
desert iguana (Byisaurus dorsalis) to
name a few. Thirty-three species of birds
occur in this community, among them, the
cactus wren, horned-lark, Gambel's quail,
common raven and Leconte's thrasher.
Las Vegas Wash has a variety of wildlife.
Diversity of vegetative species is greatest
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in the desert plant communities rather than
in the marsh and stream riparian habitats.
Conversely, the avifauna (birds) are found
to be more diverse and abundant in the
riparian communities as compared to the
adjoining desert communities. This is due
in part, to the availability of open water for
waterfowl and shorebird species which con-
stitute approximately 40% of all bird spe-
cies in the shrub-woodland-marsh vege-
tation type. There are 251 species of birds
found in the Las Vegas Wash, many of
which would not otherwise be found in the
area. Other fauna determined to occur in
the Las Vegas Wash include 6 amphibians,
29 reptiles (1 tortoise, 13 lizards and 15
snakes), 39 mammals (1 shrew, 10 bats,
16 rodents, 2 rabbits, 9 carnivores and 1
ungulate (bighorn sheep). Many of the spe-
cies are observed to occupy the ecotone
between the xeric desert habitat and the
hydric conditions of the marsh. Except for
birds and the few species of mammals and
reptiles, wildlife found in the Wash is
essentially the same as that of the surroun-
ding desert environment. Birds and spe-
cies unique to the Wash, such as beaver,
are listed in Appendix B. The Wash also
supports two introduced species of fish,
mosquito fish (Gambusia affinis), and gold-
fish.
The species composition of Las Vegas Bay
and Lake Mead fish population is contin-
ually changing as new stocking programs
and experiments are initiated. The var-
ious game fish comprised the following
percentages of the total 1971 catch: Large-
mouth Bass - 40%, Channel Catfish - 24%,
Black Crappie - 11%, Rainbow Trout
14%. The Largemouth Bass is still con-
sidered to be the most important game
fish although it h.as comprised a steadily
diminishing proportion of the total catch.
The Rainbow Trout has recently increased
in importance due to heavy stocking. The
new stocking programs have been initiated
in an effort to improve the steadily dec-
reasing rate of angling success which has
accomplished increased angling pressure
on the lake. (See Table 8 - "Species of
Fish Presently Found in Las Vegas Bay").
A new fish hatchery has recently been lo-
cated on the Nevada side of Lake Mead on
National Park Service land. It is admini-
stered by the Nevada Department of Fish
and Game and is known as the Lake Mead
Fish Hatchery. It has been in operation
for the past year and is raising both spe-
cies and hybrids of trout, (rainbow and
cutthroat) and salmon (coho and chinook).
Plans are to stock Las Vegas Bay/Lake
Mead with 200, 000 pounds of catchable
fish a year.
Site Fish and Wildlife
A list of Basic Biota of the site environ-
ments, excluding the valley sites, is given
in Appendix B.
RARE AND ENDANGERED SPECIES
Rare species are those whose numbers are
few throughout their range of habitat. So
long as conditions remain stable and favor-
able, such species may continue to survive
in limited numbers. Endangered species
are those so few in numbers or so threa-
-------
*Largemouth black bass
*Channel catfish
*Black crappie
Carp
*Bluegill sunfish
*Rainbow trout
Green sunfish
+Humpback sucker
Western golden shiner
German brown trout
Black bullhead
+Bonytail chub
Mosquito fish
+Colorado River Squaw fish
*Cutthroat trout
*Silyer salmon
*Striped bass
Threadfin shad
Walleye
* Important game fish
+Nevada protected list
(Micropterus salmoides) Abundant
(Ictalurus punctatus) Abundant
(Pomoxis nigromaculatus) Abundant
(Cyprimus carpio) Abundant
(Lepomis macrochirus) Common
(Salmo gairdneri) Common
(Lepomis cyanellus) Common
(Xyrauchen texanus) Common
(Notemigonus crypolencas) Common
(Salmo trutto) Rare
(Ictalurus melas) Rare
(Gila robusta) Rare
(Gambrusia affinis) Rare
(Ptychocheilus lucius) Rare
(Salmo clarkii) Common
(Oncorhynchus kisutheh) Common
(Morone saxatilis) Common
(Dorosoma petenense) Abundant
(Stizostedion vitreum) Rare
-------
THREATENED SPECIES LIST
Common Name
Vegas valley
leopard frog
Gila monster
Spotted bat
Prairie falcon
California brown
pelican
Wood ibis
American peregrine
falcon
Ferruginous hawk
Osprey
Mountain plover
Long-billed curlew
Prairie pigeon
hawk
Bald eagle
Scientific Name
Rana fisheri
Heloderma suspectum
Euderma maculata
Falco mexicanus
Pelecanus
occidentalis
Mycteria americana
Falco peregrinus
Buteo lagopus
Pandion haliaetus
Eupoda montana
Numenius americanus
Falco columbianus
richardsonii
Haliaeetus
leucocephalus
F.R.
E
B.S.F.&W.
T
U
T
T
U
U
T
U
U
U
U
U
1 F.R. Federal Register, vol. 38, no. 106. June 4, 1973.
2 B.S.F.&.W. Bureau of Sport Fisheries and Wildlife. Threatened
Wildlife of the United States, 1973
E Endangered
T Threatened
U Status uncertain
-------
tened by present circumstances as to be in
danger of extinction.
Regional Rare and Endangered Species
There is no known rare or endangered
plant species list compiled for the Las
Vegas region. However, future research
in the region may identify some species as
needing this classification.
The U.S. Bureau of Sport Fisheries and
Wildlife has updated the Federal publi-
cation of rare and endangered wildlife.
The 1973 publication is entitled "Threa-
tened Wildlife of the United States" and
no longer categorizes wildlife as rare
or endangered. As a result of changes
in the status of several wildlife species
inhabiting the Las Vegas region, 13 spe-
cies are now considered threatened or of
undetermined status.
In its previous publication, Number 34,
"Rare and Endangered Fish and Wildlife
of the United States" (Red Book), the
Bureau lists the Merriam elk as the only
species to become extinct in the Lower
Colorado Region. Classified in the "Red
Book" as "rare" forms of mammals found
in the Region are the spotted bat and Kaibab
squirrel. Rare fishes include the Virgin
River spinedace and wound fin. The Vegas
Valley leopard frog is listed as rare in the
amphibian class.
The "Red Book" lists eight "endangered"
species in the' Lower Main Stem Subregion.
The one endangered mammal is the Sonoran
pronghorn. Three birds are listed; the
American peregrine falcon, the Yuma clap-
per rail, and the southern bald eagle.
There are four fishes classified as endan-
gered; the Arizona (Apache) trout, the
humpback chub, the Moapa dace, and the
Colorado River squawfish.
HISTORICAL BACKGROUND
Before the first European came to Las
Vegas Wash in the winter of 1829-30,
only the nomadic Southern Pahutes
(Root Diggers or Pah Utah Indians) dis-
turbed the Wash. These nomadic Indians
from the nearby mountains and the Colo-
rado River passed through on occasion and
there were apparently no permanent settle-
ments in the region. The chief attractions
were the cool waters of Las Vegas Spring
and the long stringed beans of the native
Mesquite trees that grew in Las Vegas
Valley at the upper end of the Wash.
The apparent first intrusion by Europeans
into Las Vegas Wash was by a caravan
entering the Wash on January 7, 1830.
Rivera, a scout who rode alone and ahead
of the caravan, very likely entered Las
Vegas Wash about a week before when he
was looking for a possible short cut for
the party.
John Charles Fremont, the noted explorer
and pathfinder, came to Las Vegas Wash
on May 3, 1844. He commented on the
springs of Las Vegas, situated in the mid-
dle of Las Vegas Valley, "With a tempera-
97
-------
O F C A L I F O N T A
Siw/w Xn-nda 0~
milfs, xnnie />i>irif>njt of its surface, ufr arid at d.
sandy, titid destitute of water and. grass, w)iil>
tftsr t/uartm. rivrrs and UiJcts are kntwi tt> ai
\ .V JL N J)
SftT-TC
A M A C H V
Beniwrtin
i%i
-f
yw • *->^»A,^i0upjr,«w,« . _ •," xfflk '1
''i^Mf' Jm1
THE SPANISH TRAIL
-------
ture of about 72 the springs gushed forth
suddenly with a quick current producing tv
clear springs four or five feet deep. "
Fremont, in his report to Congress, also
commented on the vegetation at the upper
end of Las Vegas Wash, "There were mes-
quite trees with their yellow flowers and
a colored assortment of spring wildflowers
in bloom. " He also recorded a number of
other species of shrub in his report.
The U.S. acquired all of its present south-
western lands (excepting southern Ari-
zona) in the war with Mexico through
provisions set forth in the Treaty of
Guadelupe Hidalgo in 1848.
The Old Spanish Trail had its eastern ter-
minus at Santa Fe, New Mexico and its
western terminus was Los Angeles. It
functioned from 1830 to 1848. The Salt
Lake - Los Angeles Trail, which from
southern Utah to Los Angeles essentially
was the same as the retired Spanish Trail
served as an artery to the California Gold-
fields in 1849. Mormons travelled this
trail from Salt Lake City to their colony
in San Bernardino beginning in 1851. Cali-
fornia-bound gold seekers used the same
trail. All partook of the cool waters of
the Vegas and crossed the upper end of
Las Vegas Wash.
In June 1855, the Mormons decided to es-
tablish a mission and fort, the first white
settlement in the very heart of Las Vegas
Valley on the route of the Salt Lake Trail.
By that date this spot had become well
known as a good place to rest and recu-
perate on the trek between centers of ci-
vilization.
To the east of the fort were farm and gar-
den plots. Beyond them, was a vast mes-
quite forest extending from the fort
down Las Vegas Wash to the base of Sun-
rise (Frenchman) Mountain. The forest
passed by that mountain and spread out to-
ward the Colorado River. On either side
of this forest of mesquite was desert - -
mostly low forms of plant life and sage-
brush. There were no trees in those areas
except occasionally mesquite. The mes-
quite trees closer to the fort were cut and
used for fencing and for fuel. Mesquite
wood burns readily, even when it is green.
It creates a very hot fire, and as a fuel,
some say it is equal to hickory. It is also
an exceptional building material. The
trees blossom late in spring; the fruit ap-
pears in long slender beans from which
Mexicans and Indians made a cool beve-
rage. The beans ripen in early fall; the
mature fruit, which falls to the ground,
affords sustenance to small birds and
wild animals. The highly nutritious pods
afforded food for the Indians, who crushed
and pressed the beans into delectable
cakes.
The Mormons abandoned their Las Vegas
mission in 1857 after only two years of
effort. They had cultivated nearly 150
acres and gathered some fair crops of
vegetables, grains, and even some cot-
ton and tobacco. Clearing away tracts
of land proved to be an immense job
99
-------
because of the presence of saleratus --
alkali in the soil. This saleratus, or
sodium bicarbonate (baking soda), ap-
pears on the top of the ground in many
areas of Las Vegas Wash after a rain-
storm. It bubbles up like fizz water,
and leaves a coating on top of the ground
which is known as alkali. After the Mor-
mons left in 1857 (some stayed until
1858), the trail between Salt Lake and
Los Angeles was busier than ever. Mor-
mon missionaries, emigrants, mail
riders, freighters and others all passed
through the upper end of Las Vegas Wash
and stopped at the welcome springs of Las
Vegas. This was an all-year travel route,
as opposed to the one through northern Ne-
vada and northern California, which was
snowbound in winter.
During 1859-1865, several settlers took
up land in Las Vegas Valley for ranching
and farming. They sold their surplus
to travelers on the Salt Lake Trail and to
miners who began working at the nearby
Potosi and Eldorado Canyon mining dis-
tricts. Early in 1865, Octavius Gass
and two partners began to rebuild the old
Mormon farms at the upper end of Las
Vegas Wash but, within a few years,
Gass bought them out, and by owning
all of the local water, he became a vir-
tual king of the valley. Early in 1868,
as owner of the ranch, Octavius Gass
tried to sell his holdings. In an ad-
vertisement in the Rio Virgen Times
in Saint George, he described the soil
in the upper Las Vegas Wash as a black
rich loam that would produce vegetables
or grains in abundance. In 1969-1970,
Stanley H. Paher conducted oral inter-
views with the son of Octavius Gass, who
recalled living at Las Vegas Ranch. He
said that the dark soil was indeed good,
especially for the growing of pink Mexi-
can beans, as well as truck produce.
This son, Fenton Gass, also noted the
lush green belt that extended in the
direction of Henderson, and further de-
scribed Las Vegas Wash as a wet area
with moisture.
Nevada's State Mineralogist visited Las
Vegas Valley in 1871, and filed this re-
port:
"The most productive and valuable traqt
of land in Las Vegas Valley is near its
center, where is situated the Las Vegas
Ranch. . . There are several hundred acres
of very rich land here, though only about
150 acres are tilled. This portion of it
is well fenced, and improved with shade
and fruit trees. The orange, lemon,
peach, apple, pear, apricot, fig and
pomegranate are some of the varieties
of fruit trees. Grapes also grow. . .
the mesquite bushes, of which there are
many in the valley, furnish a very nutri-
tious bean, which all animals feed upon
as soon as the grasses die in the fall.
Stock keeps as fat upon this feed during
the winter months, as though fed upon
the best of hay and grain. "
Gass sold out Las Vegas Ranch to Archi-
bald Stewart in 1881; in 1902 the widowed
Mrs. Stewart sold most of the ranch
and water rights to the San Pedro Los
Angeles and Salt Lake Railroad, which
built a railroad across the Valley and
101
-------
v •
; /
»•..
LAS VEGAS VALLEY - 1871
-------
upper end of Las Vegas Wash during the
winter of 1904-05. Connected with the
sale, a local surveyor named J. T. Me
Williams, surveyed the Ranch in 1904.
This was in preparation for the surveying
of Las Vegas Townsite, which was auc-
tioned on May 15, 1905. In 1905, when
designated as a major division point of
the Union Pacific Railroad, the City of
Las Vegas was founded.
Las Vegas attained a population of about
800 by 1910. By that date homesteads
of ranches and small farms flourished
throughout the Valley, including in Las
Vegas Wash. Development was naturally
slow because it took several months to
uproot mesquite and sagebrush and pre-
pare the ground for cultivation. Explo-
ration began for underground sources of
water once the Las Vegas Springs could
not meet the demands of homesteaders.
Several hundred artesian wells were sunk
between 1907 and 1914. (Artesian wells
flow spontaneously from the surface and
require no pumping). Probably the larg-
est ranch in Las Vegas Wash was the
Winterwood Ranch. It acquired its name
because people in Las Vegas would go
there to cut mesquite trees for their
winter wood for cooking and heating pur-
poses. Over the years until the present,
hundreds of people settled in the upper
end of Las Vegas Wash. The Winterwood
Ranch became a huge subdivision.
103
Success in growing things in Las Vegas
Wash depended on a knowledge of the
Wash's soil and water make-up. The
Mormons had encountered the alkali
(saleratus), as did the builders of Las
Vegas Stadium, which is situated in the
heart of the Wash. Las Vegas remained
a railroad and agricultural service center
until 1931 when gambling was legalized.
Growth began with the construction of
the Hoover Dam and the formation of
Lake Mead. There is probably nothing
of historical (tangible) significance in
Las Vegas Wash, except for the ruins
of the so- called Mormon fort in the
City of Las Vegas, at the extreme upper
end of the Wash. The building of subdivisions
and roads have greatly defaced the upper
end of the Wash, and it may well be
impossible to find additional ruins of
former structures of the Mormon Mission
and Las Vegas Ranch.
POPULATION
Over the past fifty years the population
of Clark County has increased from less
than 5, 000 people in 1920 to over 270, 000
people in 1971. The high growth rate
has been particularly pronounced during
the last two decades. Rapid growth and
varying opinions as to when growth may
level out have produced a wide range of
estimates for future population.
During the past two decades, planners,
consultants and governmental agencies
have made projections of the growth in
population for Clark County. For the
year 2, 000, these estimates vary from
a low of 500, 000 people in the Valley
to a high of 1, 500, 000 people. Of these
projections, only the report entitled
"Population Projections, Clark County,
-------
HISTORICAL AND PROJECTED POPULATIONS
OF THE LAS VEGAS VALLEY AND CLARK COUNTY, NEVADA
POPULATION COMPONENT OF LAS VEGAS VALLEY
YEAR
HISTORY*
1920
1930
1940
1950
1960
1970
PROJEC-
TIONS**
1973
1980
Minimum
Medium
Maximum
1990
Minimum
Medium
Maximum
2000
Minimum
Medium
Maximum
CLARK
COUNTY
4,859
8, 532
16,414
48,289
127,016
273,288
331,700
420, 000
435,000
460, 000
560, 000
600,000
650,000
700,000
750,000
850,000
LAS VEGAS
VALLEY
122,957
268,065
316.725
403.000
421,000
446,000
530,000
565,000
621,000
661,000
700,000
805,000
LAS VEGAS
64,405
125,787
135.355
185,000
190,000
202,000
244,000
262,000
284,000
275,000
295,000
335,000
UNINCORP- NORTH
ORATED
AREA LAS VEGAS
27,605
89,667
122,320
144,000
152, 000
159,000
187,000
196,000
214,000
274,000
284,000
309,000
18.422
35,216
41,400
55,000
58,000
61,000
76,000
82,000
91,000
86,000
91,000
111,000
HENDERSON
12,525
16,395
17,650
19,000
21,000
24, 000
23,000
25,000
32,000
26, 000
30. 000
50, 000
*Bureau of the Census, Department of Commerce
** Clark County Regional Planning Council projection with modification to North Las Vegas
and unincorporated areas made by NECON.
104
-------
Nevada 1980-2000" prepared by the
Clark County Regional Planning Council
(CCRPC) has been approved and adopted
for utilization among the local govern-
ments within the regional planning juris-
diction. The distribution of population
within the County by the year 2000 is still
open to question. The CCRPC has calcu-
lated that if the median projection of
750, 000 people were to inhabit Clark
County in 2000, 93% (700, 000) of the
population would be in the Las Vegas
Valley. Extrapolating these population
components for the Las Vegas Valley
out, 295, 000 people would be in the City
of Las Vegas, 284, 000 would be in the
unincorporated areas, 91,000 would be
in North Las Vegas and 30, 000 would
be in Henderson.
The distribution of permanent population
within Las Vegas Valley is based on
CCRPC staff estimates with some modi-
fications by the engineering consultants,
Nevada Environmental Consultants
(NECON), to reflect changes in population
distribution between the City of North
Las Vegas and the unincorporated area.
This modification is made to adjust for
a recent annexation annulment.
Annexations, governmental consolidations
or the development of totally planned
communities, similar to that currently
being considered in Henderson, could
materially affect the distribution of popu-
lation among the various governmental
jurisdictions. Recent demographic pro-
jections for the City of Henderson suggest
that the city population could approach
105
44,000 people by the year 2000, and that
the new planned communities of Green
Valley and Lake Adair could increase
the population of the Henderson area to
159, 280 by 2000. Henderson presently
represents approximately 5.4% of the total
Las Vegas Vllley population, and is pro-
jected to maintain 4. 3% of the Valley
population in the year 2000 based on
CCRPC figures. If future populations
shifted to the Henderson area, this
distribution percent could change
significantly.
In addition to the permanent population,
there is present in the Las Vegas Valley a
large transient population. A substantial
portion of demand placed on public ser-
vices comes from this tourist and transient
segment. Transient population for 1973
showed a winter low of about 29, 000
people, a summer high of about 57, 000
people and a daily average transient
population of about 45,400 people.
Limited data on transient population
suggests that the total population in
Las Vegas Valley at any one time will be
about 109% of the permanent population
during winter months, about 118% during
summer months and, on the average,
about 114% of the permanent population.
Generally speaking, each unit of govern-
ment believes it will attract a somewhat
larger portion of the total growth than
has been shown by the distribution on
Table 14.
Throughout the formulation of the 1974
Wastewater Management Project sub-
-------
2,000,000
1,500,000
1,000,000
900
800
700
600
500
400
300
200
Q
o
a.
100.000
90
BO
70
60
50
40
30
20
10,000
Maximu m
I960
1970
1980
1990
2000
SOURCES.
YEAR
1. Bureau of the Census, Department of Commerce
2. Clark County Regional Planning Council
3. NECON
HISTORICAL AND PROJECTED
POPULATION CURVE FOR
LAS VEGAS VALLEY, NEVADA
106
-------
mittal, the applicant has utilized for
planning purposes the Clark County
Regional Planning Council's year 2000
medium population projection of 700, 000
for Las Vegas Valley. Since the ultimate
sizing of facilities may not necessarily
reflect this figure due to other environ-
mental quality considerations (i.e. , air
quality assimilative capacity to meet
standards within the Clark-Mojave-Yuma
Interstate Air Quality Control Region),
EPA will be continually reevaluating this
projection through its other planning and
regulatory programs for environmental
compatibility.
LAND USE
Since the 1950's Nevada has been one of
the Nation's fastest growing states, mov-
ing from a population of 160, 000 in 1950
to 489, 000 in 1970. The tendency has
been for settlement in the State's two
largest cities, Las Vegas and Reno. Las
Vegas became Nevada's largest city in
I960 and by 1970 its population had al-
most doubled to approximately 126, 000.
This growth has been partly the result of
the tremendous movement of people into
the western states. Ever since Nevada
legalized gambling, the prime element
in the economic development of the State
was established. Americans, with money
and free time, have made the Las Vegas
area of Clark County principally a recrea-
tion center and use of the land has been to
satisfy the needs of recreational pursuits.
With tourism as the main industry, min-
ing and agriculture have become secon-
dary.
Regional Land Use
The land area of the Lower Colorado
Region is classified as cropland, range-
land, forest and woodland, urban, and
a small acreage is for miscellaneous use.
Land ownership within the Region is
unique in that more than half is in pub-
lic ownership and only a small percentage
is private. About half the private land
is in Indian trust. The bulk of the land
in this Region is in pasture and range
with a small percentage in urban, trans-
portation, utilities, etc.
Recreation and tourism have grown into
a multimillion dollar industry in the
Region. The outdoor recreation oppor-
tunities provided by the forest, moun-
tain, desert and water areas have been
an important factor in this expanding
industry.
The location and amount of the Region's
irrigated cropland area is determined by
the availability of suitable irrigation
water, in terms of both quantity and
quality. This is especially true in the
desert area where the nearly year-long
growing season makes this area ideal
for irrigated crop production. With the
exception of the desert areas, irriga-
ted farming has developed primarily
along major streams where soils are
productive, have uniform slopes, and
where suitable water is available.
The range resource contributes substan-
tially to livestock production, long one of
the major industries, within this Region.
Two broad types of rangeland are used
for grazing: ephemeral and perennial.
107
-------
The ephemeral rangeland is in the de-
sert below the elevation of 3, 000 feet.
The average annual precipitation is less
than 8 inches; however, precipitation
varies widely from year to year. Large
volumes of annual grasses and forbs,
which provide good livestock forage,
are produced during above-normal
spring and summer rains. The peren-
nial-type rangeland provides a more
dependable, perennial-type forage. More
precipitation at higher elevations increases
forage quantity and quality in these areas
above 3, 000 feet elevation.
Timberlands can be found on national
forests, on Indian reservations, on land
owned by states and counties, by farmers
and ranchers, or owned by timber com-
panies and other private operators.
Growing stock suitable for saw timber,
paper pulp, poles, fuel, and other forest
products are the main timber products,
The commercial forest lands provide
some of the better livestock ranges.
They provide important habitat for wild-
life and coldwater fisheries. The com-
mercial forest areas are popular for
recreation, and their natural beauty has
important scenic value.
Urban and industrial developments occupy
a small percentage of land in the Region.
Individual developments range in size from
the acreage of Las Vegas to small unin-
corporated towns of less than a square
mile. In general, these lands are not
compatible with other uses; with the ex-
ception of recreation use. The larger
urban developments have recreation
areas reserved within their boundaries.
Although low-grade mineral deposits occur
over large areas, a very small percentage
of the Region's lands are actually used
for mineral production. While small in
size, these lands are intensively used.
Their economic importance is great;
their compatibility with other uses is
small; and they are, almost entirely,
in private ownership.
Transportation and utilities have kept
pace with the rapid regional growth.
Land used for roads, railroads, and
airports is generally excluded from
other land uses, but telephone, canal,
electric power, and pipeline rights-of-
way often modify existing uses and may
produce benefits not previously present.
Lands within the Region that are used
for military and related purposes, con-
sist of 0.5 million acres in Nevada.
A small percentage of these lands is
in areas suitable for urban expansion
and/or surrounded by intensively used
agricultural land. The majority of these
lands are barren desert or semi-arid
mountainous terrain.
Watershed Management Problems
More intensive use of the land resources
has created a multitude of watershed
management problems including:
increased soil erosion, accelerated
sediment production, reduced produc-
tivity, increased flood damage, and
degraded water quality. High yielding
108
-------
mountain watershed lands more and
more are regulated for water yield
in order to help fulfill the ever-increas-
ing water requirements of the Region.
Sixty percent of the land needs land
treatment and management for erosion
control and sediment yield reduction.
Danger from wildfire on the forest and
rangelands usually is present some place
in the Region during every month of the
year. Problems and responsibilities for
wildfire protection and control are mul-
tiplying due to the development of small
communities, expanding urban, and public
use developments scattered throughout
the forest and rangelands.
LAND USE IN THE LAS VEGAS VALLEY - 1972
Use
Single family
Multiple family
Commercial
Industrial
Public
Quasi-public
Parks
Total
Acres
16,310
2,820
3,570
2,080
15, 170
2,650
2, 390
44, 990 acres
Source: NECON - Water Quality Management Plan, Draft
(March 1973).
Area Land Use
Within the Las Vegas Valley the three
major urbanized areas consist of the
Cities of Las Vegas , North Las Vegas
and Henderson. These cities encompass
approximately 162.2 square miles of the
1, 800 square miles in the Las Vegas
Valley.
In 1968 the Clark County Regional Plan-
ning Council adopted the "Coordinated
General Plan for the Las Vegas Valley",
and a "Land-Use Element - Coordinated
General Plan" in 1971. In the Coordi-
nated Plan, future land uses in the Las.
Vegas Valley were projected from 1975
to 2000 at five year intervals, with the
2000 figures based on an estimated popu-
lation of 700, 000 people.
The City of North Las Vegas is essen-
tially a "bedroom" community to Las
Vegas, and also satisfies the urban
needs of personnel at Nellis Air Force
Base. Nellis Air Force Base is pri-
marily a pilot training facility whose
population and growth depend upon the
United States Air Force.
Boulder City began as a housing facility
for construction workers building Hoover
Dam. Incorporated in I960, Boulder City
is unique to this area in that it does not
allow gambling. The main "industry" is
recreation, Boulder City being five miles
from Lake Mead.
109
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PROJECTED LAND USES IN THE LAS VEGAS VALLEY - 2000
Use
Low density residential
High density residential
Commercial/industrial
Parks and recreation
Agricultural
Total
Acreage
56,700
13,045
30,275
9,430
2,000
111,450 acres
Source: Clark County Regional Planning Council, 1973
Henderson began as a housing facility for
Basic Magnesium, Inc. during World War
II, and is still an industry-based city
also providing some tourism and recrea-
tional facilities. The Basic Management,
Inc. complex, adjacent to Henderson,
now houses Stauffer Chemical Company,
the Flintkote Company, Titanium Metals
Corporation of America, Kerr-McGee
Chemical Corporation, Montrose Chemi-
cal Corporation of California, State
Stove Company and Jones Chemicals.
Since the development of the Las Vegas
Valley and portions of the Eldorado
Valley, man has ranged into the other
valleys of the study area. There has
been an attitude of "no value" toward
areas of the region not yet developed.
Dry Lake, Hidden Valley and Jean Lake
and those portions of Las Vegas and
Eldorado Valleys not yet developed,
have numerous trails cut by car or
motorcycle for convenience or sport
with no regard for the desert environ-
ment. Trash is found piled along many
dirt roads. Dry Lake Valley has been
used for cattle grazing and contains one
small railroad maintenance settlement.
Hidden Valley and Jean Lake are also
used for cattle grazing, but have very
low carrying capacity.
Use of Las Vegas Wash is high and diver-
sified. According to the U.S. Bureau of
Fish and Wildlife, there were an estima-
ted 50, 000 visits last year, the Wash
being used for: motor vehicle recreation,
educational field trips, bird watching,
hunting, hiking, horseback riding, and
dumping. When flying into Las Vegas,
the Wash is an immediate focus point
for the whole area. From the ground
the dense vegetation and vivid green are
offset somewhat by the piles of trash and
abandoned cars along the periphery of
the Wash.
110
-------
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Site Land Use
Ground-water Recharge Well Field and
Pilot Desalination Plant
At the present time, there is consider-
able open space around the Injection Well
Field, but it is rapidly disappearing on
the eastern boundary. Between Sahara
Avenue and Flamingo Road, west of Rain-
bow Road, is a newly-built housing deve-
lopment. North of Charleston Boulevard,
extending to the eastern boundary of the
site, is a residential area completely
built and occupied. The site is presently
bordered by a gravel company to the south
and west, the northern border showing no
signs of development. Also located on
the eastern boundary is a Nevada Power
Company substation. Present land use
appears to be primarily for scenic, tra-
vel and dumping purposes. Charleston
Boulevard passes through the study area,
leading to the Toiyabe National Forest
Area. Large piles of trash are observed
in this area along many dirt roads. Much
of Section 1 (640 acres) at the experimen-
tal recharge well site, has low density
housing with a population of approximate -
ly 60,000 people. There is some limited
commercial development on Sahara Ave-
nue and Decatur Boulevard and an elemen-
tary school on West Oakey Boulevard.
The alternative sections (2,560 acres)
are extensively developed with single and
multiple family dwellings, commercial
enterprises, schools, and recreation
areas. The population approximates
22,000 people.
Much of the land bordering the proposed
desalination plant site is presently owned
and maintained by the Las Vegas Valley
Water District. Numerous ground-
water wells are scattered throughout the
area. Two 10,000 gallon storage tanks
are located at the north end of the site
while an electrical substation borders
the area on the west. The area has been
substantially disturbed in the past and has
numerous roads criss-crossing the site.
A disjunct wash crosses the site from
west to east. Due to an extensive deve-
lopment of the area in the past, storm
flows are now diverted to a concrete
channel at the west of the site and there-
fore no longer enter the site.
Waste-water Collection System, Treat-
ment Plant, Deep Disposal Well Field
Areas and Sludge Disposal Site
Along much of the route for the collection
system the land has been disturbed by
man's activities in varying degrees. The
proposed route will follow existing high-
ways, dirt roads or rights-of-way along
most of the distance. It will also follow
a border of agricultural lands.
The site of the reservoir and treatment
facilities for Alternatives 1, 4, 6, 7 and
8 is scarred by dirt roads, litter and
motor-vehicle tracks. For Alternatives
2, 3 and 5 the site is approximate to a
major highway, the Las Vegas Stadium,
and a gravel pit operation. Much of the
area for the treatment plant in Alterna-
tive 10 has been extensively disturbed
112
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or altered by construction activities and
cattle and horse grazing. Portions of the
area are disturbed by a heavy equipment
yarding and other activities.
At the present time there is considerable
open space around the site of the sludge
disposal ponds. To the east the land
rises toward the rugged and colorful
Rainbow Garden and Lava Butte area.
In areas adjacent to the site, numerous
jeep trails and a recent pipeline excava-
tion crisscross and mar the area. The
site is bordered to the west and south
by Hollywood Boulevard and Telephone
Line Road. The Las Vegas Wash is
located immediately to the south and
west of these roadways.
Lands to be Irrigated
Major lands to be irrigated are existing
irrigation lands in the Valley, i.e. ,
parks, golf courses, and greenbelt areas.
The irrigation pipeline parallels existing
boulevards and avenues and roads. The
reservoir and pumping station have four
alternate sites with the land being used
in a variety of ways. The first location
is adjacent to two busy streets. A gas
station is across the street with a res-
taurant located on the diagonal corner.
The second is in the parking lot of the
Cashman Field and Elks Stadium. Deve-
lopment surrounding this site is residen-
tial on the south, the temporary City
Hall on the west, the Field and Stadium
on the east, and a commercial area on
the north. The third site is bounded on
two sides by a golf course, and on the
third by the Department of the Interior's
National Bighorn Sheep Headquarters.
A residential area is located across
Decatur Boulevard. Across from Mc-
Carran International Airport is the site
for the fourth reservoir. McCarran is
the only development near this site,
and it is very scarred and littered.
Refer to Figure 6 and Figures 28'
through 36 in Chapter 2.
Dry Lake Valley
Located at Dry Lake, in the northeastern
portion of the Valley, directly west of •
the Union Pacific Railroad, is a small
occupied settlement, with between 10 and
16 residents. Also located on the eastern
side of the Valley is a power line trending
northeast to southwest. A major portion
of this Valley is publicly owned land,
with small scattered areas of privately
owned land on the east side of the Valley.
The present use of this Valley is for
dumping, off-road motor vehicle recrea-
tion, enjoyment of scenery and travel.
Numerous car and motorcycle tracks are
seen crisscrossing the Valley. The
immediate environment of dirt roads off
the frontage road paralleling the Valley
is littered with abandoned cars, washing
machines and other assorted trash.
Cutting through the easternmost portion
of the Valley, running north-south, is
Interstate 15, the freeway from Salt
Lake City, Utah, Las Vegas and Bar-
stow, California. Travel along this
route is moderate. Paralleling this free-
way is the main line of the Union Pacific
113
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Railroad. Crossing the south end of the
Valley is Highway 93, a sparsely traveled
road, leading to Ely. Also located in
this Valley are powerlines leading to
Las Vegas and to Los Angeles.
There is an existing Desert National Wild-
life Range located just west of Highway
93. This area is primarily a refuge for
Desert Bighorn Sheep. It is presently
proposed to include this area in the
National Wilderness Preservation System.
The area comes within several miles of
the Dry Lake evaporation ponds and the
proposed Allen Power Plant.
Eldorado Valley
Located in the northern portion of this
Valley, adjacent to Highway 95, is a
single ranch and mining operation. The
northeastern portion of the Valley which
could be affected by an alternative is
owned by the City of Boulder City. The
remaining lands in the Valley are under
the jurisdiction of the Bureau of Land
Management. There is little evidence
of motor vehicle recreation or dumping
in this Valley. The Valley's main use
is for power line maintenance, scenic
and travel. Highway 95 to Searchlight,
Nevada crosses through the middle of
this Valley. Located to the northeast
side of this Highway is a large pet ceme-
tary which evidences a great amount of
use. There are three sets of power lines
crossing the Valley, trending east-west,
and a power relay station located in'the
southeastern portion of the Valley.
Jean Lake
All the lands that could be affected in this
Valley are under the jurisdiction of the
Federal Bureau of Land Management.
There are two cattle impoundments with
wells located in the study area. The pre-
sent use of this Valley is for grazing
cattle, limited dumping and motor vehi-
cle recreation. Little regard for the
desert environment has been demonstrated
in this Valley, evidenced by the large
amount of overgrazed land, the motor-
cycle tracks crisscrossing the whole
Valley and numerous car tracks. Aban-
doned cars and some trash are found along
the dirt roads at the northern end of the
Valley. Highway 91 passes by the ex-
treme northern portion of the Jean Lake
area with Interstate 15 directly west of
Highway 91.
Hidden Valley
This whole Valley is publicly owned land.
Motor vehicle trails crosscross the whole
Valley, and it has been heavily over-
grazed. There are two cattle impound-
ments with wells. The Valley is not
visible from any road.
HOUSING
According to the U.S. Census figures
of 1970, housing in the Standard Metro-
politan Statistical Area (SMSA) of Las
Vegas, consists of 92, 815 year-round
units. The construction boom during
the last few years has begun to slow
although the rte.e in vacancy factors
114
-------
indicates that residential units already
available, are enough to fulfill the area's
short-term needs. Apartments in the
Las Vegas area have climbed to more
than 7% vacancy factor. Residential
permits for new construction have de-
clined 42.9% in the first quarter of 1974.
TRANSPORTATION
Excellent transportation facilities service
the Las Vegas Valley. Passenger trans-
portation in all forms has been empha-
sized in recognition of the many available
tourist and recreational attractions.
Dollar volume for construction county-
wide has shown an increase primarily
due to the expansion of tourist-oriented
facilities. According to statistics for
1974, the Las Vegas expansion continues
with 3, 330 hotel and motel rooms cur-
rently under
Most of the major airlines serving the
West have flights to Las Vegas, including
nonstop flights from the east coast and
the mid-west. McCarran Field is an
"international" airport which permits
foreign flights to fly directly to Las
Vegas without prior stops in the United
-------
States for customs and immigration con-
trol. More than 30% of Las Vegas'
eight-and-a-half million annual visitors
arrive at the airport, which is served
by seven major airlines and various
supplemental carriers. McCarran's
constant growth relates directly to the
rapid population increase and the ever-
increasing number of visitors. A
thirty million dollar uplift program is
due for completion in the immediate
future.
Las Vegas is on the main line of the Union
Pacific Railroad between Los Angeles and
Salt Lake City and offers excellent trans-
continental freight service. Community
leaders and AMTRAK officials are at-
tempting to revitalize railroad service to
Las Vegas. The biggest problem at the
present time is the scarcity of operable
equipment. This mode of transportation
could be a great asset in servicing the
Southern California influx as each trip
could handle between 600 and 800
passengers.
Bisecting Las Vegas from the north by
northeast, is Interstate 15, an exten-
sively controlled network (freeway) that
connects Southern Nevada to the rest of
the United States. This freeway system
extends in the southerly direction through
San Bernardino, California where its
number changes to 1-10 and connects to
all points in Southern California. This
freeway system accounts for the majority
of truck lines and auto traffic into the
City. Bisecting Las Vegas from north
to south, is the twin system of U.S. 95
and U.S. 93.
An inner city shuttle for the visitor is
being contemplated. Moving people on
an overhead tram above the congested
traffic, it would, if approved, be the
only system of its kind in the world.
Its sinewy rail would follow a route from
McCarran International Airport, along
the Strip, to a central point in down-
town Casino Center. Stops are proposed
at each major resort hotel on the Strip
and the Las Vegas Convention Center.
EMPLOYMENT
The U.S. Department of Commerce has
prepared employment projections, by in-
dustry, for the Las Vegas Valley for the
period 1970 to 2020. These projections
indicate an anticipated population of
588, 200 by the year 2000. The regionally
adopted medium population planning pro-
jection for Las Vegas Valley is 700, 000
by year 2000. Accordingly, the Depart-
ment of Commerce employment projec-
tions have been adjusted to coincide
with regionally adopted population pro-
jections for the years 1980, 1990 and
2000. Adjusted employment projections
are shown on Table 15.
The importance of tourism is underscored
by the 1970 employment statistics which
show the service industry, consisting prin-
cipally of hotels, gaming and recreation,
to be the top area employer, accounting
for 42% of total employment. The next
largest employers in 1970 were whole-
116
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POPULATION-' (Thousands)
PARTICIPATION RATIO**
TOTAL EMPLOYMENT-' (Thousands)
MINING
CONTRACT CONSTRUCTION
MANUFACTURING
TRANSPORTATION AND PUBLIC UTILITIES
TOTAL TRADE
FINANCE, INSURANCE AND REAL ESTATE
SERVICE INDUSTRIES
GOVERNMENT
OTHER NON- AGRICULTURAL
AGRICULTURAL
HISTORY©**
I960
123.0
.44
53.7
0.4
3.7
2.6
3.8
8.4
1.4
20.9
6.2
5.8
0.5
1970
268.1
.45
121. 1
O.I
7.4
4.3
7.3
20.7
4.2
51.0
16.2
9.6
0.3
PROJECTIONS ©"*
1980
421.0
.41
173.5
O.I
14.1
11.1
9.9
30.4
7.3
81.2
19.2
*
0.2
1990
565.0
.42
239.0
O.I
17.9
14.7
13.7
43.8
10.8
112. 1
25.7
•
0.2
2000
700.0
.41
287.6
O.I
21.5
17.8
14.2
51.4
14.9
137.9
29.6
•
0.2
• Included in other numbers on this table.
** All numbers except Participation Ratio are given in thousands; Participation Ratio is the ratio of total employment to total permanent population.
SOURCES: (T) Nevada Employment Security Department
(2) NECON odjustmenti lo U S Deportment of Commerce projections
117
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FISCAL YEAR
HISTORY Q
1959
I960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
Average Annual Compound Interest Growth
PROJECTIONS (D
I960
1990
2000
CURRENT DOLLARS
91,033,938
106,503,378
108,478,255
122,633,158
137,291,416
152,350,481
163,209,101
179,018,338
199,056,250
227,437,087
287,642,376
352,552,000
373,242,526
417,662,387
502,500,000
12.5%
CONSTANT 1959 DOLLARS
91,033,938
104,795,216
105,421,045
117,803^226
. 130,257,510
142,250,068
150,008,365
159,695,217
172,045,160
189,058,260
228,287,602
267,085,000
272,439,800
292,071,595
339,756,590
9.5%
365,000,000
545,000,000
715,000,000
SOURCES- (jj Nevada Gaming Commission
(2) Current Population and Economic Statistics, 1973 by Clark County Regional Planning Council
.
£
o
< <
0
O -
4)
its
-------
sale and retail trade at 17% and govern-
ment at 13% of total employment.
Gross gaming receipts provide a growth
index for the service industry and for the
entire metropolitan area. Historic and
projected gross gaining receipts for the
year 2000 are expected to be 2. 68 times
that received in 1970. It is anticipated
that population during the same period of
time is expected to increase by a factor of
2. 61. Thus, it is concluded that the ser-
vices industry will maintain its dominant
role through the year 2000. (See Table 16).
In addition to growth precipitated by the
service industry, very favorable tax laws
are in effect in Nevada which benefit com-
merce and industry. The "Free Port"
law encourages the warehousing and manu-
facturing of goods "in transit" by granting
a tax-exempt status to such goods. This
and other favorable tax laws are an induce-
ment to many potential employers and
manufacturers.
The Federal government has a number of
programs which are quite significant to the
economy of Southern Nevada. Most impor-
tant of these are:
(1) Nellis Air Force Base, a training and
development center for military aircraft.
(2) The Atomic Energy Commission's
Nevada Test Site, which operates with
a large budget. The Atomic Energy
Commission operations in Southern
Nevada include research and develop-
ment on nuclear explosives, both war
and peace oriented. Among other faci-
lities, the AEC operates the evaporation
station near Lake Mead. The Radiologi-
cal Health Laboratory studies the physio-
logical effects of radiological exposure.
(3) The Lake Mead National Recreational
Area.
As of September 1973 total employment
was 145, 600, only 200 fewer than the all-
time record high set the previous month.
In September 1972, total employment
stood at 132, 500. Unemployment totaled
about 8, 000 persons or a rate just under
6% during September 1973. The rate is
down 1% from 1972 figures.
HISTORICAL SITES
Las Vegas was a part of the Arizona
Territory when Nevada was admitted to
the Union, While it had been a watering
place for south-bound emigrants who tra-
veled the Old Spanish Trail, it never
distinguished itself except as an outpost
of the Mormon colonization movement in
1885. Within the Las Vegas city limits
may be found the Mormon Mission on
Washington Avenue and the original
Springs on Fremont Street. The site of
the Old Spanish Trail follows Las Vegas
Wash. Much of the area's history is
stored in its "ghost towns. " They were
creations and victims of the mining and
railroad industries. A number of old
mine shafts are located in Eldorado
Valley, among them, the "Goodsprings
Mine" of 2899 and the "Nelson Mine" of
119
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1857. The ghost town of Aliunite is
between Henderson and Boulder City,
while the site of the Potosi is in the Blue
Diamond area southwest of Las Vegas.
Other ghost towns are in Eldorado Valley
but their remains have virtually vanished.
Other historical sites in the Las Vegas
region consist, for the most part, of old
mines and ranches. An example of the
latter is the Kyle Ranch, established in
the 1880's and located in North Las Vegas
on Losie and Carey Streets, (communi-
cation with Dr. Roske of the Southern
Nevada Historical Society). Throughout
the Region, artifacts are found of the
area's past Indian culture.
Period 1. Early Man
These cultural remains are represented
by finds at Tule Springs, where a few
artifacts were recovered by excavators
from deposits dated between 10,000 and
12, 000 years ago. Elsewhere in the Mo -
jave Desert cultural remains from this
period are found on the margins of dry
lake beds similar to Jean, Hidden, El-
dorado, and Dry Lake beds. Occupa-
tion also believed to date from this period
is often found on higher level surfaces
and is known from Whitney Mesa and
margins of Las Vegas Wash.
The archaeology of the Las Vegas Valley
and surrounding areas is little known.
No major archaeological investigation has
been undertaken within this area for more
than five decades. (The one exception
to this is the Tule Springs expedition,
whj.ch was uniquely unsuccessful in finding
archaeological remains, probably due to
the locality of the major excavations. )
Archaeological investigations in neighbor-
ing areas, and unpublished investigations
undertaken in the general area of Las
Vegas Valley indicate that archaeological
resources may be plentiful and important
in the areas to be affected by any one of
the alternate plans. There were at least
five periods of occupation in the Mojave
Desert, all with distinct cultural expres-
sion and all are probably represented in
archaeological remains in Las Vegas
Valley and adjacent areas. These periods
are briefly discussed below:
Period 2. Pinto Culture
This culture apparently dates between
9, 000 and 4, 000 years ago, and is repre-
sented by surface finds at Tule Springs
and at Corn Creek Dunes. Remains of
the Pinto Culture are found along extinct
water courses and less often around dry
lakes, springs, and occasionally else-
where in what now appear to be places
that are unlikely to be occupied by man
lacking highly developed technology.
Period 3. Gypsum Culture
Gypsum culture dates from 4, 000 to 1, 500
years ago. This culture is known from
Gypsum Cave and a number of sites else-
where in the Mojave. These are mostly
rock shelters or middens near springs
and streams that were flowing during
120
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historic times. Some materials resem-
bling those of this period have been re-
ported by amateurs and recently by col-
lege students from Eldorado Lake and
Paradise Valley.
Period 4. Pueblo Occupation
RECREATION
All within 100 miles of Las Vegas, are
more than 48 public and private camp-
grounds, totaling 3, 588 individual camp-
sites. These are operated by the U.S.
Forest Service, National Park Service
or the Nevada Park System.
This occupation dates from 1, 500 to 800
years ago and it characterized by Pueblo
remains in the Las Vegas Valley. Sites
dating from this period are known to be
located near historically flowing springs
such as Big Springs. They are found in
Paradise Valley and in rock shelters at
higher elevations around the valley.
Period 5. Paiute Culture
Paiute' culture dates from about 800 years
ago to the time of European settlement.
The Paiute utilized both the valleys and
mountains of this area, and their remains
are known from Duck Creek and Para-
dise Valley, near Tule Springs, Bird
Springs, and numerous small sites at
higher elevations.
It is likely that most, if not all, of these
cultural periods known for the Mojave
Desert and Las Vegas Valley would be
represented by sites on the alternate
routes proposed by the Las Vegas Valley
Water District. The archaeological re-
mains are nonrenewable resources.
Lake Mead National Recreation Area,
fourth largest in the National Park Sys-
tem, with the biggest accommodation
of campsites, is just a half-hour drive
from the casinos. Formed by monolithic
Hoover Dam and fed by the Colorado
River, the lake's 550 miles of shoreline
enjoys a twelve-month season. The
area encompasses over 3,000 square
miles of lake area and surrounding
desert environment, and provides both
local and out-of-state visitors with
fishing, boating, swimming, and other
forms of recreation. Nearly 3-1/2
million persons spent one or more days
in the Lake Mead area in 1973. As of
June 1974, visitors to Lake Mead totaled
326, 412 for the month and 1, 612, 096
for the year to date.
Toward the north end of the lake is the
Valley of Fire State Park, a 55, 000-acre
ecological "museum" and recreation area.
Nature began work on the valley sometime
around the "Ice Age", when the terrain
was still lush green and well-watered.
Rock carvings found in the vicinity date
Indian civilization as far back as 1, 500
B.C. Camping and picnicking sites, like
the roads, are designed, located, and
oriented to offer both intimacy and a
panoramic view of the valley.
121
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Away from the desert terrain, and jutting
skyward from the floor of the arid Amar-
gosa Desert, stands 12, 000-foot Mt.
Charleston, only an hour's drive from
downtown Las Vegas. In the winter time
the verdant slopes become a playground
for skiers. New facilities in the area
have made it the fastest growing recrea-
tion outlet in Southern Nevada.
Nearly every major hotel boasts cham-
pionship tennis courts and for golf
courses. Spectators are treated to
maJor golf and tennis tournaments,
most having celebrity rounds. With
the almost constant sunshine, swimming
and sunning around the hotel pools are
an intricate part of Las Vegas by day.
Visitor and Visitor Use - 1973
Lake Mead Recreation Area - 5, 534, 515
Hoover Dam Guided Tours - 638, 315
Mount Charleston - 459, 600
Valley of Fire - 232, 000
Valley of Fire Visitor Center - 60, 000
Lost City Museum - 181, 000
In addition, the Bureau of Land Manage-
ment (BLM) administers over 3 million
acres of public lands (greater than 51%
of the land in the County) within Clark
County. Approximately 183, 250 acres
of this BLM land has been classified as
having recreational, protective or scenic
qualities.
UTILITIES
The Southwest Gas Corporation, a. Las
Vegas-based natural gas utility which
serves Nevada, California, and Arizona,
increased its revenues during 1973 by 11%
over the previous year. The 1974 custo-
mer growth pattern is expected to con-
tinue with the addition of nearly 8, 000
residential and commercial customers
with most of the increases in the utility's
Southern Nevada Division. Natural gas
usage during the year 1973 for gas sales
(l.OOOcu. ft.) was 40, 681, 508, and
customer accounts totaled 48,328.
The Nevada Power Company is an inves-
tor owned utility development. In 1929
the Consolidated Power and Telephone
Company became known as the Southern
Nevada Power Company. The name -was
subsequently changed to Nevada Power
Company in 1961.
The directors of the old company were
instrumental in adding the "Nevada Amend
ments11 to the Swing-Johnson Act which
gave Nevada the right to share in the
water, power and revenue from Hoover
(Boulder) dam. This source of 263 mil-
lion kilowatt-hours and 87,375 kilowatts
served the electric needs of Las Vegas
for the next 16 years.
It is well to point out that the energy
received from Hoover Dam, which re-
presented 100 percent of the requirement
in 1953, represented in 1970 only about
11 percent of the company's total needs.
122
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Vio ^*-.~** ^ s'"-°"
ions O' r1ei*iion» of
PRINCIPAL TRANSMISSION LINES
YEAR 1980
500 KV
345 KV
287 KV
230 KV
CONNFCTiNG LINES
L»NFS
20 0 2O 40 SO 80
' r-t t-i ' 1 >- 1 i
SCALC OF MM.ES
figure 25
CO
-------
In 1955 the company added its first gas-
fired steam electric generating unit and
plant of 50, 000 kw. At the end of 1965
the company was operating a total of three
steam generating stations and a diesel
peaking plant to serve customers within
the Las Vegas area.
for anticipated growth in the downtown
area. Telephones in service during the
year 1973 for the Southern Nevada
Division of the Central Telephone Com-
pany was 254, 978, and for the Continental
Telephone Company of Nevada (Hender-
son) the total was 7, 818.
The Las Vegas Division of the Company
shows an 11% electric energy use increase
in 1973 over the previous year and its
growth plans go well into the 1980's to
keep up with the demand of electrical
energy usage. The electric utility has
already added to its producing capabilities
once in '74, as a participant in the Navajo
Power Project in Northeastern Arizona,
as it will also do in 1975. Electric energy
during the year 1973 for sales (1,000 Kilo-
watt-Hours) for residential was 1,792,688,
commercial and industrial 1,983,701 and
other 290,422. Customer accounts to-
taled 108,088.
The Southern Nevada Division of Central
Telephone Company is kept in a constant
state of growth as its telephone in ser-
vice increased nearly 12% over 1972 (this
figure includes four smaller companies
in outlying areas). In 1974 Central Tele-
phone is anticipating main station gains
of 23, 000 additional units; in conjunc-
tion with this, the company has budgeted
$28 million in new construction to keep
up with the increased demand. The
five-year forecast indicates that con-
struction expenditures will remain on
the same yearly level. In 1974 the
downtown office cut in a 10,000-line
electronic switching system to provide
The Las Vegas Valley Water District
expects to spend $29 million in the next
four years in order to keep pace with
the anticipated growth of the community.
Land acquisitions will cost about $1.3
million, and reservoir additions are
estimated around $8.8 million. Well
field expansion will cost approximately
$1.9 million and pump station installa-
tion costs are estimated to be $2.7
million. A projected $14. 3 million will
be required over the next four years to
install pipelines necessary to adequately
serve population increases. If projected
population increases materialize, the
second phase of the Southern Nevada
Water Project will be constructed by
early 1980. This phase will double the
capacity and will ultimately enable the
Las Vegas Valley to recieve full allo-
cation of Lake Mead water. Water dur-
ing the year 1973 for consumption
(thousands of gallons) totaled 26,911,366
and customer accounts totalad 54,013.
124
-------
PPO.IF CTfJ
*•; oc ?ooo
IOOO KV (i C
7M KV
7OO KV
'00 KV
545 KV
287 KV
230 KV
CONNECTING UNES
CROSSOVER LINES
A^ OF jwwe
I No attempt Hoi t>e*n -nod* »o tortcaii v>in»r
f'OnimilS'on foc-M'fs O* l*« fftO" 2 \0 (CV
Tronjmnvon lm«i umpM.ed m ronqttttd
PRINCIPAL TRANSMISSION LINES
YEAR 2000
SCALE OF MILES
figure 26
-------
WATER USE
Nevada has little usable surface water;
its primary sources of water being
ground-water reserves and the Southern
Nevada Water Project. The first phase
of the Water Project, nearing completion,
will provide 132, 000 acre-feet annually
by pumping Colorado River water from
Lake Mead for municipal and industrial
uses in the Las Vegas area. Completion
of the second stage construction should
occur before year 2000 and would utilize
most of the remainder of Nevada's
300, 000 acre-feet per year share of
Colorado River water.
Present depletion requirements for the
Subregion total nearly 1.29 million
acre-feet annually. Water withdrawal
requirements total about 2.98 million
a.cre-feet of which some 90% is for
irrigated agriculture. About 19% of these
requirements occur in Nevada. Future
water requirements in the Subregion show
depletion requirements increasing by
about a million acre-feet between 1965
and 2020, the largest increases occurring
in agriculture and municipal and indus-
trial demands. Significant increases
also occur in electric power and fish
and wildlife needs. By 2020, Nevada's
requirements are projected to rise from
251, 000 acre-feet per year to over
715,000 acre-feet, a.threefold increase,
due primarily to a rapidly growing
population.
Present demands on the supply of the
Colorado River below Lee Ferry, in
addition to the 1.3 million acre-feet of
present water requirements within the
Subregion, are for main stem reser-
voir evaporation, channel losses, system
spills, exports to the California Region,
and Mexican Treaty obligations. The
future water supply available to the sub-
region, without augmentation, is almost
entirely dependent on the depletions
caused by water resource development
in the Upper Colorado River Basin.
Water withdrawals in the lower main
stem Subregion show, for the 1965 level
of development, gross diversions of about
2.42 million acre-feet annually, including
more than a half-million acre-feet from
ground-water pumpage. Seventy percent
of these diversions were made below Im-
perial Dam. About 6% of the total with-
drawals were identified with uses other
than irrigation. The average annual ir-
rigation diversion in Nevada is estimated
at about four acre-feet per irrigated acre.
Much of the diversion is returned to the
River for reuse downstream. Nearly all
of the present diversions of surface water
from the mainstream of the Colorado
River are measured. Off-stream diver-
sions, principally from the Virgin, Muddy,
and White Rivers, and Kanab Creek, are
minimal. Surface water diversions to
the Las Vegas-Henderson-Boulder City
area and to the City of Yuma, Arizona
represent the bulk of uses for municipal
and industrial purposes. Current ground-
water pumpage in the Subregion is esti-
mated at about 525,000 acre-feet annually
of which about 80, 000 acre-feet are pum-
126
-------
WATER RESOURCE UTILIZATION
1969-1973
LAS VEGAS VALLEY
YEAR
1969
1970
1971
1972
1973
GROUNDWATER CD*
BILLION
GALLONS
28.26
27.88
27.84
22.84
22.73
ACRE
FEET
86,717
85,555
85,436
70,086
70,063
COLORADO RIVER ©
BILLION
GALLONS
10.99
11.16
13.39
21.25
24.43
ACRE
FEET
33,731
34,250
41,089
65,208
74,988
WASTEWATER©
BILLION
GALLONS
2.84
3.07
3.41
3.15
3.07
ACRE
FEET
8,717
9,431
10,454
9,663
9,427
TOTALS
BILLION
GALLONS
42.09
42.11
44.64
47.24
50.23
ACRE
FEET
129,165
129,236
136,979
144,957
154,478
SOURCES* (j) stote Enfli""'* Office, Division of Woter Resourc« - Los Vegai Valley Water Inventory (Annual Reports, 1969-1973).
Bureau cf Reclamation -Compilation of Records in Accordance with Article V of the Decree of the
Supreme Court of the United States in Arizona v. California Dated March 9, 1964 (Annual Report
thru 1972 and provisional records of the Colorado River Commission for 1973).
* Total fcmount of water pumped from the Las Vegas artesian basin.
127
-------
ped for municipal and industrial use.
72, 000 acre-feet is pumped in the Las
Vegas Valley.in Nevada, where pumpage
exceeds the probable recharge of 25,000
to 35,000 acre-feet annually. Other
areas of localized overdraft also exist.
Existing Water Uses and Distribution
Records of 1973 water consumption and
waste-water generation were compared
with the CCRPC 1973 population estimates
to obtain current water use factors. The
results of this comparison indicated that
the assumptions made for per capita water
and waste-water generation used in the
1969 Boyle CH2M Phase II report were suf-
ficiently accurate for the comparisons
in which they were used. For the pur-
poses of this study, a more current set
of per capita factors were developed for
various categories of water usage based
upon 1973 flow data and the CCRPC popu-
latfon estimates. Specific categories de-
scribed are as follows:
Residential and Transient
Parks and Public Facilities
Golf Courses
Agriculture
Heavy Industry
Commercial and Light Industry
Military
Power
WASTE -WATER FLOWS
Waste-water flows for 1973 are shown on
Table 20 for each of the more highly
developed areas of Las Vegas Valley.
The 1973 flows are based upon the mea-
sured flows into the City of Las Vegas
and the Sanitation District waste-water
treatment plants. Flows for the City
of Henderson are as estimated by the
Henderson Public Works Department
and represent the sum of the flows enter-
ing Henderson Plants Nos. 1 and 2.
During 1973, the City of Las Vegas waste-
water plant treated an average of 31.8
mgd (35, 600 acre-ft/yr). This average
flow included the 23. 1 mgd (25, 900 acre-
ft/yr) shown for the City of Las Vegas,
4.4 mgd (4,900 acre-ft/yr) from north
Las Vegas and 4.3 mgd (4,800 acre-ft/
yr) diverted from the unincorporated
area. The Clark County Sanitation Dis-
trict treated an average of 13. 2 mgd
(14, 800 acre-ft/yr) which is the balance
of the flow from the unincorporated area.
A long term contract between the City
of Las Vegas and the City of North Las
Vegas calls for the continued treatment
by Las Vegas of waste water from North
Las Vegas. Diversion of waste-water
flows from the unincorporated area to the
City of Las Vegas plant is a temporary
condition which will be discontinued upon
completion of expansions now (1974) under
way at the Sanitation District's waste-
water treatment plant.
128
-------
WATER USES
AND
SUPPLY DISTRIBUTIONS
LAS VEGAS VALLEY
PARAMETERS
WATER USED--
POTABLE WATER USED:
RESIDENTIAL AND TRANSIENT
PARKS AND PUBLIC FACILITIES
60LF COURSES
AGRICULTURE
HEAVY INDUSTRY
COMMERCIAL AND LIGHT INDUSTRY
MILITARY
TOTAL POTABLE WATER USED--
RECLAIMED WASTEWATER USED:
PARKS AND PUBLIC FACILITIES
60LF COURSES
AGRICULTURE
POWER
TOTAL RECLAIMED WASTEWATER USED'
TOTAL WATER USED:
WATER SUPPLIED:
6ROUNDWATER WITHDRAWALS
COLORADO RIVER DIVERSIONS
RECLAIMED WASTEWATER
TOTAL WATER SUPPLIED-
COLORADO RIVER DEPLETIONS' (Lai VtgoiVoltayoily)
NET DIVERSIONS
WASTEWATER RETURNED
NET DEPLETION:
HISTORY FOR YEAR 1973
WITH ESTIMATED JULY 1, 1973
POPULATION OF 316,725 PEOPLE©
ACRE FEET GD*
90,000
9,200
6,100
3,000
13,600
20,000
3,200
145,100
-0-
1,200
4,500
3,700
9,400
154,500
70,100
75,000
9,400
15.4,500
75,000
-43,000
32,000
BILLION GALLONS
29.32
3.00
1.99
0.98
4.43
6.52
1.04
47.2t
-0-
0.39
1.47
1.20
3.06
50.34
22.84
24.44
3.06
50.34
24.44
-14.01
10.43
SOURCES* Q) Current Population and Economic Statistics 1973, by Clark County Regional Planning Council. * Rounded to nearest 100 acre feat.
(T) Provisional 1973 records of the Colorado River Commission; Las Vegas Valley Water Inventory, 1973 by the State Engineer's Office;
1973 records of the Las Vegas Valley Water District.
table 18
-------
YEAR 2000
WATER NEEDS
AND
SUPPLY DISTRIBUTIONS
LAS VEGAS VALLEY
PARAMETERS
WATER NEEDS-'
POTABLE WATER NEEDS'
RESIDENTIAL AND TRANSIENT
PARKS AND PUBLIC FACILITIES
GOLF COURSES
AGRICULTURE
HEAVY INDUSTRY
COMMERCIAL AND U6HT INDUSTRY
MILITARY
TOTAL POTABLE WATER NEEDS?
RECLAIMED WASTEWATER NEEDS:
PARK AND PUBLIC FACILITIES
GOLF COURSES
AGRICULTURE
POWER
HEAVY INDUSTRY
TOTAL RECLAIMED WASTEWATER NEEDS:
TOTAL WATER NEEDED'-
WATER SUPPLIES-'
6ROUNDWATER WITHDRAWALS
COLORADO RIVER DIVERSIONS
RECLAIMED WASTEWATER
TOTAL WATER TO BE SUPPLIED'
COLORADO RIVER DEPLETIONS '{LoitogaiVblleyaniy}
NET DIVERSIONS
WASTEWATER RETURNED
NET DEPLETION
PROJECTIONS FOR YEAR 2000 ©
FOR MEDIUM POPULATION
OF 700,000 (2)
ACRE FEET*
212,800
10,000
6,000
3,000
32,200
46,900
7,700
318,600
1 1 ,000
9,800
8,500
39,500
-0-
68,800
387,400
50,000
268,600
68,800
387,400
268,600
-54,400
214,200
BILLION
GALLONS
69.34
3.26
1.96
0.98
10.49
15.28
2.50
103.81
3.58
3.20
2.77
12.87
-0-
22.42
126.23
16.29
87.52
22.42
126.23
87.52
-17.72
69.80
FOR MAXIMUM POPULATION
OF 805,000 (2)
ACRE FEET*
244,700
1 3 ,200
6,100
4,000
32,600
53,900
8,900
363,400
1 1,000
1 1,800
8,500
39,500
4.400
75,200
438,600
50,000
313,400
75,200
438,600
313,400
-65,700
247,700
BILLION
GALLONS
79.74
4.30
1.98
1.31
10.62
17.56
2.90
1 1 8 .4 1
3.58
3.85
2.77
12.87
1.43
24.50
142.91
16.29
102.12
24.50
142.91
102.12
-21.42
80.70
SOURCES' (0 Projections by NECON Staff.
* Rounded to nearest 100 acre feet.
(|) Population estimates by Clark County Regional Planning Council Staff.
table 19
-------
DOMESTIC AND COMMERCIAL
AVERAGE DAY WASTEWATER FLOWS
PRESENT AND PROJECTIONS
YEAR
PRESENT©
1973
Per Capita Flow(gpcd)
Actual Flow(mgd)
PROJECTIONS©
1980
Per Capita Flow(gpcd)
Minimum Flow(mgd)
Medium Flow(mgd)
Maximum Flow(mgd)
1990
Per Capita Flow(gpcd)
Minimum Flow(mgd)
Medium Flow (mgd)
Maximum Flow (mgd)
2000
Per Capita Flow(gpcd)
Minimum Flow (mgd)
Medium Flow (mgd)
Maximum Flow (mgd)
LAS VEGAS
VALLEY
144
46.8
ISO
60.6
63.1
66.9
154
81.7
87.2
95.6
157
103.9
II 0.0
125.8
WASTEWATER FLOW COMPONENTS OF LAS VEGAS VALLEY
LAS VEGAS
171
23.1
175
32.4
33.2
35.4
178
43.4
46.6
50.6
180
49.5
53.1
60.3
UNINCORP-
ORATED
AREA
133
17.5
140
20.2
21.3
22.3
145
27.1
28.4
31.0
150
41.1
42.6
46.4
NORTH
LAS VEGAS
106
4.4
NO
6.0
6.4
6.7
its
8.7
9.4
10.5
120
10.3
10.9
13.3
HENDERSON
100
1.8
105
2.0
2.2
2.5
110
2.5
2.8
3.5
115
3.0
3.4
5.8
SOURCES.'OBasedonWaittwater plant records for 1973 and CCRPC Staff estimates of
Population for 1973.
(?) Based on Projected Per Capita Flows by NECON and Permanent Poptilatioi
Projections shovn on TABLE
table 20
-------
EXISTING SANITARY FACILITIES
Collection System
Service Areas
Waste-water collection systems and asso-
ciated treatment plants serve the majority
of the urbanized area of the Las Vegas
Valley. Major waste-water systems are
operated by the Cities of Las Vegas,
North Las Vegas, Clark County Sanitation
District, and Henderson.
City of Las Vegas (Including North
Las Vegas)
The present waste-water systems of the
Cities of Las Vegas and North Las Vegas
are considered a combined system be-
cause they utilize some common major
interceptors and treatment facilities be-
longing to the City of Las Vegas. The
combined systems, now treating the
largest amount of sewage in the valley,
presently serve nearly all the population
of both cities. The treatment facility
receives municipal wastes from the
sewered portions of the incorporated
areas of Las Vegas and North Las Vegas.
The undeveloped areas lying within both
cities are subject to future development.
The extension of waste-water collection
facilities to serve this development will
be necessary. The areas of present
service and proposed future service are
shown on Figure 27.
The major portion of the sewer system
has been installed within the last 20 years.
The older sections of the collection system.
maybe experiencing some ground-water
infiltration. Most of this can be attributed
to poured joint connections for clay pipe.
With receding water tables, the effect
of infiltration may not be extensive, al-
though perched water from, irrigation will
undoubtedly continue to infiltrate these
older lines.
Population estimates suggest a population
approaching or exceeding 400, 000 persons
by the year 2000. This would require a
little over two times the present number
of service connections. The system will
probably require some future paralleling
of major interceptors or the construction
of relief sewers.
There are several existing problem areas
in the collection system within the city
limits. Some of these have been corrected
and a number are in process of being
resolved by relief connections, a sewer
relayment to appropriate depth, etc. At
present, additional sewerage facilities
are needed in the downtown area due
to the construction of high-rise hotels
in the past ten years. All of the new
high-rise office buildings also have been
built since 1964 and current planning
includes a downtown convention center.
This construction and its related de-
velopments require additional, and larger
capacity, trunk sewers to handle the ex-
panded uses of the downtown area.
132
-------
LEGEND
I Existing Service Area
1st Phase Expansions
«^ 2nd Phase Expansions
3rd Phase Expansions
4th Phase Expansions
v:Stp%f*
<» nfiFSFr^^
V*Jl%|j
.,"<^^'.•:".;>-».-* '«--' *—"x
i';;-K";.^'ii-j ' X /7l
•^ Existing Interceptors *
••• Proposed Interceptors *
HENOERSOM
figure 27
-------
While infiltration is not a problem, inflow
illustrates the result of a problem peculiar
to desert construction. Flash floods
damage or wash out portions of the local
sewer system. However, this type of in
flow is extremely intermittent in nature
and is not significant to the overall con-
dition of the collection system. Also, the
treatment facility is of sufficient capacity
to accommodate the increase in flows
occurring because of unusual and/or ex-
traneous conditions. Undesirable in flows
can be readily eliminated by the replace-
ment of curb inlets with properly designed
dry wells. This would mean an annual
decrease of flow into the treatment plant
of approximately 5. 0 million gallons per
inlet and would result in a savings in plant
operations.
Treatment Facilities
The City of Las Vegas1 waste-water treat-
ment plant consists of two, essentially
similar, high-rate trickling filter plants,
•operating at a nominal design capacity
of 30 million gallons per day, (mgd).
In 1973, the daily flow rates averaged
31.8 mgd. This included 4.3 mgd which
was diverted from the Clark County Sani-
tation District's waste-water collection
system. The County's waste-water plant
expansion should discontinue this flow
diversion. Even so, it is anticipated
that the City's plant will reach its design
capacity before the end of year 1975.
A study on recommended expansion of
the City's plant and a collection system
infiltration-in flow analysis is underway.
Waste-water discharges from this plant
may be described as high-quality secon-
dary effluent. Removal of biochemical
oxygen demand (BODs) for 1973 ranged
from 90% to 96%, with an annual average
removal of 93%. Removal of suspended
solids (SS) for 1973 ranged from 87% to
94%, with an annual average removal of
91%. A detailed description of the ef-
fluent characteristics was presented in
Table 2 in the section entitled WATER
QUALITY . A small portion of the treated
effluent is used for cooling water for the
Nevada Power Company's Sunrise Gene-
rating Station and for irrigation. The
remaining effluent is discharged directly
into the Las Vegas Wash.
System Administration
The Sanitation Division of the City of Las
Vegas1 Department of Public Works is
responsible for the administration, main-
tenance and operation of the City's waste-
water collection and treatment facilities.
The Department of Public Works' budget
is subject to the approval of the City
Commissioners. The Sanitation Division
includes the Waste-water Treatment Sec-
tion responsible for maintenance and oper-
ation of the City's Waste-water Plant,
which is manned round-the-clock, and the
Sewer Maintenance Section, responsible
for the waste-water collection facilities
City of North Las Vegas
The City of North Las Vegas operates
134
-------
and maintains the waste-water collection
facilities within its corporate boundaries
and discharges its collected waste water
to the City of Las Vegas' waste-water
system. North Las Vegas is giving
serious consideration to the construction
of a 3 to 4 mgd waste-water reclamation
plant. The plant as presently conceived,
would be an extended aeration activated
sludge plant. The area to be served by
this plant lies generally west of Inter-
state 15 and north of Carey Avenue.
Chlorinated effluent from the reclamation
plant would be used for irrigation of up-
wards to 1, 600 acres of parks and golf
courses, some planned unit developments
and Craig Ranch Country Club. One of
the larger areas proposed for irrigation
is the North Las Vegas Regional Park
where reclaimed waste water will also
be used to maintain a 40 acre lake.
Solids processing facilities would not
be included with the reclamation plant.
The City of North Las Vegas proposes to
discharge solids back to the interceptor
system for subsequent treatment at the
City of Las Vegas1 waste-water treatment
plant. This approach to solids handling
may be accomplished by mutual agreement
with the City of Las Vegas with appropriate
amendments to the existing sewer service
contract. Irrigation with reclaimed waste
water from this plant would require some
modifications to the in-valley irrigation
system described in Chapter 2.
Clark County Sanitation District
The Clark County Sanitation District pro-
vides waste-water and collection and
treatment facilities which serve the de-
veloped but unincorporated areas within
the Las Vegas metropolitan area, plus
the recent addition of Nellis Air Force
Base.
Collection System
The Sanitation District's existing and
projected waste-water collection system
is shown on Figure 27. The collection
lines generally extend from Nellis
Air Force Base on the north to Sunset
Road on the south and from Decatur
Boulevard on the west to the waste -
water treatment plant on the east.
The major trunk and interceptors
shown on Figure 27 are the backbone
of the Sanitation District's System.
Pipe sizes range from 4-inch single
residential laterals to 51-inch inter-
ceptors.
The District treats the second largest
amount of sewage in the valley. Popu-
lation projections indicate that by the
year 2000, the area served by the District
may grow to over 300, 000 persons and
may generate average daily waste-water
flows in excess of 40 mgd. This will re-
quire enlargement or paralleling of some
existing interceptor lines. Assuming de-
velopment proceeds in an orderly manner
and large areas of developable land are
not bypassed, it should be possible to
expand the collection system as required
to meet future demands at reasonable cost.
There are still many septic tanks in the
Las Vegas Valley.
135
-------
Treatment Facilities
maining effluent is discharged directly
into Las Vegas Wash.
The Clark County Sanitation District's
waste-water treatment plant is of the
high-rate trickling filter type with a no-
minal capacity of 12 mgd.
A 20 mgd expansion of this plant has
been undertaken by the applicant.
The waste-water treatment processes
employed in the plant expansion are the
same as those of the original plant.
The solids handling facilities are,
however, different. When the plant ex-
pansion is completed, all solids will
receive thickening, heat treatment,
vacuum filtration, and incineration. The
waste-water stream from the solids hand.-
ling process will be treated in an activated
sludge basin and returned to the plant in-
let structure.
This plant is operating under overloaded
conditions. The 1973 average daily flow
from the collection system was 17.5 mgd
of which 4. 3 mgd was diverted to the
City's plant for treatment, leaving 13.2
mgd to be treated. Removal of BODs for
1973 averaged 83%. Removal of SS for
1973 averaged 84%. With the expansion
now under construction, effluent quality
should improve and the facilities should
have adequate capacity to meet projected
needs through the early 1990's. A detailed
description of the effluent characteristics
is contained in Table 4 . Portions of the
effluent are used for cooling water for
the Nevada Power Company's Clark Gene-
rating Station and for irrigation. The re-
System Administration
The Board of Trustees for the Sanitation
District establishes policy. The Board
of Trustees consists of the seven members
of the Board of County Commissioners for
Clark County, Nevada. The Sanitation
District staff is divided into four depart-
ments (1) administration, (2) general
offices, (3) waste-water collection system
operations and (4) waste-water treatment
plant operations. The plant is manned
round -the-clock.
City of Henderson
The City of Henderson operates a waste-
water collection system and two waste -
water treatment plants. These facilities
provide service to virtually all of the
people residing in Henderson.
Collection System
The City of Henderson's waste-water col-
lection system is intermingled with small
portions of the BMI system from which
it originated. All the waste water collected
south of the BMI plant and northeast of
the Boulder Highway, plus that carried
in the Center Street trunk, is diverted to
the Henderson waste-water plant No. 2
purchased in 1973 from BMI. The re-
maining waste-water flows are treated
136
-------
VARIATIONS
WASTE WATER FLOW
LAS VEGAS VALLEY
TYPICAL MONTHLY VARIATIONS IN WASTEWATER FLOW ©
MONTH JAN FEB MAR APR MAY
>VERAS?MONTH 9M 9« 95° 965 "°
JUN
102.8
JUL AUG
107.2 108.0
SEP OCT
104.1 100.9
NOV DEC
99.9 99.6
TYPICAL HOURLY WASTEWATER FLOWS ©
HOURCA.M.) 12345
AVERAGE HOUR l00'9 m 78'9 ™ 637
HOUR(RM.) 12345
%
WERAGE HOUR I3°'3 '292 123>4 "8° ll4'9
6
60.2
6
113.9
7 8
61.4 67.9
7 8
114.4 115.8
9 10
76.9 89.1
9 10
116.9 116.1
II 12
104.2 121.2
II 12
113.4 108.7
DAILY AND PEAK HOUR FLOW FACTORS ©
I
Y
w
V
p
c
0
u
N
T
Y
W
W
P
YEAR
1969
1970
1971
1969
1970
1971
AVERAGE DAILY
FLOW-mgd
22.5
24.5
25.4
10.1
10.6
12.5
MAXIMUM DAY
FLOW-mg
29.5
32.0
29.1
13.0
13.6
14.9
Ratio to Average Day
1.31
1.31
1.15
1.29
1.28
1.19
PEAK HOUR
RATE-mgd
37.0
38.0
37.5
16.0
17.0
19.5
Ratio to Average Day
1.64
1.55
1.50
1.58
1.60
1.56
totioto Maximum Day
1.25
1.19
1.29
1.23
1.25
1.31
RECOMMENDED FACTORS FOR DESIGN
I960 ^xxxxxxxxxx^xxxxxxxxxx | 35
1990 [xxxxxxxxxxxl
'XXXXXXXXXX!
1.30
1.25
xxxxxxxxxxx
xxxxxxxxxxx
1.75
1.65
1.55
1.35
1.30
1.25
SOURCES**® A Comprehensive Water Quality Control Program for the Lot Vega* Drainage
Bosh-Phase II, December 1969 by Boyle Engineering and CHgM.
(?) Design Appendix to the November Project Report- Los Vegas Wash Pollution
Abatement Project, November I, 1972 by NECON.
table 21
-------
DOMESTIC AND COMMERCIAL
MAXIMUM DAY WASTEWATER FLOWS
PRESENT AND PROJECTIONS
YEAR
PRESENTQ
1973
PROJECTIONS®
1980
Population Level
Minimum
Medium
Maximum
1990
Population Level
Minimum
Medium
Maximum
2000
Population Level
Minimum
Medium
Maximum
LAS VE6AS
VALLEY
(mgd)
51.3
81.9
85.2
90.4
106.2
1 13.4
124.3
129.7
137.5
157.2
WASTEWATER FLOW COMPONENTS OF LAS VEGAS VALLEY
LAS VEGAS
(mgd)
24.4
43.8
44.8
47.8
56.4
60.6
65.8
61.8
66.3
75.4
UNINCORPORATED
AREA
(mgd)
20.2
27.3
28.7
30.1
35.2
36.9
40.3
51.3
53.3
58.0
NORTH
LAS VEGAS
(mgd)
4.7
8.1
8.7
9.1
11.3
12.2
13.7
12.9
13.7
16.6
HENDERSON
(mgd)
2.0
2.7
3.0
3.4
3.3
3.7
4.5
3.7
4.2
7.2
SOURCES:(T) Based on 1973 Wattewoter Plant Records for CCSD and CLV amd Estimates for Henderson Plants.
CIV WWTP Flows have been prorated between the Cities of Las Vegas and North Las Vegas.
(?) Based on Average Wastewater Flows shown on TABLE t\ multiplied by Recommended
Factors for Design shown on TABLE 20
table 22
-------
at the Henderson No. 1 city-built treat-
ment plant. Records on the portion of
total flows treated at each plant and the
basis for proportioning are not available.
The waste-water system also collects the
waste water of the East Las Vegas area
and portions of the City located northerly
of BMI. Prior to anticipated future de-
velopment, interceptor trunk and main
collection lines will need to be extended
into presently undeveloped areas. The
existing service area and the interceptor
system together with proposed system
expansions are shown on Figure 27'.
Treatment Facilities
Henderson treatment plant No. 1 is of the
Imhoff tank-oxidation pond type. Plant
No. 1 was designed for an average daily
flow of 1. 5 mgd. Present daily flow rates
are estimated to be about 0. 7 mgd to 0. 9
mgd. Effluent from the plant is piped to
unlined holding ponds, from which the
effluent is disposed of by evaporation and
seepage to the near-surface ground-water
zone. The treatment effectiveness is
difficult to evaluate because of the diffuse
nature of the seepage portion of the dis-
posal system. Influent and effluent are
not routinely sampled, and no definitive
past records are available. The limited
available data is shown in Table 5.
a portion of central Henderson and the
small residential area west of the
Henderson High School are all tributary
to plant No. 2. Plant No. 2 is a two-
stage trickling filter plant designed to
provide treatment of domestic •waste
water from the BMI complex. Certain
industrial wastes, characterized by a
very low pH, occasionally are received
at the plant and have pronounced detri-
mental effects on plant operation. Flow
measurement equipment at Plant No. 2
is reported to be inoperative. Estimates
of flow reaching the filter are 0.9 to 1. 1
mgd, which is about the original design
capacity of this plant.
Both plants No. 1 and No. 2 discharge
their sanitary and industrial effluents
into unlined ponds constructed of native
material. The native soil is at least
semi-permeable, and infiltration into the
ground from these ponds is known to
occur. Such treatment as occurs may be
classified as similar in nature to that
from a combination waste stabilization
pond and infiltration gallery. The in-
filtration of large quantities of basically
untreated industrial waste and lesser
amounts of domestic waste water into the
near surface ground-water zone has
had a detrimental effect upon quality of
ground water entering the Las Vegas
Wash.
The remaining portion of the City is served
by Henderson's treatment plant No. 2.
The BMI industrial complex sanitary
sewerage system, that portion of Hender-
son lying east of the Boulder Highway,
Since accurate measurements of surface
and subsurface flow from the BMI and
Henderson pond systems are not avail-
able, it is not possible to accurately
characterize these discharges to Las
139
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Vegas Wash. It seems probable that
waste waters which percolate through
the pond bottoms are the worse for their
passage through the surrounding soil,
at least from a TDS standpoint. A pre-
vious study indicates the probability
that, while high TDS water may enter
the Wash from the BMI ponds, these
ponds do not contribute any significant
pollution in terms of phosphorus or
uncombined nitrogen.
The limited data available indicates that
Henderson's waste-water plants are
probably not producing a good quality
secondary effluent. If Henderson is
to grow and prosper in a healthy climate,
waste-water treatment facilities must be
upgraded and expanded. Currently, the
city of Henderson is considering a pro-
posal to modify its existing means of
treatment. The proposal is for develo-
ping four separate secondary treatment
facilities which provide a trickling filter
plant with evaporation ponds for the
Henderson Core area, two trickling
filter plants with irrigation for the Green
Valley area and a trickling filter plant with
lime addition for phosphorus removal for
the Lake Adair area.
Systems Administration
The city of Henderson Department of
Public Works is responsible for the ad-
ministration, maintenance and operation
of the City's waste-water collection and
treatment facilities. The plants are nor-
mally staffed seven days a week during
an eight hour work day and as needed in
case of emergency.
Variation in Waste Flows
Variations in waste-water flow rates
have been studied utilizing the records
of the City of Las Vegas and Clark
County waste-water treatment plants.
These variations are shown on Table 21
together with recommended factors for
design. The recommended design factors
have been applied to the average day flows
shown on Table 20 to derive the projected
maximum day waste-water flows shown on
Table 22.
It should be noted that the maximum day
flow occurs during the summer months
and is a result of the influx of tourists
into the Las Vegas Valley. Furthermore,
flows equal to or approaching the maximum
day flow occur for several weeks at a time
during the summer months. This is also
the period of time when Las Vegas Bay is
most susceptible to algal growth, thus,
the maximum day flow becomes the con-
trolling flow for the design of waste-
water treatment facilities.
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Ten possible alternatives have been con-
sidered for implementation to meet the
water resource management goals and
water quality objectives.
Of the alternatives to be discussed 4
of the alternatives have discharges into
the receiving water as their method of
disposal. These alternatives are: Al-
ternatives 2-Complete Treatment; 3-
Advance Waste Water Treatment and
Return to Lake Mead; 7-Combination
Alternative Export to Dry Lake and
1*0-Amended Combination Alternative.
The advantages of discharging into the
Las Vegas Wash are that the greenbelt
will be maintained and effluent returned
to Lake Mead and to the Colorado River
could be credited up to the amount of
Colorado River water allocated to Ne-
vada.
Another method of discharge investigated
in the alternatives is export with land dis-
posal. Alternatives 4-Dry Lake Export;
5-Export to Eldorado Valley; 6-Export
to Hidden Bailey-Jean Lake Area and
7-Combination Alternative-Export to
Dry Lake all use this method. Other
methods of discharges were Alternative
1-Groundwater Recharge and Alternative
8-Deep Well Disposal.
DESCRIPTION OF ALTERNATIVES
Alternative 1 - Ground Water Recharge
(subsurface disposal)
Waste water at the central collection
point will be given complete waste water
treatment for the purpose of improving
the physical, biological, chemical and
biochemical characteristics sufficiently
to preclude degradation of the existing
ground water supply. The majority of
the effluent from the complete treatment
plant would be injected into the valley's
water-bearing aquifers through a net-
work of injection wells. The water could
be retrieved through a system of wells
for delivery to the portable water system.
Effluent from the advanced waste-water
treatment plant phase of the process would
be used for in-valley irrigation and main-
tenance of a greenbelt in Las Vegas Wash.
Brine waste resulting from the desalina-
tion process would be exported out of
the Las Vegas Valley for disposal by
H
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evaporation.
To meet the existing ground water quality
condition, a reduction in concentration of
total dissolved solids (.TDS), phosphorus,
nitrogen, biochemical oxygen demand
(BOD), chemical oxygen demand (COD)
and suspended solids would be required
and bacteria and viruses should be eli-
minated. If these constituents are re-
duced in concentration sufficient to pre-
clude degradation of ground water quality,
the effluent from the plant would exceed
water quality standards that have been
established for the Las Vegas Wash.
Unfortunately, present knowledge of the
physical hydraulic, or water quality
characteristics of the ground water basin
beneath Las Vegas Valley is insufficient
to assure the viability of this alternative.
Before major financial commitments are
made for a recharge program, it will be
necessary to first define the physical
characteristics of the basin through a
program of exploration, data collection,
and data analysis. It would then be ne-
cessary to demonstrate the feasibility
of ground water recharge utilizing a
pilot operation through the physical
chemical and biological practicability
as well as financial feasibility of such
a program.
Due to the large number of technical
unknowns which exist for this alternative
with regard to the degree of pretreatment
and with regard to the ground water basin,
this alternative does not provide a readily
implementable solution to the existing pol-
lution problems. Further, lack of sufficient
design data precludes the possibility of a
meaningful cost-effective analysis. This
alternative is not presently considered
viable and is eliminated from further eva-
luation.
Alternative 2 - Complete Treatment
(receiving water discharge and direct
reuse)
Waste water, at a central collection point,
will be given AWT and desalination for the
purpose of improving physical, biological,
chemical and biochemical characteristics
sufficiently to meet U.S. Department of
Public Health drinking water standards.
Effluent from the plant could be used for
(1) agricultural irrigation, (2) a pilot
ground water recharge program, (3) dis-
charge to Las Vegas Bay or Lake Mead
for return flow credit and (4) blending
with the domestic water supply for direct
reuses.
Complete treatment, including the re-
duction in concentration of nitrogen,
phosphorus, TDS, BODs, COD and SS, with
disinfection, will produce an effluent which
will meet and exceed the water quality
standard for Las Vegas Wash. The ef-
fluent from this process should be usable
for any water demand in the Las Vegas
Valley. This alternative has the dis-
advantage of high-unit processing cost
due to the high energy consumption of
the desalination facility and has some
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technical problems in as much as faci-
lities of the size required have not yet
been constructed. Furthermore, the con-
trol of bacteria and viruses in a direct
reuse application is not known to have
been demonstrated to the satisfaction of
the nation's health authorities. Future
technical advances to make complete
treatment more feasible. Complete
treatment is considered to be one of the
more viable and desirable alternatives.
Alternative 3 - Advance Waste Water
Treatment and Return to Lake Mead
(receiving water disposal)
Alternative 3 provides for waste water
collection at a central point, provision
of AWT to improve physical, biological,
chemical and biochemical characteristics
to a level that will meet the existing water
quality standards for discharge to the
wash.
The AWT plant would be designed to re-
duce the concentration of phosphorus SS,
BOD5 and COD. The water will be disin-
fected prior to discharge. The effluent
from this plant would meet the water
quality standards now set for Las Vegas
Wash, but may complicate meeting the
proposed one million pounds TDS Load
recommended by EPA.
The advantage of returning adequately
treated waste water to Lake Mead is that
effluent returns to the Colorado River
which may subsequently be beneficially
reused downstream.
The technical feasibility of the proposed
AWT plant and the beneficial usage of the
effluent for In-Valley irrigation; mainte-
nance of a green belt in the Las Vegas Wash
and as credit for allocated Colorado River
withdrawals makes this alternative viable.
Alternative 4 - Dry Lake Export (land
disposal)
Secondary treated waste water, collected
at a central point, would be exported by
pipeline to Dry Lake Valley for disposal
by evaporation. In the time period of
1990 to 2000, depending upon population
growth and water usage, AWT and desali-
nation of required waste water quantities
to meet potable usage would be initiated.
Brine wastes from the desalination pro-
cess would be exported to Dry Lake Val-
ley for disposal by evaporation. In the
same pipeline originally constructed for
the export of waste, waste water of good
quality exported to Dry Lake Valley would
be segregated through the use of a flood
control principle of waste water of poorer
quality. At Dry Lake Valley, a portion of
'the good quality waste water could be
diverted for use by the proposed Allen
Power Project, and, if proven feasible,
portions of the waste water could be used
for irrigation in the Dry Lake Valley.
This alternative does not provide for main-
tenance of a green belt area in Las Vegas
Wash. This alternative has been elimina-
ted as a viable alternative because it does
not meet the basic project objective of pre
serving the Las Vegas Wash environment.
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Alternative 5 - Export toJSldorado Valley
(land disposal)
Waste water, collected at a central collec-
tion point, would be pumped and trans-
ported by pipelines to Eldorado Valley
for disposal by evaporation. A portion
of the waste water exported to Eldorado
Valley would be used for irrigation of
agricultural land. A small portion of
the waste water at the central collection
point would be given AWT. The effluent
of the AWT plant would be used for a pilot
desalination plant, pilot ground water re-
charge program and for In-Valley irriga-
tion.
Waste water treatment plant effluent, be
it secondary or AWT effluent or a blend,
would be available for the maintenance
of a green belt in the Las Vegas Wash.
The waste water to be exported to El-
dorado Valley would not receive AWT.
The pilot scale AWT near the Las Vegas
Wash would be designed to reduce the
concentration of phophorus, BODs , SS,
and COD. Effluent would be disinfected
to produce a water that would preclude
degradation of the existing ground water
supply beneath the valley.
Investigation into the surface soils and
shallow geology of the Eldorado Valley
indicates that it may not be possible to
avoid pollution of the regional ground
waters without extensive evaporation
pond lining. Also, there would not be
any provision in the Eldorado export
alternative for diverting water to the
Allen Power Project for beneficial
reuse. Due to the similarity of the
Eldorado export alternative and the
Dry Lake export alternative except for
additional costs of the evaporation pond
lining and a loss of a possible beneficial
reuse of the waste water as power plant
cooling water, the Eldorado export al-
ternative has been eliminated as a viable
alternative.
Alternative 6 - Export to Hidden Valley -
Jean Lake Area (land disposal)
Waste water collected at a central collec-
tion point would be pumped and transported
by pipeline to the Hidden Valley-Jean Lake
Area for disposal by evaporation. All
elements of this program are similar to
those outlined by the Eldorado Valley al-
ternative including the loss of a possible
beneficial waste water reuse and a neces-
sity of lining the evaporation pond. For
these reasons the export to Hidden Valley-
Jean Lake area has been eliminated as a
viable alternative.
Alternative 7 - Combination Alternative -
Dry Lake Export (receiving water dis-
charge, reuse, land and subsurface
disposal)
Waste water, collected at a central col-
lection point, would be pumped and trans-
ported by pipeline to Dry Lake Valley
for disposal by evaporation. At Dry Lake
Valley, portions of the waste water would
be diverted for use by the proposed Allen
Power Project. If proven feasible, por-
tions of the waste water could be used for
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limited agricultural irrigation at the Dry
Lake disposal site. About one (1) mgd
of the waste water at the essential col-
lection point would be given AWT. The
effluent of the AWT plant would be used
for a pilot desalination plant and pilot
ground water recharge program. Effluent
would be avilable for the maintenance of
the green belt in the Las Vegas Wash.
The waste water could be exported to
Dry Lake Valley and would not receive
AWT. The pilot scale AWT plant would
be designed to produce the concentration
of phosphorus, BODc,, SS, and COD.
Effluent would then be disinfected to pro-
duce a water that would preclude degrada-
tion of the existing ground water supply.
effluent to be discharged to the Las
Vegas Wash would receive additional
treatment as necessary to meet the
water quality standards set for the
Las Vegas Wash. The AWT plant
would be designed for removal of SS
and biologically active compound in
the waste water that would foster the
growth of biological slimes. The
removal of these constituents is essen-
tial to prevent flooding of the receiving
aquifers serving as the ultimate disposal
sites of the waste water. AWT effluent
used to maintain a green belt in Las
Vegas Wash would be treated to the
level necessary to meet water quality
standards for the Wash.
The possible beneficial uses of the waste
water in the vicinity of the Dry Lake
Valley, abatement of pollution, and
maintenance of a green belt in the Las
Vegas Wash make this alternative viable.
Alternative No. 8 - Deep Well Disposal
(subsurface disposal)
Waste water, from a central collection
point, would receive AWT to remove SS
and biologically active components to
preclude the possibility of plugging the
injection well and surrounding aquifers.
The majority of the effluent from this
plant would be injected into confined
aquifers through a network of deep wells
for ultimate disposal. The remainder
of the effluent from the AWT plant will
be available for the maintenance of a
green belt in the Las Vegas Wash. The
There is insufficient data available at
the present time about the geological and
hydraulic characteristics of the aquifers
underlying the Las Vegas Valley. With-
out this information it is not practical
to evaluate the feasibility of deep well
disposal of large quantities of waste
water. Before a program of disposal
by deep well injection could be imple-
mented, a program of exploration, data
collection and analysis would have to be
undertaken to determine if a confined
aquifer exists that could be used for the
ultimate disposal of the waste water.
Another geological consideration that
would have to be analyzed would be the
effect of seismic activity caused by deep
well injection.
Due to the time and expense that would
be required to determine these geological
characteristics of the basin underlying the
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Las Vegas Valley and the potential for pol-
luting the potable water aquifers through
possible aquifer inter-connection, this
alternative is not considered to be viable
for implementation.
Alternative 9 - No Action
The no action alternative will permit exis-
ting methods of waste water treatment and
disposal to continue. No improvements
or upgrading of treatment processes would
be made to improve the water quality of
the Las Vegas Wash.
This alternative is not being considered
as being viable. It violates EPA's and
Nevada's water quality standards for Las
Vegas Wash and results in the continued
pollution of Las Vegas Bay and Lake
Mead.
Alternative 10 - Amended Combination
Alternative (receiving water discharge,
reuse, land and subsurface disposal)
Waste water, at a central collection
point, would be given AWT for the pur-
pose of removing physical, biological,
chemical and biochemical constituents
to meet water quality standards. Efflu-
ent from this plant would be available
for such beneficial reuses as: (1) cool-
ing water for the proposed Allen Power
Project, (2) an In-Valley irrigation pro-
gram, (3) as a water source for a pilot
desalination plant, (4) as a water source
for a pilot ground water recharge pro-
gram, (5) maintenance of a green belt
in Las Vegas Wash and (6) as a water
supply for return flow credit from the
Colorado River when returned to Lake
Mead. This alternative is the same as
Alternative No. 3, AWT and return to
Lake Mead, with the addition of the
above-mentioned reuse programs, and
reduced volumes of water being dis-
charged to Las Vegas Wash.
The plant would be designed to reduce
the concentration of phosphorus SS,
BOD5, and COD. Effluent would then
be disinfected. Plant dischargers would
meet water quality standards and effluent
limitations set for Las Vegas Wash. The
advantages of having effluent available
for use by the Allen Power Project faci-
lity is that the water used by the facility
would be purchased by the Nevada Power
Company, thus becoming a source of
revenue for the community. Also, the
technological feasibility of the proposed
AWT plant and the beneficial uses of the
effluent for In-Valley irrigation, main-
tenance of a green belt in Las Vegas
Wash, the potential for an additional
potable water supply and a pos sible
credit against withdrawals from the
Colorado River make this alternative
viable.
SCREENING OF ALTERNATIVES
All the treatment alternatives were eval-
uated using eight qualitative parameters.
They were presented in the facilities plan
Annex A, and we concur with their deter-
mination. The evaluations of the alterna-
tives are listed in Table 23 in matrix
form with the relative variance of each
alternative listed. The numerical values
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of 1, 2 and 3, representing, yes, question-
able, and no, respectively, are assigned
to determine the relative adequacy or
inadequacy of each individual alternative
to each parameter. The overall relative
merit of each alternative is then deter-
mined by totaling each vertical column.
The lowest total is representative of the
alternative with the highest overall merit
and the highest total is representative of
the alternative with the lowest overall
merit.
Reviewing the individual qualitative des-
cription of each alternative and determina-
tion of the overall relative merits of each
alternative using the matrix indicates that
the following four (4) alternatives are
most viable.
Alternative No. 2 - Complete Treatment
Alternative No. 2 - Complete Treatment
The Complete Treatment Alternative is
designed to collect and treat secondary
effluent from the existing Clark County
waste-water treatment plant, the exist-
ing City of Las Vegas waste-water treat-
ment plant- and the existing City of Hen-
derson waste-water treatment plants.
The treatment process would produce
a water which should exceed discharge
requirements for Las Vegas Wash. Be-
cause of the high quality of the effluent
produced by this alternative, it is
planned that it would be blended with
Lake Mead water just ahead of the water
treatment plant of the Southern Nevada
Water Project (SNWP). Thus, the pri-
mary objective of the Complete Treat-
ment Alternative is indirect reuse of
reclaimed waste water for potable
purposes.
Alternative No. 3 - Advanced Waste
Water Treatment and Return to Lake
Mead
Alternative No.
Alternative
7 - Combination
Alternative No. 10 - Amended
Combination Alternative.
These four alternatives will be analyzed
in more detail.
This alternative involves construction of
a complete waste-water reclamation plant
utilizing phosphorus removal by chemical
coagulation, ammonia stripping and fil-
tration. Carbon absorption and desalina-
tion would be applied to a portion of the
total flow. The desalinated water would
be blended with the remainder of the
flow from the AWT plant. The blended
effluent would be disinfected with chlorine
and aerated. An export pipe would be
required with this alternative for disposal
of brine generated in the desalination
process. The high quality of this effluent
would economically preclude discharge
into Las Vegas Wash where it could
be contaminated by high salinity ground-
166
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PRELIMINARY
SCREENING OF ALTERNATIVES
ALTERNATIVE NO.
Meets Federal and State Standards
Provides .Immediate Pollution Abatement
Technically Feasible Today
Protects Water Resource
Augments Water Resource
Enhances Water Quality
Potential for Agriculture
Environmental Enhancement
TOTAL
ORDER OF PREFERENCE
j ^"/ ^ / x1 / ••
-------
water discharges. The benefits of desali-
nation could be lost by adding the treated
water to the water in Las Vegas Wash
which has a high level of TDS. Therefore,
conveyance of the plant effluent to the
SNWP would be via lined canal and pipe-
lines.
Special provisions for maintaining the Wash
will be required with this alternative. This
will basically consist of diverting a small
flow of water to sustain vegetation and wild-
life. This water will be diverted prior to
desalination and may be blended with
secondary treatment plant effluent in
order to provide nutrients necessary to
sustain vegetation along the Wash.
This alternative provides an immediate
solution to the problem of the discharge
of pollutants (including TDS) to Las
Vegas Bay. In addition to water recla-
mation for indirect potable reuse, this
alternative also includes an in-valley ir-
rigation system.
The Complete Treatment Alternative will
meet the recommended water quality ob-
jectives developed for potable water sup-
ply, that is, U.S. Public Health Service
Drinking Water Standards. The process
as described will incorporate sophisticated
unit processes, however, there are some
questions regarding the technical feasi-
bility of operating a desalination process
on the large scale necessary to meet the
requirements of this project.
This alternative would not degrade water
quality in Las Vegas Wash. While most
of the reclaimed water from this treat-
ment plant would be diverted to the existing
SNWP for reuse, some of the water would
be diverted, prior to the desalination pro-
cess, for reuse in the in-valley irrigation
system and for a Las Vegas Wash main-
tenance program. Brine wastes would be
exported out of the Valley.
There is no Federal effluent requirement
and no National Pollution Discharge Eli-
mination System (NPDES) permit at the
present time for this proposed system.
Preliminary discussions have indicated
that an effluent quality equal to or better
than the water quality standards for Las
Vegas Wash would be acceptable.
This alternative meets the criteria for
a Best Practicable Waste Treatment Tech-
nology (BPWTT) treatment and reuse
alternative.
Alternative No. 3 (Modified) -
Advanced Waste-water Treatment
and Return to Lake Mead
The AWT and Return to Lake Mead
Alternative is designed to collect and
treat secondary effluent from the ex-
isting Clark County waste-water treat-
ment plant, the existing City of Las
Vegas waste-water treatment plant and
the existing City of Henderson waste-
water treatment plants. The treatment
process employed is designed to produce
an effluent which will meet anticipated
168
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effluent discharge limitations. The
primary objective of this alternative
is to treat the waste water and discharge
it to the receiving water. As in all plans,
a portion of effluent from this system
would be utilized for future in-valley ir-
rigation. In addition, this alternative
would maintain vegetation in Las Vegas
Wash.
This plan includes initial construction of
an AWT plant to provide reduction in
BOD5, SS and COD levels by post aeration
prior to discharge to Las Vegas Wash.
This alternative does not presently include
any experimental pilot programs to deter-
mine feasibility of more sophisticated
processes that might be required to meet
future water quality standards.
A comparison of the effluent characte-
ristic for AWT and Return to Lake Mead
with the water quality standards for Las
Vegas Wash indicates that the water quality
standards for the Wash would be met ex-
cepting the proposed salt load criterion.
There are no Federal effluent require-
ments and no NPDES permit at the present
time for this proposed plan. Preliminary
discussions have indicated that an effluent
quality equal to the water quality standards
for Las Vegas Wash would not be possible,
if the proposed salt load criterion is en-
forced.
This alternative meets the BPWTT re-
quirements for a waste treatment and
discharge alternative.
Alternative Number 7 - Combination
Alternative
The Combination Alternative provides an
immediate solution to the problem of the
discharge of pollutants (including TDS)
to Las Vegas Bay and also provides a
facility which would make secondary ef-
fluent available to the Allen Power Pro-
ject station for power cooling water. It
provides a pipeline for conveying future
brines from desalination installations
when such installations are required.
A future in-valley irrigation systen would
be structured to deliver secondary effluent
for beneficial reuse within the Valley.
This irrigation system can be expanded
and extended as the demands develop.
The pilot programs involving AWT and de-
salination are included to provide the
information necessary to determine the
economics and quality of water required
for proposed programs of desalination,
ground-water recharge, and potable water
use. The program of ground-water basin
definition and pilot recharge operation
will offer the opportunity to define and
hopefully make use of the ground-water
basin for the storing of reclaimed waste
water. The ground-water basin will be
evaluated as a vehicle for water distri-
bution within the valley and for water
"banking" against future needs. The
element of the system provides for the
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maintenance of Las Vegas Wash and
the export of saline ground waters now
entering the Colorado River system via
Las Vegas Wash. Thus, the program
will meet the objectives desired of the
pollution abatement program.
The export system includes: (1) col-
lection facilities to carry waste waters
from secondary treatment plants, (2)
collection and conveyance of industrial
waste discharges and intercepted flows
from the Las Vegas Wash to flow re-
gulating reservoirs, (3) compartmen-
talized reservoirs for high and low
quality waste waters and (4) an ex-
port pipeline with pumping stations in-
cluding surge protection and forebays.
Flows will be conveyed to a disposal
area in Dry Lake Valley which includes
irrigation and the utilization of the main
playa of Dry Lake to evaporate the waste
water not uspd for other purposes.
In addition to the main export system,
this alternative also proposes several
subsystems; (1) future in-valley ir-
rigation system, (2) pilot plant develop-
ment, (3) pilot desalination and recharge
facilities and (4) Las Vegas Wash main-
tenance. These subsystems, except
the Wash maintenance subsystem, are
identical to the subsystems proposed in
Alternative Number 10.
the Wash. This.is desired because of
the great concern and high value placed
on the Wash by a substantial segment of
the local community.
Recent investigations have indicated that
for Wash maintenance, nutrient bearing
waste-water flows to the Wash should
vary from 3 mgd in the winter to 19 mgd
in the summer. This water would flow
down the Wash and then would be collec-
ted at a natural barrier in the Wash and
pumped back to the collection system to
be exported with the other waste water
to Dry Lake'Valley. This program would
permit retention of the majority of the
Wash in its present vegetative state,
collect and dispose of undesirable poor
quality ground waters and result in the
substantial elimination of TDS and nut-
rient pollution in Las Vegas Bay.
Export to Dry Lake Valley will meet the
proposed water quality standards by diver-
ting the combined waste-water flow to
Dry Lake Valley, thus, eliminating all
discharges of pollutants to Lake Mead.
The diversion system, as previously de-
scribed, would export waste water out
of the Las Vegas Valley for ultimate
disposal by evaporation. The effluents
from the existing secondary plants would
not require any further treatment prior
to exportation.
The Las Vegas Wash maintenance program
proposes the release of secondary treated
waste water in controlled amounts so as
to maintain a permanent greenbelt in
There are no Federal effluent require-
ments and no NPDES permit requirements
if there is no discharge to the surface
waters of the State. Since this alternative
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proposes to export the flow, there will be
no discharge to the surface waters other
than that for the Wash maintenance pro-
gram. The water which is discharged
to the Wash will be pumped out of the Wash
before reaching the North Shore Road sam-
pling point. Thus, this alternative will
meet proposed water quality for Las Vegas
Wash and probably would not meet "effluent
limitations. "
Effluent limitations have not been es-
tablished as of this writing. However,
preliminary discussions have indicated
that an effluent quality equal to the water
quality standards for Las Vegas Wash (as
measured at North Shore Road) should be
assumed. This alternative meets the
BPWTT requirements for a land application
alternative. Effluent exported to the Dry
Lake Valley will not degrade either sur-
face or ground-water resources. The
ground water below Dry Lake is protected
from the waste water by the impervious
geologic formations within the Dry Lake
Basin.
water, (2) in-valley irrigation, (3) pilot
scale desalination plant, (4) pilot scale
ground-water recharge program and (5)
receiving water discharge for return flow
credit.
AWT processes would include lime coagu-
lation, single stage recarbonation, fil-
tration, chlorination of effluent for dis-
infection, and post aeration. The plan
includes lime reclamation facilities to
minimize chemical requirements for lime
coagulation, minimize the amount of re-
ject solids to be disposed of and to supply
needed carbon dioxide for recarbonation.
The Nevada Power Company presently uses
lime coagulated secondary effluent water
for cooling purposes. Present reuse of
treated effluent by the Power Company
occurs at its Clark Station and Sunrise
Station. This alternative anticipates
that AWT effluent will be purchased by
Nevada Power Company for use at the
proposed Allen Power Project near Dry
Lake.
Alternative Number 10 - Amended
Combination Alternative
The Amended Combination Alternative is
designed to collect, treat, and reclaim
waste water from the existing Clark Count,
City of Las Vegas, and Henderson waste -
water treatment plants. The objectives
of this alternative include a high degree
of treatment and several reuse systems.
Reuse systems include: (1) industrial
reuse, primarily as power plant cooling
The utilization of AWT effluent for ir-
rigation of agricultural lands, landscaping
of parks and public facilities, golf courses
and greenbelt areas within Las Vegas
Valley offers an opportunity for the bene-
ficial reuse of these highly treated waste
waters.
Operation of an in-valley irrigation system
utilizing AWT effluent would have all the
benefits of the irrigation system proposed
in the export alternative. It would also
171
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provide additional benefits due to the
higher quality of the water. The health
hazards associated with irrigation using
secondary effluent would be substantially
reduced; in fact, use of AWT effluent should
not impose any undue risks to health be-
cause of the high level of treatment and
reliability that exists with this process.
Secondary effluent is presently used at
two Las Vegas golf courses for irrigation.
This practice has resulted in both odor
problems and soil plugging. It is anti-
cipated that effluent from the AWT plant
would significantly reduce these problems.
Further, because of the high quality of
this effluent, it is anticipated that it can
also be used for additional park and green-
belt areas.
of high quality reclaimed waste water.
This will provide sufficient capacity for the
proposed ground-water pilot recharge pro-
gram.
A pilot ground-water recharge program
is also proposed as an integral part of
this alternative. This program is pro-
posed to accomplish the following objec-
tives:
Determine the feasibility of
recharging high quality reclaimed
waste water into the Valley's ground -
water formations.
Formulate recharge methods of
injecting effluent water for future
use as a supplemental water supply
A pilot desalination program is proposed
in conjunction with this alternative to
accomplish the following objectives:
Determine the feasibility of
desalting AWT effluent
Evaluate specific desalination pre-
treatment requirements
Evaluate operation techniques
Investigate health hazards
Investigate environmental impacts
of a desalination operation
This plant would produce about 1.0 mgd
Determine water quality require-
ments for recharging water.
The balance of the water will be discharged
to Las Vegas Wash. This flow would main-
tain a permanent greenbelt along the Wash;
however, there is some question as to the
ability of the AWT effluent to supply suf-
ficient nutrients to support present vege-
tation.
There is no NPDES permit at the present
time for the proposed discharge and there
are no official effluent limitations; how-
ever, an effluent quality equal to the water
quality standards for Las Vegas Wash
would be acceptable.
172
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This alternative meets the BPWTT re-
quirements for treatment and reuse of
waste water. In this alternative,
heavy emphasis has been placed on re-
clamation and multiple beneficial re-
use of the waste-water resource.
ENERGY CONSUMPTION OF THE VIABLE
ALTERNATIVES
When the total power required by the
different alternatives is compared to
the total power available in the Las
Vegas Valley, it may be seen that the
highest maximum day demand is only
about 1% or less of available genera-
ting capacity. Thus, the impact of any
one of the four most viable alternatives
on the Las Vegas Valley power supply
is small.
The four most viable alternatives each
consume significant amounts of energy.
Electric power would be purchased from
Nevada Power Company. The estimated
energy required for each alternative is
shown in Table 24. Electrical power
would be purchased monthly at an April
1974 cost of 1.033£ per kwh, plus a.
monthly demand charge of $1.75 per
kw. It is probable that the price of elec-
trical power will increase significantly
during the life of this project. Alter-
natives 2 and 7 will be subject to larger
changes in total yearly costs as the power
rate increases when compared with Al-
ternatives 3 and 10.
The analysis uses maximum day running
horsepower as a basis of comparison.
This is the amount of power that would
be used when process flow is equal to
the maximum day flow.
Existing and projected power generation
capacity available to Las Vegas Valley
is summarized in Table 25.
Fuel sources that would be used in the
alternatives are natural gas and fuel oil.
Despite the anticipated shortage of these
two items, local suppliers have indicated
that adequate supplies should be available
in the future.
RELATED CONSTRUCTION
Allen Power Project
The Nevada Power Company has proposed
the construction of a coal-fired steam elec
trical generating plant to be located in the
Arrow Canyon Mountains, twenty miles
northeast of Las Vegas. The plant would
ultimately generate 2000 megawatts of
power, and is estimated to cost
$600,000,000.
It is presently proposed that the project
would be constructed in four equal stages:
500 megawatts becoming operational in
each year for 1979, 1980, 1981, and 1982.
Power would be sold to Southern California
173
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Edison Company (SCE) to supply the Los
Angeles area: 70% of the total from 1979
to 1983, 50% of the total from 1984 to
1990, and then cutting off all sales to SCE
by 1994. The remaining 30% would be con-
sumed in the Las Vegas area, and be in-
creased in proportion to the decreases
noted above. This arrangement would
allow the total capacity of the Allen Power
Project to ultimately be recaptured and
used in Southern Nevada.
When in full operation, the plant would
burn about 16, 000 tons of coal each day,
using oxygen from the air in the combus-
tion process, and producing carbon di-
oxide, water vapor, 34. 5 tons of sulfur
dioxide (SOz), 14.4 tons of particulate
matter, and other gaseous by-products
each day. It would also produce heat
necessary to drive steam turbines and
turn the generators which produce the
electricity.
Cooling water would be required to re-
move waste heat energy by condensing
steam used in the boilers and turbines.
This cooling water would be used over
and over again by having its waste heat
removed to the atmosphere through eva-
poration. Large cooling towers are
usually constructed for this purpose,
with the water cascading down a series
of short drops to allow maximum ex-
posure to the air. Fresh water is added
as evaporation occurs, but eventually
the salts become so concentrated in this
water that they begin to precipitate (come
out of solution), coating the cooling tower
surfaces, a problem called "scaling".
To prevent this from occurring, water
(called "blowdown", and comprising only
about 20% of the volume flowing into
the towers) must be removed and re-
placed with fresh water. Nevada Power
Company representatives state that they
would use part of the blowdown water to
"scrub" the gases from the combustion
of the coal, removing particulate matter,
and then either evaporate the water in
sealed ponds or reclaim it by a de-
salinization process. High quality pro-
duct water would then be used as boiler
water, with the brine being evaporated
at the site. Estimates of make-up
cooling water requirements are as
follows:
RECLAIMED WASTEWATER DELIVERIES
ALLEN POWER PROJECT
Peak
Demand
(MGD)
12
24
36
48
Average
Demand
(MGD)
8
16
24
32
To Be Delivered
After
June 1,
June 1,
June 1,
June 1,
1979
1980
1981
1982
A four-party contract has been drafted
which would provide waste water to meet
the cooling water requirements of the
Allen Power Project. The draft con-
tract calls for the sale of effluent from
the proposed County AWT plant. If, how-
ever, for some reason, the recommended
AWT plant were not constructed, then
174
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ESTIMATED ELECTRIC POWER CONSUMPTION (2)
1978
1985
1990
2000
Alt.
No.
Description
Max. Day Max. Energy Max. Day Max.Energy Max. Day Max.Energy Max. Day Max.Energy
Running Use Running Use Running Use Running Use
HP kwh/day(l) HP kwh/day(l) HP kwh/day(l) HP kwh/day(l)
2 Complete Treatment
3 AWT and Return to
Lake Mead
7 Combination Alternative
10 Amended Combination
Alternative
26,000 468,000 32,700 589,000 38,000 684,000 48,100 866,000
4,800 86,000 6,000 108,000 7,000 126,000 8,800 158,000
10,000 180,000 13,500 243,000 16,700 301,000 22,300 401,000
6,000 108,000 7,500 135,000 8,700 157,000 11,000 198,000
« •
ft* (1) kwh/day = HP x .75 x 24
(2) Power consumption is assumed to be proportional to flow
-------
POWER GENERATING PLANTS
FOR LAS VEGAS VALLEY
Name of Plant
and Location
Megawatts Presently
Available
Megawatts Available
to Nevada
by year 2000
Type of Plant
and Purpose
1. Clark Station
Las Vegas Valley
2. Sunrise Station
Las Vegas Valley
3. Mohave Stati on
near Davis Dam
4. Westside
Las Vegas Valley
5. Gas Turbines
Las Vegas Valley
6. Hoover Dam
at the Dam
7. Navajo Station
near Page, Arizona
8. Reid Gardner
Moapa Valley
9. Allen Power Project
(Proposed)
Total Nominal
Generating Capacity
in Megawatts
195
85
211
30
58
- 67 (May 1974)
100
261 (June 1974)
234
+ 112 (June 1975)
195
85
211
30
125
100
261
448 (1977)
2,000*
Steam Electric
Main Load (not.
gas & fuel oil)
Steam Electric
Main Load (not.
gas & fuel oil)
Steam Electric
Main Load (coal)
Diesel Electric
Peak, Emerg.
Gas Turbines
Peak, Emerg.
Hydroelectric
Main Load
Steam Electric
Main Load (coal)
Steam Electric
Main Load (coal)
Steam Electric
Main Load (coal)
1,241 mid 1974
1,353 mid 1975
3,455
Source- Nevada Division of Water Resources
* 500 Megawatts proposed to be available in 1979 with proposed expansion
to 2,000 Megawatts by 1983
table 25
-------
Nevada Power Company would purchase
secondary waste water for the Allen
Power Project and provide their own
AWT facilities.
It is estimated that Nevada Power Company
will purchase AWT plant effluent from
the County for about 31 £ per thousand
gallons ($308 per million gallons). Thus,
the estimated annual revenue to be realized
by the community (after 1982) would be
about $3, 500, 000 per year. This revenue
is to be applied to the costs of providing
the AWT required to meet the water quality
standards for Las Vegas Wash. The anti-
cipated revenues from the sale of reclaimed
waste water to the Allen Power Project
should reduce the costs to the community
of the recommended project by about 25-
30%.
Coal for the plant would reportedly be
low sulfur coal to be mined in Utah. It
would be transported to the site either
by railroad of by pipeline, or a com-
bination. Additional transmission lines
would have to be built to convey electrical
power to substations for distribution. They
would follow the existing lines from the
Reid Gardner Plant to Las Vegas.
A separate environmental impact state-
ment for this plant and power transmission
facilities would have to be prepared prior
to construction.
EVALUATION OF THE
VIABLE ALTERNATIVES
Each of the four viable alternatives meets or
exceeds the Octobe* 1973 waiter quality
standards for Las Vegas Wash set by
the State of Nevada and approved by the
EPA. In addition, each alternative meets
the project objectives and, in varying
degrees, the water management goals
and water quality objectives. The de-
gree to which each alternative meets the
project objective, water management
goals and water quality objectives is
discussed in the paragraphs which follow.
Engineering
Alternative 2, Complete Treatment,
would treat the waste water to a degree
which will allow direct reuse of the ef-
fluent. It would provide a flow of effluent
to Las Vegas Wash which would be of a
quality that would meet and exceed the
effluent limitations. This high degree
of treatment, however, would not be
without certain liabilities. This alter-
native would use large quantities of
electric power when compared to the
other viable alternatives. In addition,
it would use large quantities of chemicals
which are expensive, and in some cases,
in short supply. Finally, with the direct
reuse of reclaimed waste water for do-
mestic water supply purposes, there ex-
ists a potential health hazard. To date,
the nation's health authorities have not
approved any technique of direct reuse
of reclaimed waste water for domestic
water supply.
177
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MONETARY COST EFFECTIVENESS
OF FOUR MOST VIABLE ALTERNATIVES
Alternative
2
3*
7**
10**
7: — •
Present!/
Worth of
Description Capital Costs
Complete Treatment $155,216,000
AWT & Return to Lake Mead $ 87,288,000
Combination Alternative
(Export to Dry Lake Valley) 87,293,000
Amended Combination
Alternative $ 89,373,000
Costs Per Million Gallons Treated
Capital?/
Cost
$446
$248
$248
$254
M&O3/
Cost
$446
$128
$ 91
$130
Total
Annual
Cost
$912
$376
$467**
$339
$438**
$384
Directy
Annual
Revenues
unknown
unknown
($ 30)
($116)
Net
Annual
Costs
$912
$376
$437**
$309
$322**
$268
•/ Includes the present worth value of all elements to be constructed between now and the year 2000. The in-valley irrigation
system is common to all four alternatives shown in this table. In-valley irrigation represents a present worth capital cost of
$13,377,000 and is included in the cost shown above.
-/ Derived by computing the annual capital cost using the "capital recovery factor" for 22 years at 7% and dividing the annual
cost by the average annual flow for the period 1978 to 2000 which is estimated to be 31 ,025 mgy. In-valley irrigation is
equal to $33 per million gallons for all four alternatives.
•/ Includes $13 per million gallons for in-valley irrigation for all four alternatives.
•/ Based on average annual flow delivered to the proposed Allen Power Project of 1 1 ,680 mgy and rates as described in the
"draft" 4-party contract. (Calculation: 1 1 ,680 mgy x $308 f 31 ,025 mgy « $1 16)
**
Modified from Phase III Report; see discussion page VI-4.
Dr. Thorne Butler's comments in Appendix H.
1781
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Alternative 3 (Modified), AWT and
Return to Lake Mead, will remove suffi-
cient pollutants to meet the effluent re-
quirements for discharge to Las Vegas
Wash and, thus, will meet the water
quality standards, for Las Vegas Wash.
This alternative will have the lowest
first cost of the four viable alternatives
as well as the next to lowest operation
and maintenance cost. It also has the
lowest energy consumption. Reuse in
this alternative discharge is limited to
golf course irrigation which is presently
practiced with secondary effluent and
agricultural reuses. Industrial reuse
is limited to the two power plants which
are presently using secondary effluent.
No new industrial reuses are scheduled
with this alternative.
Alternative 7, the Combination Alterna-
tive, provides for exportation of secon-
dary effluent. This alternative has a first
cost about equal to Alternatives 3 and 10
and a low maintenance and operation cost.
Power consumption is higher than with
Alternatives 3 and 10. This alternative
provides for some beneficial reuse, both
for industrial and agricultural uses. The
quality of this water would limit its use
for irrigation purposes. The secondary
effluent would be available for delivery
to the Allen Power Project located near
the final disposal site at Dry Lake.
During the public hearings held in Au-
gust of 1972, there were objections to
the concept of exporting and evaporating
water from a desert community. This
alternative does include a maintenance
program for Las Vegas Wash; however,
the water used for this purpose will not
meet the effluent limitations for dis-
charge into the Wash. The water quality
standards for Las Vegas Wash could be
met by the removal of water from the
Wash by the proposed Wash ground-water
collection system and pumping station.
The Wash pumping station is located up-
stream of the sampling station at North
Shore Road, thus, water discharged to
the Wash for greenbelt maintenance is
withdrawn and returned to export sys-
tem for exportation to Dry Lake Valley.
This alternative includes pilot scale
AWT and desalination plants as well as
a pilot ground-water recharge program.
Information obtained from these pilot
facilities would be used to design future
facilities for expanded waste-water re-
clamation.
Alternative 10, the Amended Combina-
tion Alternative, provides AWT prior to
discharge to Las Vegas Wash. The
treatment process proposed would pro-
duce an effluent which would meet or
exceed effluent limitations, thus,
meeting water quality standards for Las
Vegas Wash. This alternative emphasizes
beneficial reuse including continuation and
expansion of irrigation in the Valley and
the providing of industrial cooling water.
Also included is a pilot desalination and
pilot ground-water recharge program.
This alternative has the second lowest
first cost and the third lowest annual ope-
ration and maintenance cost. This al-
ternative has the lowest net cost after
deducting revenues from the sale of re-
claimed waste water to the Allen Power
179
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Project. Energy consumption is com-
paratively low and this alternative offers
great flexibility for future waste-water
management programs.
Economic
Cost estimates and economic analysis
were prepared for each of the viable
alternatives in accordance with estab-
lished criteria. Cost estimates were
prepared for initial construction costs
and planned future expansions. The
Combination Alternative (No. 7) and the
Amended Combination Alternative (No.
10 both have direct income benefits from
the sale of waste water for use as power
plant cooling water. These revenues are
included in the monetary portion of the
cost-effective analysis.
A summary of the monetary costs of the
viable alternatives is shown in Table 26.
This Table lists present worth of pro-
ject costs as well as costs per million
gallons (mil gal) of waste water treated.
The capital cost per mil gal is developed
by calculating the equivalent annual costs
of initial construction and future project
expansion then deducting salvage value.
The equivalent annual cost is then divided
by the average annual waste water flow
over the planning period to derive cost
per mil gal. The same approach is used
to obtain maintenance and operation costs
per mil gal of waste water. The total equi-
valent annual costs per mil gal is the sum
of the annual capital cost and the annual
maintenance and operation cost. The
direct annual benefits or revenus are
developed from the terms of the April
1974 draft of the proposed contract for
the sale of AWT effluent to Nevada
Power Company. The net annual costs
are the difference between the total an-
nual costs less the direct annual revenues.
THE NPDES PERMIT PROGRAM
The Federal Water Pollution Control Act
Amendments of 1972 established the Na-
tional Pollutant Discharge Elimination
System (NPDES), a national permit
program. Section 402 of the Act re-
quires that municipal, industrial and
other point source discharges obtain
permits from EPA or its designated
State agency for the discharge of any
pollutant into the waters of the United
States. The Act also requires that
standards be established for discharges
from most pipe sources, including pub-
licly-owned treatment works. In the event
that the effluent standards are not suf-
ficiently stringent to provide for attain-
ment of established water quality stan-
dards in the receiving waters, effluent
limitations necessary to achieve comp-
liance with water quality standards must
be met. The date specified for achieve-
ment of secondary treatment, as defined
i,n regulations published pursuant to the
Act, or the treatment necessary to pro-
vide compliance with water quality stan-
dards, is July 1, 1977.
Since the flow in Las Vegas Wash will
be almost exclusively effluent from the
Clark County AWT Plant, and since
180
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water quality standards for Las Vegas
Wash are more stringent than secondary
treatment effluent standards, the plant
effluent characteristics will be limited
by the NPDES permit to the level spe-
cified by the water quality standards.
Other conditions of the permit will re-
quire: monitoring of the discharge on
a daily basis, with reporting of results
to EPA and the State Bureau of Environ-
mental Health; provision of safeguards
against electric power failure; and action
to assure compliance with industrial pre-
treatment regulations published by EPA
pursuant to the Act.
181
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'••':'• '"•''• • ' • A-.JW. . ••••••'•.•'%' "•.':":•••• i
182
-------
*
llffil^w.^™*'.'
iti
•- ••-•»..
" • V
*— . •» i> •»
-------
Central to the evaluation of the viable
alternatives proposed in the previous
chapter is the varying environmental im-
pacts that will result. Within this eva-
luation, both beneficial and adverse im-
pacts will be identified. Adverse impacts
which cannot be avoided will be highlighted
in Chapter 4,
For organizational purposes, the primary
impacts of the alternatives will be dis-
cussed first. Primary impacts are those
impacts which have a more immediate af-
fect on the environment as the result of
an activity and are of a comparatively
shorter duration than, let's say, sub-
sequent ramifications of that primary
impact. For example, noise of const-
ruction is a primary impact where the
resultant disturbance to wildlife may be
of a temporary nature. Both the primary
impact and immediately identifiable im-
pact subsequent to that primary impact
will be discussed in this section.
Secondary impacts will be discussed
next. A working definition of secondary
impacts, as opposed to primary impacts,
would be those impacts that are directly
related to primary impacts but may not
be readily apparent as impacts. To ex-
pand on the previous example of const-
ruction noises disturbing wildlife, a
secondary impact may be a change in
the balance of wildlife. In a long-term
analysis, more adaptive species would
possibly return to the impacted area
and less adaptive species would seek
new habitats. In such instances, the
need for human intervention to mitigate
and maintain balances within whatever
wildlife habitat remains would have to
be considered.
In addition to the adverse impact miti-
gation measures discussed in this chapter,
measures designed to mitigate the adverse
impacts will be considered in the next
chapter as well. This will facilitate iso-
lation of those impacts remaining even
after all available mitigation measures
have been undertaken.
PRIMARY IMPACTS
Impacts of Construction
Construction of waste water management
(ft
184
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facilities in developed areas causes noise,
dust, and inconvenience. These three im-
pacts can be minimized by careful sche-
duling of work so designed to affect
a minimum of people, watering to con-
trol dust, and requiring mufflers on con-
struction equipment. Other construction
practices which can avoid adverse impacts
are: Providing adequate safety protection
for motorists, cyclists, and pedestrians;
disposal of spoil in a beneficial manner;
and an enlightening education program to
acquaint residents with the necessity and
value of the project.
prohibitive. Where water tables must
be lowered to bury pipelines, the time
should be minimized so as to cause as
little damage as possible to vegetation
surrounding the area of construction.
The following impacts of construction
could result from any construction as-
sociated with any of the proposed viable
alternatives. The applicant's consul-
tants have recommended that the miti-
gation measures that are discussed below
be implemented.
Construction in deserts and marsh areas
causes noise, dust, erosion, spoil, loss
of vegetation and disturbance of wildlife.
These impacts can be minimized by re-
stricting the area of facilities under con-
struction at any one time, watering to
control dust, requiring mufflers on con-
struction equipment, restricting construc-
tion areas to minimize loss of vegetation,
and restricting disturbance of areas sub-
ject to erosion. Other practices which can
avoid these impacts include scarifying and
watering compacted soil to encourage new
plant growth; restricting equipment clean-
ing and maintenance to construction yards
equipped to dispose of oils, fuels, and
other^ substances harmful to vegetation,
and wildlife; and locating construction
stockpile areas to avoid areas of more
valuable vegetation. The impacts of soil
disposal can be eliminated or reduced
by carefully locating such areas for
beneficial uses or locating these dis-
posal sites where minimal impact would
occur. Soil could be used to construct
pond dikes if the haul distance is not
Temporary roads, equipment storage sites,
corporation yards, and construction sites
cause the loss of vegetation. Temporary
construction of this nature will destroy
the native vegetation, compact the soil,
and remove the top layer of soil. Re-
growth and revegetation is retarded and
can be further retarded by the dumping
of equipment fuels, cleaning fluids and
excess construction materials.
To minimize the impacts, all temporary
construction of access roads, equipment
storage sites, corporation yards, and
construction sites should be restricted
to the smallest compatible area. They
should be located in areas where the
least destruction of native vegetation
occurs. Disposal of all construction
wastes, equipment fuels, cleaning
fluids, and broken machinery parts
should be made at proper off-site dis-
posal areas. After these temporary
construction areas have served their
purpose, they should be restored to
185
-------
their original condition, or at least
blended into the adjacent land form.
Vegetation to be preserved adjacent
to temporary construction areas should
be identified and marked -with measures
taken to protect it.
The impacts from temporary access
routes, equipment storage sites, cor-
poration yards, and construction sites
could cause the loss of wildlife. Vege-
tation provides food and cover for ani-
mals. The clearing of vegetation from
construction work areas removes habi-
tats, therefore removing both food and
cover.
In order to minimize the impact upon
wildlife from temporary access routes,
equipment storage sites, corporation
yards, and construction sites, all tem-
porary construction should be restricted
to fhe smallest compatible area. These
temporary areas should be located where
there will be the least destruction to
wildlife habitat. The disposal of all con-
struction spoils, equipment fuels, fluids,
and scrap machinery parts should be done
at proper off-site disposal areas. After
temporary access routes, equipment
storage sites, corporation yards, and
construction sites have served their
purpose, they should be restored to
their original condition or at least blen-
ded into the adjacent land form. All
wildlife habitats adjacent to temporary
access routes, equipment storage sites,
corporation yards, and construction
sites should be identified and marked
with measures taken to protect them.
The deposition of construction spoils
on vegetation in undoubtedly destruc-
tive. The spoils "pile" in itself can
be aesthetically undesirable, espe-
cially when spoils are a poor quality
soil and natural vegetation regrowth
is virtually not occurring.
The location of spoil areas is critical.
A site should be chosen that covers the
least amount of vegetation, particularly
the vegetation used by animals for food
and cover. The location of the spoil
should not increase local land erosion
or contribute to erosion in itself. Spoil
areas should be molded to blend with
local topography and be seeded or
planted with localized native plants to
blend with existing native plant material.
Plant species chosen for revegetation
should be from those native species
which will flourish in the area and
provide food and cover for wildlife.
Fertilization and treatment of spoils
may be needed to ensure adequate
revegetation.
Dust created by construction activity
can blanket adjacent vegetation and
kill or injure the plants, thereby re-
ducing habitat (food, cover) for wild-
life.
Layers of dust on leaves reduce gas
exchange and photosynthesis in plants.
Plant survival potential is reduced, as
well as food and palatability to wild-
life. All construction sites, roads, and
corporation yards where dust is created
should be watered down as often as ne-
186
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cessary to keep fugitive dust to a mini-
mum.
Increased traffic on present roads and
on roads under construction could re-
sult in the destruction or displacement
of wildlife.
Increased traffic could increase the num-
ber of road kills of animals. A traffic
accident involving a large animal such
as a Desert Bighorn Sheep can also re-
sult in human injury. The activities of
construction. . . human activity,
heavy construction movement (sub-
surface vibration), noise, etc. . . .
will disturb resident animals causing
them to move out of the construction
area. If the adjacent area into which
the animals move is already at its
carrying capacity for that species the
population of the species will be re-
duced. For each species displaced,
the adjacent population of that species
will be affected. To minimize the
impact of increased traffic upon wild-
life, construction crews and other pro-
ject-related personnel should be made
aware of road-kill hazards. Roads in
construction areas should be posted with
warning signs for animal crossings.
Noise and construction activities should
be kept to a minimum needed to perform
the work. Temporary access routes,
equipment storage sites, and corporation
yards should be located in areas of low
wildlife density. Temporary fencing or
barriers should be placed at heavily used
wildlife crossings.
Construction activities such as movement
of diesel-powered trucks, earth movers
and associated equipment would create
short-term noise impacts on the area.
These noise impacts would last from the
time of construction commencement to
its completion. Wildlife would be af-
fected by noise from these trucks ad-
jacent to the areas of construction.
Feeding bird species and mammals
close to construction roads would likely
be displaced and may feed elsewhere
or return to the area after the noise
ceases. Sustained high noise levels
may affect animals that rely on the
use of auditory signals to detect and
locate prey, evade predators or stake
out territories.
Proper use of muffling equipment and
noise baffles on construction equipment
would aid in reducing some noise emis-
sion. In addition, the timing of con-
struction activities in relation to the
seasonal abundance and critical use
of the area by wildlife would also re-
duce the impact. In general, the time
of greatest impact would occur during
the spring breeding season.
Construction equipment used on a project
would be operated with the standards ex-
pressed in the Occupational Safety and
Health Act (OSHA) which stipulates per-
missible levels of sound and duration of
exposure to construction workers. Ad-
ditionally, construction activities should
only proceed during a 12-hour work period
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day during the normal week, thus eli-
minating the noise exposure to week-
end recreation and to local residents
after the daylight hours.
Air quality changes related to construction
activities are not expected to be signi-
ficant on the study area. In areas where
motorized equipment would be used, a
modification in particulate and oxidant
levels may occur. Any burning of brush
and waste material would create localized,
periodic area quality changes.
In order to minimize effects of construction
efforts on local air quality, burning acti-
vities should be limited to times when
atmospheric conditions are suitable and
when the practice is absolutely necessary
and material cannot be disposed of by alter-
native means such as shredding. The ope-
ration of diesel-fueled heavy equipment will
not result in any significant air quality de-
gradation.
The increase in human activity could cause
an increase of litter in the project and ad-
jacent areas. Construction personnel,
if careless, can significantly add to the
accumulation of refuse on the project site.
Bizzare occurrences such as birds caught
in plastic six-pack holders, small rodents
and reptiles with aluminum pull tabs ador-
ning their bodies, along with the refuse ~
littered road sides are indicators of care
lessness. If trash is allowed to collect,
an increase in flies, rats, and mice can
be expected.
To minimize the impact from increased
human activity in the project area and
adjacent areas, refuse containers should
be readily available at all project con-
struction sites. Refuse containers should
be placed at all temporary observation
areas. Frequent collection and disposal
of refuse should be practices. All con-
struction crews should use trash disposal
facilities and encourage visitors to use
the facilities provided.
Associated with the increased human ac-
tivities is the degradation of the environ-
ment by human wastes. All of the re-
medial, protective, and mitigation
measures discussed for increased human
activities should be applied, along with
the provision for adequately and conve-
niently located sanitation facilities for
use by construction crews and visitors
at construction sites and temporary vi-
sitor facilities. Human traffic may re-
sult in some destruction of the existing
vegetative cover. All vegetative spoil
which is removed will be chipped and
spread in a manner which will not pre-
sent a future fire hazard. No spoil will
be burned.
Impacts Of Project Features in Common
As was discussed in the previous chapter,
of the ten alternatives, four alternatives --
No. 2 - Complete Treatment; No. 3 - Ad-
vanced Waste Water Treatment and Return
to Lake Mead; No. 7 - Combination Alter-
native and; No. 10 - Amended Combination
Alternative -- were considered viable.
The criteria for selection and screening of
the alternatives that was done by the Appli-
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cant and presented in Table VI-I of the
Facilities Plan Annex A submitted to EPA
in July of 1974 is reproduced in Table 23
and is concurred in by EPA. In addition,
EPA's evaluation of the alternatives ap-
pears in Chapter 2.
Therefore, the impacts of the viable al-
ternatives will only be discussed, as well
as the alternative of "no action" in keeping
with the letter and intent of the National
Environmental Policy Act of 1969. Due
to the need of the community to comply
with the overriding immediacy of the EPA
Pollution Abatement Notice to clean up
the discrete pollutant contributions to
Las Vegas Bay, as well as maximize the
reuse and beneficial return of waste water
within the hydrologic system, it would be
extraneous to discuss the entire range
of alternatives when certain alternatives
would not be capable of satisfying these
basic requirements.
Common to all of the viable alternatives
that have been selected in the previous
chapter are the impacts relating to the
(1) collection system conveying wastes
from the existing sanitary systems to the
AWT Plant, (2) the advanced waste treat-
ment plant itself and (3) the in-valley
irrigation system. These impacts on the
environment are discussed below, with
modifications peculiar to each alternative
presented in the discussion of each alter-
native. In addition, the impacts asso-
ciated with pilot desalination and ground
water recharge (Alternatives 7 and 10)
and export to Dry Lake (Alternatives 2
and 7) are discussed herein;
Waste Water Collection System Impacts
Since the waste water collection pipelines
will all be buried underground, the long-
term surface and visual impacts will be
minor. The pipeline alignment will be in
such a manner to minimize disturbance
to native plant communities.
The Henderson Pump Station and the AWT
Surge Pond will create some visual impacts.
These visual effects can be reduced by
providing attractive design in landscaping.
The surge pond will permanently remove
approximate 8 acres of vegetation and
wildlife habitat.
The ponds, pump stations and treatment
facilities will increase the ambient noise
level in the area. The pump stations
should generate noise only noticeable up
to 300 feet from each station. The AWT
and desalination plant would create a
smaller amount of noise.
The pump stations to be constructed at
the Henderson Treatment Plant and the
Las Vegas Wash subsurface drain will
increase the ambient noise levels of
these two areas to a small degree.
These facilities would create some
amount of odor. Odor created is
dependent on many factors, mainly the
degree of treatment, the quality water
received before entering the reservoir.
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A noticeable odor immediately around
the surge pond is expected. If the re-
servoir becomes odorous, aeration may
solve the problem. Aeration may also
create some odors if there is a great
amount of organic material in the waste
water. Chlorination and reduced aera-
tion would reduce odors to the greatest
extent.
Periodic pond cleaning should be practiced
to remove accumulated solids and algae.
These solids should then be transported
to a designated sanitary landfill or to the
sludge disposal pond. Furthermore,
design of the surge pond should specify
that the pond be deep enough to prevent
substantial algal growth on the bottom
Algae growth can be effectively controlled
by using short retention time in the pond.
The asphalt lined ponds will prevent
waste water high in salts and nutrients
from percolating into the ground-water
system at this site.
If a power shortage longer than 24 hours
were to occur, spillage into the Wash
and then into Lake Mead would occur.
Fropi
Advanced Wasti
Water Treatment Plant
The addition of an advanced waste water
treatment facility to the existing secondary
systems of the City of Las Vegas, Clark
Bounty and Henderson, will aid greatly in
reducing water pollution to the Las Vegas
Wash and Bay. Thi's is considered to be
a long-term, beneficial impact. In addition,
by providing a centralized AWT facility,
the effluent quality can be more carefully
controlled as compared to the higher vari-
able quality of effluent produced from the
three existing systems. Instead of having
three separate points of discharge as with
the existing system, the proposed system
will have only one.
The AWT system will provide for a sub-
stantial flexibility in the treatment and
management of waste water in the Las
Vegas area. The modular design of the
plant will ensure that proper sewage dis-
posal is maintained as the population of
the Las Vegas Wash increases by allowing
for both expansion of capacity and the
addition of new treatment devices as
required.
Construction of the AWT Plant will necessi-
tate the conversion of 80 acres of irrigated
pasture and adjoining salt bush, seep-weed
and bassia close to the Wash. This land
use change will result in a displacement of
grazing practices and the wildlife species
associates with the agricultural practices
and the adjacent natural vegetation.
The AWT Plant processes may create
some unpleasant odors which will have
impact upon the surrounding area. The
generation of odoriferous gases is likely
to be minor and difficult to assess due to
the close proximity of the existing secon-
dary treatment facility (trickling filters)
which at the present time create offensive
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odors to adjacent residents. Any odors
that are created can be alleviated by the
use of sanitary operational techniques,
chlorination and injection of deodorizing
chemicals into the air, and fuel air collec-
tion and treatment.
are not yet finalized. However, with the
addition of a refractary lined cyclone
followed by a wet scrubber, the most
stringent emission regulations of Clark
County (Ringlemann No. 1) should be
satisfied.
The expected impact from noise created
by AWT operations is expected to be
slight. The only noise sources will be
from pumps, fans and motorized vehicles.
All equipment concerned with the operation
and treatment that would generate noise
will be located within buildings insulated
or baffled to reduce noise.
In the advanced waste water treatment
plant, the calcining furnace for Alterna-
tives 3 and 10 is the greatest source of
uncontrolled particulate emissions. A
multiple-hearth furnace is to be used and
the emissions from, it are characterized
as moderate to heavy. The calcining
temperature is sufficiently high to cause
the discharge of a high proportion of sub-
micron particulates which makes the
control problem difficult. In the process
it is intended to recycle the CC>2 -content
gas stream, from the calciner. However,
there will be periods, during initial
startup, shut-down, for equipment
malfunctions, etc. when the gases will
be discharged to the atmosphere. There-
fore, the particulate emissions control
equipment must be designed for such
periods.
The processing rates, discharged loading
and gas flow rates of the calcining furnace
A properly .designed wet scrubber would
ensure collection of the submicron parti-
culate. The liquid effluent from the
scrubber can be recycled to the process.
The lime feeding, transfer, and flaking
operations could be particulate emission
sources if conventional control equipment
were not provided. Through the use of.
fabric filters for the feeder and pneumatic
and/or mechanical transfer equipment
practically "zero" emissions can be
achieved.
Truck delivery and make-up lime to the
calcining systems can pose a serious par-
ticulate emission problem, depending on
the truck type. If a fully-enclosed back
vented pneumatic delivery type of vehicle
is used, then the emissions will be neg-
ligible. However, a dump-truck will
require an effective shrouding and ven-
tilation system to minimize the escape
of the very fine calcium oxide (CaO) par-
ticulates during the unloading operation.
This material poses a health hazard and
an air pollution potential so that its con-
trol will probably fall under OSHA juris-
diction. With an effective hood and ven-
tilation system, the material can be easily
collected in a fabric filter.
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The presence of the AWT plant will create
a visual impact on the area; however,
since the facility will be adjacent to an
existing treatment plant, the visual effect
will be reduced substantially by using
proper architectural design and landscap-
ing. Where possible, the structures should
conform to the surrounding desert envi-
ronment. An attempt should be made to
use local native vegetation in landscaping.
There is no NPDES permit at the present
time for the proposed discharge and there
are no official effluent limitations; however,
an effluent quality equal to the water quality
standards of the Las Vegas Wash would be
acceptable for meeting any permit require-
ments.
All alternatives meet the Best Practical
Waste Water Treatment Technology
(BPWWT) requirements for treatment and
r_euse of waste water. In this alternative,
heavy emphasis has been placed on recla-
mation and multiple beneficial reuse of the
waste water resource.
Wash, be instituted, for all of the
viable alternatives.
Impact on Las Vegas Lands to be
Irrigated
Operation of an in-valley irrigation system
utilizing AWT effluent would have all the
benefits of the irrigation system proposed
in the other alternatives. It would pro-
vide the same benefits as 2 and 3, and
additional benefits to those of Alternative
7 due to the higher quality of the water.
The health hazards associated with irri-
gation using secondary effluent would be
substantially reduced; in fact, use of
AWT effluent should not impose any
undue risks to health because of the high
level of treatment and reliability that
exists with this process.
Increased irrigation of lands in the
Las Vegas Valley will create new
surface impacts. Those that do occur
will be either beneficial or subtle.
Post aeration with chlorination will be
used after advanced waste treatment to
destroy pathogenic organisms and to
remove nitrogen in its ammonia form.
Residual chlorine can cause toxic ef-
fects on fish in Las Vegas Bay, how-
ever this can be minimized by ensuring
that the chlorine addition is carefully
controlled and that maximum mixing
occurs with the Bay. EPA has recom-
mended that post dechlorination prior
to discharge of the AWT effluent to the
Perhaps the most prominent impact
will be the increase in green areas
throughout the City. To many people,
the presence of green belts are an
amenity and a definite asset to the
populace since they provide areas for
recreation and a visual relief from
the surrounding city or the starkness
of the desert.
The application of additional water in
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a normally dry, hot climate may produce
subtle, microclimatic changes, parti-
cularly in terms of the humidity and tem-
perature in the area where water is
applied. This will constitute a minor
impact; however, in an area of exten-
sive irrigation the effects could be
monitoried.
Ground water flowing toward the Las
Vegas Wash as a result of irrigation
could result in some changes in vege-
tation wherever more water becomes
available to plants. This could likely
occur in areas downslope and adjacent
to lands to be irrigated. These changes
may occur subtly or where there is
substantial irrigation runoff, the vege-
tation changes may be substantial.
Some areas presently irrigated with
secondary treated waste water may be
converted to AWT water as it becomes
available. This conversion will create
some beneficial impacts, one of which
will be a significant reduction in the
presence of odor now created by appli-
cation of secondary water. Also, the
elimination of soil clogging by nutrients
and suspended solids may be realized.
Of principal importance is the reduced
health hazard in irrigating with a highly
treated waste water.
Irrespective of what alternative is se-
lected as the proposed project, pipelines
will be constructed to deliver reclaimed
waters.
By the year 2000 the theoretical require-
ments of the In-Valley irrigation system
could surpass 70, 000 acre-feet per year.
Expansion of neighborhood and regional
parks within the Valley could add as
much as 9,000 acres of grass and green-
belt to the existing system.
More realistic projections of the anti-
cipated new irrigable acreage which
could easily be served by AWT plant
effluent, indicates that a maximum of
25, 000 acre-feet per year of reclaimed
waste water could be disposed of within
the Valley by 2000. On completion of
all stages of In-Valley irrigation an
annual supply of about 20, 000 acre feet.
is anticipated. The main factors dis-
couraging a more extensive irrigation
system include:
OSites which are too remote from the
effluent sources
OSmall size of many of the new sites
will make the service costs pro-
hibitively high.
The most beneficial aspects of In-Valley
irrigation are from water conservation
benefits. Every acre-foot of reclaimed
waste water which is used for irriga-
tion purposes is one less acre-foot which
will have to be taken from the potable
water supply. In-Valley irrigation is
beneficial because it is a recycling
process of a scarce resource.
From the adverse side, any increase
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in the irrigated acreages within the
Valley will be ultimately reflected in
poorer water quality of the waters
within Las Vegas Wash. In previous
sections it has been shown that the
soil column within the basin is vul-
nerable to salt leaching to the environ-
ment from surface irrigation.
Due to the geology of the Valley, it is
believed that some of the near surface
groundwater will ultimately migrate down
gradient and discharge into Las Vegas
Wash. The increased salts which are
added to the system due to the initiation
of irrigation practices will contribute
greater TDS concentrations to the near
surface groundwater.
of the potable aquifers continue to drop,
there is also the possibility of the near-
surface aquifer recharging the deeper
zones due to the shift in potentials.
Prior to the implementation of any of
the proposed projects, it is recommended
that a network of observation wells be con-
structed adjacent to selected In-Valley ir-
rigation sites. This network should be
designed to monitor the near-surface and
a shallow aquifer system contiguous to the
irrigated areas. Several monitoring well
nests should also be constructed adjacent
to Las Vegas Wash down gradient from the
irrigated areas so that the movement and
quality of the return flows can be traced.
Much of the groundwater within the near-
surface aquifer system is located in areas
physically remote to the Las Vegas Wash,
and the fact that these shallow aquifers
are often made up of sediment with low
permeability will tend to offset the near-
future salinity impact. There are sec-
tors of the Valley where it might take
hundreds of years for the salt (within
the near-surface aquifer) to migrate
to the Wash.
Therefore, any effort to increase the
irrigated acreage within the Valley can
only move in the direction of greater
degradation of the waters in the near
surface aquifer system. This is the
case whether the irrigation water
supply is potable water or reclaimed
waste water. If the piezometric levels
Construction of a minimum network of
wells will provide the County with the
necessary baseline data (both water table
elevation and water quality measurements)
prior to initiation of the In-Valley ir-
rigation element.
A tentative water quality sampling pro-
cedure should be adopted to ensure that
the representative data is collected from
each observation well. These procedures
along with the location of sampling stations,
frequency of sampling, and constituents to
be monitored should be delineated in the
plans and specifications submitted to
EPA.
Impacts of the Pilot Desalination
Program
A pilot desalination program is proposed
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in conjunction with this alternative to
accomplish the following objectives:
1) Determine the feasibility of desalting
AWT effluent; 2) Evaluate the specific
desalination pretreatment requirements;
4) Investigate health hazards and; 5) In-
vestigate environmental impacts of a
desalination operation.
The plant would produce about 1.0 mgd
of high quality reclaimed waste water.
This would provide sufficient capacity
for the proposed pilot ground-water
recharge program.
The pilot desalination plant would cover
approximately two acres of land. This
would represent a permanent commit-
ment of land resources and the elimina-
tion of existing vegetation and wildlife
species.
The operation and maintenance of the pilot
plant facility would produce increased
noise levels in the area. The source of
this noise will include feed pumps, degasi-
fier blowers and numerous other equip-
ment such as the pumps necessary for the
flushing, cleaning, chlorine booster and
waste-brine processes. The estimated
noise emissions of the desalination equip-
ment should be determined and plans
developed to reduce the noise levels by
use of housing and baffles.
Operation of the pilot desalination faci-
lity would require additional electrical
power. Estimates of electrical needs
are ISKWHper 1, 000 gallons of desali-
nized water produced. Expected produc-
tion of desalted water would be 1 mgd
which will require approximately 13, 000
kilowatts per hour of electricity per day.
The desalination facility would produce a.
highly concentrated waste brine which could
be disposed of in one of three ways:
1) Lined evaporation ponds near the desalt
plant, 2) Removal to AWT sludge disposal
ponds and; 3) Discharge to the City waste
water collection system. The brine
waste would include concentrated salts,
heavy metals and possibly small amounts
of chemicals and resins. If a brine
evaporation pond facility is used, the
water would be evaporated with the brine
residues left behind. These deposits
would have to be periodically removed
and disposed of at a selected land fill.
Since the specific characteristics of the
waste brine are not yet known, a contin-
uous monitoring program would have to be
conducted to measure heavy metals, total
dissolved solids and other water quality
parameters during the pilot plant operation.
If heavy metal concentrations are found to
be excessively high, removal by precipita-
tion or other processes may be necessary.
The pilot desalination plant would likely
emit small amounts of water vapor from
the degasifier unit and blowers. This
constitutes a minor impact.
As a result of construction of the pilot
plant, some long-term visual changes
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in the area would occur. The area is pre-
sently a well field with a power substation
and water tank. Landscaping and archi-
tectural design of the structure would
minimize any undesirable appearance fea-
tures of the plant.
Impacts of the Pilot Ground-water
Recharge Program
A pilot ground-water recharge program
is also proposed as an integral part of
this alternative. This alternative is pro-
posed to accomplish the following objec-
tives: 1) Determine the feasibility of
recharging high quality reclaimed waste
water into the Valley's ground water
formation; 2) Formulate recharge
methods of injecting effluent water for
future use as a supplemental water supply
and; 3) Determine water quality require-
ments for recharging water.
The experimental recharge well site and
related facilities would permanently elimi-
nate approximately two acres of wildlife
habitat in vegetation. Since much of
the area has been significantly disturbed,
this impact would not be significant.
The recharge well and facilities would
cause a permanent change in the visual
environment of the area. In order to
minimize the impact of the well housing
structure on the surrounding environment,
the facilities should be designed to conform
with the desert environment and to be as
unobtrusive as possible. The area should
be landscaped to include shrubs and trees
that would aid in shielding the structure
from adjacent residential areas.
Pumps and related equipment may create
noise levels that would adversely affect
adjacent residents. In order to properly
determine the expected noise levels of the
equipment, noise sources should be iden-
tified and the estimate noise output deter-
mined. It would then be possible to deter-
mine methods such as enclosing pumps
or providing baffles to reduce noise levels
that are above ambient and considered
to have an adverse effect.
Subsurface impacts due to operation of
the injection wells for Alternatives 7 and
10 are largely problematical. Injected
water may cause some changes. The
two waters may be chemically incom-
patible and may dissolve additional min-
erals from the aquifer; or they could
react to form a precipitate that would
cause clogging of the injection wells.
Testing of the two waters and additional
treatment of the waste water, if neces-
sary, would eliminate this impact. Con-
tamination of subsurface waters can be
avoided by injecting water of at least
equal quality to that of the selected
aquifer.
Injected water will be warmer than that
of the middle aquifer. The impact of this
is not known. Recharge of the middle
aquifer utilizes short-term storage of
water to be withdrawn and beneficially
used by man; it provides some biological
treatment, reducing bacteria, viruses,
and remaining organic material; slows
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the rate of subsidence in the ground
caused by continual depressurization from
pumping out of the middle aquifer, if
injected near production wells; and moves
towards offsetting the trend of depleting
ground-water resources.
A comprehensive monitoring program,
if implemented, will identify any impact
which may occur.
The experimental recharge well would
be drilled into the middle aquifer (500 to
700 feet below ground surface), and sized
to recharge 1. 0 mgd of desalted effluent.
It is estimated that the product water from
the desalination plant would have a TDS
concentration in the range of 300 mg/1.
This is close to the background level of
potable ground water of the middle zone
in this sector of the Valley. A series
of ground water observation wells would
be installed in the vicinity of the recharge
wells to monitor the effects of the injec-
tion operation on the ground-water system.
This monitoring would permit identification
of any potential degradation of the potable
water supply.
Implacement of renovated waste waters
by well injection into the middle zone of
aquifers could enhance the environment
by conserving reusable waters that nor-
mally would have been discharged out
of the Basin. A continuous discharge
of 1 mgd would add 1, 120 acre-feet per
year of potable water into the basin
water supply. Since the product water
utilized for injection is close to the
background TDS level of the middle zone,
there would be no adverse salt balance
effec.ts due to this operation.
During the initial stages of the experimen-
tal recharge operation, the recharge well
would be supplied with ground water.
A system of observation wells should be
provided to evaluate the response of the
ground-water systems to the recharge
operation. This system of monitoring
wells could permit termination of opera-
tion in the event that undesirable effects
or problems develop.
Impacts of Dry Lake Disposal
The following discussion concerns the
impacts of Alternatives 2 and 7 in using
the Dry Lake area, a closed basin sink
to the northwest of Las Vegas, for waste
water and/or brine disposal.
Ponds located on the alluvium above the
lake beds will have pervious dikes and
pervious bottoms. Evaporation will
increase salt concentration somewhat,
but continual percolation will prevent
significant salinity buildup. Water which
percolates in Dry Lake, will reach a clay
lens and flow underground towards the
center of the lake bed (or if there is no
clay layer, as in Jean, Hidden, and El-
dorado, will percolate downwards to join
the deep ground-water system). Where
good clays exist in the lake bed (Dry Lake
and Eldorado Lake), water logs will occur
by evaporation, allowing salts to contin-
uously build up in the lake waters. The
salinity in the evaporation ponds will
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gradually change from relatively low in
the higher pond, to relatively high in the
lower pond. Storm flows may occasionally
dilute concentrations in the lake beds, but
presumably storm runoff will be kept out
of the ponds.
Of special interest to the ecology of the
treatment ponds are toxicity, nutrients,
dissolved solids, and temperature.
Acute toxicity from waste water is not
expected to occur in the ponds if they
are operated to make use of the volume
of dilution made available through long
detention and detoxification with time.
Several physical factors peculiar to this
situation will affect the functioning of
the pond. Among the most significant
are solar radiation, wind speed and dura-
tion, soil type, and the actual configura-
tion of the pond. The sun shines 86% of
ther time during the year with average
air temperatures ranging from below
45° to over 100° Fahrenheit. Insofar
as sunlight and temperature are con-
cerned, biological systems may function
at high rates throughout the year. Water
temperature in the pond is expected to
vary seasonally from 50° to 90° Fahren-
heit. However, pond temperature will
be influenced by wind behavior and water
depth. Conceivably, water temperatures
in shallow portions of the pond may at
times exceed 90°. Prevailing winds in
the 7-10 miles per hour range are ex-
pected to cause daily mixing of pond
waters. Winds in the Las Vegas area
may rise to 40-50 miles per hour, and on
these occasions bottom sediment may be
resuspended and cause increased levels
of turbidity.
In cross-section, the ponds on the allu-
vium will be shaped like a wedge. The
shallow water portion of the pond will
influence its physical and biological na-
ture. Heat adsorption and the stirring
of bottom sediments will be greater in
the shallow end of the ponds.
Depending on the degree of light pene-
tration, mats of blue-green algae and
colonies of sulfur bacteria may grow in
the bottom. Plants which grow up and
out of the water, such as cattail, tule,
and cane, may also occupy shallow por-
tions of the pond. Both the growths of
bottom dwelling blue-green algae in marsh
plants will have adverse impacts on the
evaporative purposes of the ponds, and
the dissolving of oxygen in the pond water.
Mats of blue-green algae may break loose
from the bottom and float on the surface
where they give off a foul odor. They
also die and become resuspended in the
water where they decay, consuming oxy-
gen in the process. This decay, when
combined with other factors, may cause
the pond to go anerobic (stagnant).
Upright growing plants contribute to the
filling of the pond with sediment, by pro-
ducing and holding suspended material.
During the winter, these plants die and
contribute decomposable organic matter
to the system. However, such plants
198
-------
provide food, cover, and.nesting habi-
tats to aquatic wildlife. Biological pro-
ductivity of higher plants and animals
in the lower level ponds and lake bed is
likely to be restricted by the level of
total dissolved solids (TDS) which is
expected to be 5, 000 mg/1 when opera-
tion begins.
Over the next five-years, it may build
up to 45, 000 mg/1 in the'lake bed. A
TDS of 5, 000 mg/1 is expected to sus-
tain plant growth and to provide drinking
water for birds and terrestrial animals.
l£ is not expected to provide habitat for
common species of game fish. Certain
fish which are able to tolerate wide ran-
ges of salinities may be introduced in
the Lake to control insects and other
aquatic vertebrates, but they will not
provide recreational use. Research
would be needed to find game fish spe-
cies such as the Corvina of the Salton
Sea that could survive in the pond.
A rise in salinity from 5, 000 to 45, 000
mg/1 is expected to reduce and eventually
eliminate vascular plants from the lake
bed and lower pond. As was predicted
for the Salton Sea in California, a TDS
of 45, 000 mg/1 is the upper limit for
marine fish that may live in such highly
enriched waters. Consequently, at a
TDS of 45, 000 mg/1, biological com-
munities in the Lake would be reduced
to simple communities of salt-tolerant
algae and invertebrate animals.
During the biologically productive life
of the ponds (long-term for higher ponds,
five years for lower ponds), water fowl
and native wildlife are expected to use
the ponds as a habitat. A potential for
water fowl botulism (a disease caused by
bacterial toxins) exists in warm shallow
enriched ponds of this type. However,
this type of botulism may be prevented
by the proper design and operation of
the pond.
A riparian type of habitat (typical of
stream banks) consisting of salt cedar
and cat claw mesquite is expected to
develop near the ponds. This vegetation
will provide habitat for native animals
and increase their density in the vicinity
of the project. Irrigation streams would
have to be implemented to provide con-
trolled plant growth.
Recreational uses of the pond area are
expected to be limited to viewing the
scenery, birds, and terrestrial wild-
life that will be associated with the pond.
A study should be implemented at the time
of construction and initial operation to
determine the design and operating condi-
tions that will provide optimum recrea-
tional benefits.
Because of the shallow depth and the
prevailing winds, the lake beds would
be turbid and the level of biological
productivity is uncertain. With salt
concentratiaons reaching high levels,
greater than 45, 000 mg/1, the Lake
would become biologically of little
value after about five years.
199
-------
After desalination is added to the treat-
ment process, slug flows of brine and
some waste water will be pumped to the
playa lake. This water is not expected
to support life. Because of mixing by
wind, it is likely to appear as a lake
of muddy water surrounded by a white
band of salt crystals. Some water fowl
may use the lake surface for a resting
area.
Water Quality
The elimination of secondary waste-water
discharges to Las Vegas Wash will have a
number of beneficial impacts on Las Vegas
Bay, all of them related primarily to the
quality of the advanced treated effluent.
The higher quality characteristics of waste
water entering the Las Vegas Wash are
expected to change significantly the cha-
racter of the Wash. Initial changes will
likely be minor since the water quality in
the Wash is determined, in part, by
ground-water inflows from a number of
sources. The residual effect of the poor
quality water will be slowly eliminated
over time as the AWT water has a diluting
effect.
Perhaps the most significant change will be
the reduction in amounts of phosphorus en-
tering the Bay. According to Deacon and
Tews (1973), approximately 814 pounds of
phosphorus enters Las Vegas Bay daily
from the Wash. This amount would be
significantly greater if it were not for the
the vegetation in the Wash which assimi-
lates a large portion of the phosphorus.
Existing phosphorus discharges from the
City of Las Vegas and Clark county treat-
ment plant are from 9 to 11 mg/1. Future
discharges will be 0.5 mg/1 or less.
Other water quality parameters will
include suspended solids, biochemical
oxygen demand, chemical oxygen demand
and total dissolved solids; however, the
reduction of TDS is likely to be minor in
comparison to the total quantity reaching
Las Vegas Bay daily. The amount of
nitrogen entering the Bay has been esti-
mated at 3, 234 Ibs. per day according
to Deacon and Tews. Some reduction
will likely occur as a result of AWT dis-
charge; however, a significant portion
of that amount is known to come from a
non-point source near the BMI evapora-
tion ponds. The effects of changes in
water quality will, therefore, constitute
beneficial impacts on Las Vegas Bay.
In addition to the expected changes in
discharges to the Wash, the quality
of the effluent will differ significantly
from existing effluent characteristics.
Table 27 lists the quality of the effluent
from the treatment plants to be centra-
lized and the effluent quality expected
from advanced waste water treatment.
As previously mentioned, one important
characteristic will be the reduction in
the amount of phosphorus in the effluent
from the existing 9-10 milligrams per
liter (mg/1) to approximately 0.5 mg/1.
200
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EXISTING AND FUTURE WASTEWATER CHARACTERISTICS
OF CITY OF LAS VEGAS, CLARK COUNTY SANITATION DISTRICT,
HENDERSON, AND ADVANCED WASTEWATER TREATMENT PLANTS
City of
Henderson
Future AWT
Effluent Parameter
Suspended Solids
Biochemical
BOD oxygen demand
Chemical
COD oxygen demand
PO as P
NH as N
Total
TDS dissolved solids
Alkalinity as CaCO
Hardness as CaCO
Calcium as Ca
Temperature (influent)
pH
Chlorine residual
LAS
Coliform
Dissolved oxygen
Unit
mg/1
mg/1
mg/1
mg/1
mg/1
mg/1
mg/1
mg/1
mg/1
°C
mg/1
mg/1
mg/1
Clark Co.
38
30.5
128
10.7
16
1831
236
546
124
25.2
7.5
2.4
2.3
-
-
Las Vegas
18.4
14.7
NA
9
18
1058
247
413
80
22.7
7.6
1.0
NA
-
-
#1
NA
NA
NA
NA
NA
2293
319
825
305
NA
7.2
NA
NA
-
-
#2
NA
NA
NA
NA
NA
1000
240
270
100
NA
7.
NA
NA
(average month!
2.0
10.0
40
0. 5
-
1425-1725
-
-
-
27.0
4 6.5-8.5
-
-
200/100
5.0
201
-------
This is evident by the low phosphorus
levels at North Shore Road. The most
likely affect of phosphorus reduction
would be the loss of vigorous vegetative
growth and possibly some die-off and
composition changes. Because the
definite effect of reduction of phosphorus
levels to 0.5 mg/1 cannot be determined
without monitoring of vegetative trends,
this will constitute a problematical
impact.
When possible means of mitigating the
effects of phosphorus reduction, if it
was found to be a problem, would be
the periodic discharge of controlled
quantities of secondary waste water
from the City of Las Vegas Treatment
Plant. These releases would have to
be made to provide the necessary
nutrients to maintain vigorous vege-
tative g rowth without exceeding the
water quality standards for Las Vegas
Wash.
The discharge of AWT water in place of
the secondary treated water will improve
the desirability of the Wash in terms
of aesthetic quality. This will constitute
a beneficial impact. The presence of
odoriferous and unpleasant looking waste
water reduces the desirability of the
area at the present time. Advanced
waste water treatment will greatly re-
duce both of these unpleasant features.
The availability of good quality water will
enhance the recreational and educational
opportunities in the Wash. This is con-
sidered a beneficial impact. The Wash
Development Committee, in a recent
report outlined the educational and rec-
reational development goals for the Wash
based on the identified qualities of the
area and the desires of the population.
The improvement of water quality in the
Wash will reduce the health hazards po-
tential. Advanced waste water treatment
will significantly reduce biochemical
oxygen demand and bacteria that was
present in the secondary effluent. By
decreasing the nutrient discharges, the
likelihood of bacterial growth will be
diminished. This will constitute a long-
term beneficial impact.
Total dissolved solids or salinity rea-
lized through the advanced treatment of
waste water discharge to Las Vegas Wash
will result in a TDS reduction of 150 mg/1
and have a beneficial impact on the Colo-
rado River. The importance of control-
ling salinity throughout the Colorado River
Basin goes without saying as borne out
by the discussion in Chapter 1. It is
estimated that the present economic im-
pact of salinity for each milligram per
liter increase in salinity at Imperial Dam
may be as much as $160, 000. Las Vegas
Wash presently contributes an increase
in salinity at Imperial Dam of 17-18 milli-
grams per liter.
In addition to the reduced salinity of ad-
vanced treated waste water discharge to
Las Vegas Wash, export and beneficial
reuse of waste water as envisioned in
proposed alternatives 7 and 10 will divert
202
-------
additional salts from the -Colorado River.
The reuse of waste water for cooling in
the Allen Power Generating Facility will
divert over 60,000 tons per year of salt
from the river. In-Valley irrigation
will divert over 235, 000 pounds of salt
per day; however, some portion of this
diversion may return to Las Vegas Wash
as diffuse subsurface flows.
Water Quantity
Any substantial increase in water vol-
ume entering the Wash would change
the width of the stream and velocity of
the flow. This increase in water will
also create changes in the vegetative
composition of the Wash. Areas now
supporting the more arid plant species
will likely shift to more moisture de-
pendent species. The provision of a
greater quantity of water in the Wash
would allow for a. greater variety of
usage for wildlife and recreational en-
hancement in the Wash. There would
be considerable beneficial impacts.
The substantial reduction or elimination
of the flows into Las Vegas Bay from
Las Vegas Wash will change the present
characteristics of the Bay. Acute die-
off of algae in Las Vegas Bay could occur,
but will depend on the time of year that
the flow is eliminated. A die-off would
be most likely to occur if the flow is
eliminated during the summer months.
Such a die-off would be of a temporary
duration lasting from two weeks to a.
month. Odorous die-off could be avoided
by eliminating the flow in the Wash during
the winter months.
Under modified Alternative No. 3, signi-
ficantly more AWT water than provided
for in the other alternatives would flow
down Las Vegas Wash to Lake Mead.
This is because there would be less pro-
visions for beneficial reuse of water
in modified Alternative 3 than in Alter-
native 2, 7 or 10, and no export out of
the basin.
During the initial phase of operation,
the amount of AWT water to be dis-
charged to the Wash and ultimately to
the Bay, will be greater than existing
releases of secondary treated water.
This waste water return to Lake Mead
may be credited to the amount of
water diverted to the Las Vegas Valley
from the Colorado River. This water
will also contribute a slight amount to
the generation of power at Hoover Dam.
These will both be beneficial impacts.
Due to alternations in the points of waste
water effluent discharge and quality and
quantities of discharge, changes in the
Las Vegas Wash are likely.
It has been well established that monthly
and annual fluctuations in waste water
flows to the Wash have occurred in the
past and will continue to change with the
increase in water demand, reduction of
non-point discharges to the Wash and
greater demand for waste water reuse
in the Las Vegas Valley. Table 29 shows
203
-------
?m
Year
1979
1980
1981
1982
1983
1985
2000
-------
the changes in flows to Las Vegas Wash
for the years in 1971 through 1973. These
flows are expected to continue to increase
as the population in the Valley grows.
One of the most important aspects of the
Las Vegas Wash is the relationship be-
tween average monthly waste water flows
in Las Vegas and the amount of water
measured at the U.S.G.S. Gauging Station
at North Shore Road at the lower end of
of the Wash. Figure 36 shows that
although the peak discharges to the Wash
(in terms of waste water flows) occur
during the summer months, the lowest
flows in the Wash also occur during that
time period. This is undoubtedly due to
the high rate of evapotranspiration in
the upper Wash. In terms of continued
maintenance of vegetation and water
conditions in the Wash, this means that
any future discharge programs related
to the project will require determination
of water requirements in the Wash on a
month-to-month basis and water releases
according to that schedule.
The reuse of waste water in Las Vegas
Valley will reduce the demands for with-
drawal on the Colorado River. Return
of acceptable quality water to the river
would go as a credit to Nevada's allot-
ment of 300, 000 acre-feet per year, thus
adding to the amount of this valuable
resource.
owned land. The long-term maintenance
of the Wash is also dependent on some
kind of public ownership of the Wash, be
it buying the land the Wash is located on
or acquiring a flow easement.
Flexibility in the system is one of the
features that should be a major considera-
tion in any proposed project. Waste water
demand will fluctuate considerably from
one month to the next and one season to
the next. Any excess water will be re-
leased to Las Vegas Wash. The pro-
jected in-valley irrigation for 1982 will
amount to 9.4 mgd; however, this amount
may never be used for that purpose.
Any amount not used will be discharged.
to Las Vegas Wash. With additional
In-Valley irrigation, more water is
expected to return to the Wash as
underflow from the alluvial fan.
Vegetation and Wildlife
One of the features of all the proposed
alternatives is the change in the point
of waste water discharge to the Wash.
Centralization of the City of Las Vegas,
Clark County Sanitation District and
Henderson Secondary Waste Water flows
for advanced waste water treatment will
eliminate existing discharges to the
Wash from the City of Las Vegas and
the Henderson Treatment Plant.
Water is not the only factor necessary
for the maintenance of Las Vegas Wash.
The majority of the Wash is on privately
The effects of the elimination of discharge
from the City of Las Vegas Plant will
have the greatest impact on (1) vegetation
205
-------
ESTIMATE OF ANNUAL FLOWS TO LAS
1.
2.
3.
4.
5.
6.
7.
8.
AND LAKE MEAD FOR THE
Source of Discharge
to Las Vegas Wash
City L.V. WWTP
Clark Co. San. Dist. WWTP
NPC - Sunrise Power Plant
NPC - Clark Power Plant
Nevada Rock & Sand near Sunrise
BMI Pond Seepage
Undescribed Sources
From Las Vegas Valley
TOTAL OF IDENTIFIABLE SOURCES
Less evaporation & transpiration
Computed discharge to Lake
YEARS 1
1971
mgd
20.99
7.90
0.20
0.94
0.50
3.87
7.11
2.95
44.46
-13.10*
31.36
VEGAS
971 TO
1972
mgd
22.00
10.00
0.20
0.70
0.50
3.87
7.11
2.95
47.33
-13.10*
34.23
WASH
1973
1973
mgd
27.60
9.00
0.20
0.70
-0-
6.50
3.6
4.20
51.8
-9.80
42.0
1
1
1
1
1
1
1
1
1
1
1
8
0*
*Includes 3. 3 MGD evapotranspiration below the geologic barrier.
Sources: NECON, 1971 and 1973; 1972 Environmental Assessment
206
-------
D
OJ
I
1
i I
Q
LU
Q
t/J
.:'
' 3
2
...
M
i-
MONTH
RELATIONSHIP OF AVERAGE DISCHARGES
TO LAS VEGAS WASH PER MONTH
(IDENTIFIABLE FLOWS) AND AVERAGE FLOWS
AT THE U.S.G.S. GAUGING STATION
AT NORTH SHORE ROAD FOR 1971
207
-------
composition, (2) the amount and location
of vegetative communities and (3) the
wildlife use and species composition as
a result of the floristic changes. Existing
discharges above the Clark County dis-
charge point, amount to approximately
27.8 mgd (City of Las Vegas Treatment
Plant and Sunrise Power Plant).
According to Bradley and Niles (1973),
the primary plant community above the
Clark County Sanitation Plant is the salt
cedar biotic community. With the re-
duced flows, the salt cedar community
is likely to change into more arid and
drought tolerant communities. Tolerant
plants such as those characteristic of
the mesquite or salt bush communities
may be the replacement community. The
total area to be impacted would amount
to approximately 400 acres. Historically,
this upper Wash area contained dense
areas of mesquite which were maintained,
in part, by the Las Vegas Springs which
flow to Las Vegas Creek, so it seems
likely that the mesquite community would
again become dominant unless management
measures are taken.
In the recent "Report to the Board of
County Commissioners" by the Las
Vegas Wash Development Community,
recommendations for educational and
recreational use of the area included
maintenance of the salt cedar forest in
the area of the Wash above the Clark
County Treatment Plant. In order to
accomplish this recommendation,
changes in the proposed discharge
regime will be necessary.
Any of the proposed methods would
reduce the impact on upper Wash
vegetation and wildlife.
In addition to vegetative changes above
the Clark County Treatment Plant as a
result of effluent discharge relocation,
vegetation downstream is also expected
to be altered. From the present until
1978 when the first phase of project
operations began, the amount of water
to be discharged to the Wash can be
expected to follow the general upward
trend as experienced in the past.
During the first two years of project
operation, brine from the desalination
plant proposed in Alternatives 7 and 10
may be discharged into the Las Vegas
City sewerage system. This will amount
to approximately 0.27 mgd of brine which
will add approximately 15, 500 Ibs. of salt
per day to the Wash. , The result in change
in TDS will affect those plant species of
the Wash which are intolerant to higher
salt levels. Consequently, there will be
a transformation of some vegetative types
with more salt tolerant species such as
pickleweed, salt cedar, desert salt bush
or four-winged salt bush. After the initial
two years of the pilot program, brine
will likely be disposed of by evaporation
either at Dry Lake or at permanent
evaporation ponds near the plant.
The more water released to the Wash,
the area and the vegetative species
composition are expected to change to
more shrub and woodland and marsh
vegetation types. In addition, the amount
of surface water will likely increase.
208
-------
This, in turn, will provide additional
habitat for water-dependent wildlife
species.
Beneficial reuse of AWT water, as in
Alternatives 7 and 10, will require a
reduction of discharges to the Wash as
these reuse programs are initiated.
This action would cause changes in
downstream biotic communities and a
reversion from moist to more arid
condition.
In order to minimize the effect of flow
reduction on Wash, vegetation and wild-
life, recommendations have been made
by Bradley and Niles-(l973) and the
Las Vegas Development Committee
(1974) to: 1) Establish a management
plan for the Wash to include such things
as a levee system, check dam, etc.;
2) Release of at least 19 mgd of water
during the critical summer months,
3 mgd during the winter and an annual
10 mgd; 3) A monitoring system in the
Wash to determine changes in biotic
communities as a result of changes in
discharge regime and to determine if
the above recommended releases are
adequate or if additional flows are
needed to maintain the Wash in a viable
state. In order to ensure the perpetua-
tion of Las Vegas Wash, these recom-
mendations should be implemented.
Eliminating all direct discharges but
allowing groundwater to continue flow-
ing, will have an unknown impact on
vegetation and wildlife. The quality of
the g.roundwater will be worse than that
of the present flows. Some areas may
slowly die and, unless they burn, will
remain as dead standing areas for many
years. A slow succession of salt cedar
will take place. If these areas are
cleared off or burned, during times of
heavy precipitation there will be no vege-
tation to hold the soil or catch water,
resulting in erosion of nutrient-rich
soil which then flows to Lake Mead.
The extent of the loss of vegetation and
wildlife is directly related to the reduc-
tion of recreational use. Las Vegas,
in its present environment, is not as
productive as it could be. With less
water than is now flowing in the Wash
and the management program, the rec-
reational value o( the Wash can be
enhanced.
The loss of marsh vegetation and habitat
would be a long term adverse impact.
Smaller wildlife such as amphibians
would probably be lost. Birds and
mammals of the lower Wash would be
displaced. It is doubtful that this por-
tion of the Wash is a major habitat area.
Dr. Bradley and Dr. Niles give insight
into the diversity and amount of use this
area supports. The major impact of
wildlife displacement will occur if sur-
rounding areas are at their carrying
capacity. If these areas, such as the
upper marsh are at carrying capacity,
then some wildlife will die, proportional
to the amount of habitat loss, or repro-
ductive rates could be reduced. The ef-
209
-------
feet on terrestrial birds will be of small
magnitude if salt cedar or mesquite are
growing in the Wash. The displacement
of wildlife is an adverse impact. If salt
cedar continues to grow and replace the
marsh vegetation, a beneficial impact
could result.
Another potential impact that could re-
sult from the elimination of direct dis-
charges to the lower marsh, is the im-
pact on Las Vegas Bay caused by storm
runoff. If the marsh vegetation dies,
and the ridge no longer holds the soil,
a large storm could cause silt to be
carried into Las Vegas Bay. This
addition of silt to the Bay would re-
sult in increased turbidity and nutrient
concentrations.
Impacts of No-Action
The alternative of no-action would per-
petuate the deteriorating water quality
conditions now apparent in Las Vegas
Bay. Municipal and industrial waste wa-
ters from the Las Vegas Valley along with
highly saline subsurface flows which are
discharged into Las Vegas Wash are the
main sources contributing to this degra-
dation. The principal effects of pollution
have been algal blooms in the Las Vegas
Bay of Lake Mead, and increases to the
salt load of the Colorado River. Fore-
seeably, no action would allow gradually
increasing, but uncontrolled amounts of
water to flow down Las Vegas Wash,
maintaining the riparian habitat.
It is a matter ol conjecture whether or not
the quality of water entering Lake Mead
might increase or decrease. However,
the' total nutrients in salt loading would
probably increase.
Algae blooms would continue producing
odors, and eventually harming fish in
the Bay. The increase flow would add
some small values to the power gene-
rated at Hoover Dam, but would con-
tinue losses to downstream water users
due to increased salt loading decreasing
the quality of water in the Lower Colo-
rado River System.
Ignoring the EPA enforcement action may
precipitate court action by the U.S. At-
torney General. A court order to cease
polluting Lake Mead might be issued.
The violators, including the City of Las
Vegas and the Clark County Sanitation
District, could be found guilty of con-
tempt of court if present discharges con-
tinue. Fines and prison sentences could
result. An injunction to prevent further
connections to sewage systems in Las
Vegas Valley could also be sought by the
Attorney General.
Failure to meet July 1973, Nevada Water
Quality Standards may result in the in-
ability to obtain approval for subdivisions
unless their sewage is treated tomeet
the standards. This is a result of a Ne-
vada State law effective July 1972, re-
quiring certification that sewage effluent
meets discharge standards. A development
could probably obtain approval if it were to
treat its own wastes.
210
-------
A No-Action alternative will not interfere
with the construction of the proposed Allen
Power Plant. Intentions of the Nevada
Power Company to continue negotiations
for the purchase of waste water for plant
cooling will not be impeded. Purchase of
secondary effluents from existing munici-
pal discharges in the Valley would be cap-
able of meeting cooling water demands.
Therefore construction of the proposed
power plant could proceed according to
plan.
SECONDARY IMPACTS
Sewerage facilities, as do most public
works projects, initiate and accommodate
community growth by subsidizing resource
development. This investment in waste
water treatment provides for population
growth by sizing the capacity of a treat-
ment facility so that a community infra-
structure, or inter dependency of service
and support subsystems will ultimately
develop to an equal population equiva-
lent. For example, services such as
police, schools, fire, electricity, water,
and roads will have to provide for the
population capacity accommodated within
the sewage treatment facility.
Therefore, the sizing of facilities can
create or hinder an urban capacity, which
in itself can be environmentally beneficial
or adverse. In the previous section on
Primary Impacts, many specific causes
and effects were identified. In Chapter 1,
a population base for the year 2000 was
established at 700, 000 in the Las Vegas
Valley. The accommodation of this pop-
ulation given the environmental constraints
identified in the INTRODUCTION, is more
dependent on planning and regulation of
development to delineate an adaptable
urban form but there is an ever growing
dependency on modern technology to
achieve and maintain the quality of life
for those future populations.
To the extent that the capital cost of
sewerage facilities is very high and
public grant assistance is used in con-
struction, the subsidizing of facilities
provides the community with the cap-
ability it would not necessarily have
within its own financial resources.
Hopefully the following discussion of
secondary impacts provides the reader
with a better understanding of such
implications.
Economic Implications
The project costs of the waste water
treatment system are expected to be
based on a cost sharing formula consist-
ing of a 75% contribution by the Federal
Government and a 25% contribution from
local governments. This is based on the
stipulation that the treatment system pro-
tects the natural environmental and the
overall long-term productivity of the
area.
Local funds will be raised by the sale of
revenue bonds. The bonds would be paid
back by increasing the cost of sewer
211
-------
service, water, or both. When the pro-
ject reclaims waste water to provide
a quality equal to that of domestic water,
it is proper to increase the cost to re-
flect the added cost of providing water.
This project will require the acquisition
of private land for a number of facilities.
These include lands for the waste water
collection system, In-Valley irrigation
pipelines and reservoirs, the sludge dis-
posal ponds, and whatever other facilities
depending upon what the selected alternative
projects will be. Cost of this land will
vary according to the site, however, since
many of the facilities are located in or
adjacent to residential and commercial
areas, the cost of acquisition of land,
right-of-ways and severance fees will
be substantial. These costs are contained
in the main body and appendices of the
applicant's facilities plan.
Construction and operation of the pollution
abatement facilities will provide part-
time and permanent jobs for contractors,
laborers, engineers and personnel to man
the new facilities. A significant portion
of their earnings would be spent in the Las
Vegas Valley.
Growth Accommodations
Nine of the 10 project alternatives (see
'no action1) and all four of the viable
alternatives enable growth by providing
waste water management facilities. Some
growth is going to take place in the Las
Vegas Valley, but how much growth and
the rate at which it occurs depend on what
the people of the Las Vegas Valley desire.
Through planning, regulation of develop-
ment activities, and the continued ap-
plication of modern technology, any ev-
entual urban form will have to be within
the environmental constraints of the Val-
ley. The responsibility for growth rests
with the County and local government
bodies. Utilities will continue to pro-
vide power, water, proper waste dis-
posal, and treatment if growth is to con-
tinue with a minimum of adverse impacts
and as long as means are available. This
requires planning by the utility agencies
so that pollution of the environment does
not take place.
Growth results in increased construction,
increased power demands, increased
transportation demands, increased sup-
port services demand.s, and increased
water demands. All of these increased
needs result in a greater commitment
of resources, a reduction of air quality,
and increased noise levels to perpetuate
the lifestyle as it is known to exist.
Alternative 9 (the no-action alternative)
would have the practical effect of pre-
venting growth. However, no action does
not resolve the continuing water quality
degradation of Las Vegas Bay and there-
fore is not a viable strategy for regula-
ting or stopping growth. Due to the nature
of the study area, tourist visitations are
expected to increase, limited by hotel
capacities and available service emp-
loyees. The result would be a slowed
212
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rate of increase in power, transportation,
and water demands. Construction and
growth would be limited to those develop-
ments providing their own waste water
disposal to be able to meet water quality
standards. Unless planned, the regu-
lation of growth can be economically de-
trimental, yet environmentally beneficial.
tenance of air quality, the maintenance of
water quality, and the availability of future
potable water in the Las Vegas Valley.
The latter questions are considered in suc-
ceeding portions of this impact section.
The question of the relationship between
the Allen Power facility and the availa-
bility of AWT is considered next.
The consolidation, expansion and upgrad-
ing of waste water treatment can be viewed
as accommodating further population and
economic growth in the Las Vegas Valley
rather than inducing development. The
first modular phase of the AWT plant would
begin operation in 1978 and would have a
capacity of 90 mgd. With the projected
maximum day waste water production of
85. 2 mgd by 1980, the initial AWT plant
will have a reserve capacity of 4. 8 mgd.
The second stage of AWT would be on line
by 1982 and would provide for a maximum
AWT capacity of 112.5 mgd (90 mgd +
22.5 mgd). This capacity will be sufficient
until 1990. The construction of the third
AWT stage will provide an additional
22. 5 mgd capacity which would be suf-
ficient to treat the waste water flows
until year 2000.
A major question to consider when eval-
uating the role of the waste water treat-
ment system as a growth inducing factor,
is whether or not the projected population
figures for the area appear reasonable
and particularly if the area can adequately
support that population environmentally.
For the Las Vegas region, the environ-
mental constraints that might well dictate
future population growth may be the main-
The Environmental Impacts of the
Allen Power Generating Facility
Regardless of the alternative selected,
the Allen Power Plant may or may not
be constructed. This plant is dependent
upon a water supply of 36 to 38 mgd.
According to the Nevada Power Company,
the only source of cooling water for the
plant is effluent from Las Vegas Valley.
Although a separate impact statement is
required before the plant can be built, the
impacts are considered here on general
terms.
The Allen Power Plant will provide power
for use by man for light, heat, and energy
for a variety of uses. Air conditioning
currently consumes over half of the power
used in Las Vegas, and enables life in
the desert on a comfortable basis. Power
is also required for pumping and treating
waste water, especially in desalination
processes. The various electric con-
sumptive rates for the viable alternatives
are indicated in Table 24. Nevada Power
Company's projections show that 70% of
the power will be used by the customers
of Southern California Edison Company
213
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and 30% will go to the customers of
Nevada Power Company from 1977 to
1983.
From 1984 to 1990, there will be a 50-50
benefit split, and between 1990 and 1994,
Nevada customers will regain 100% of the
power. The plant will enable growth in
electrical consumption by providing power
for increased populations.
Through sale of power to Southern Cali-
fornia Edison, it can be expected that
demand will justify development of re-
placement generation facilities to the
SCE service area once the Allen plant
output is no longer available. There-
fore, the Allen Power Plant will ac-
commodate continued growth and con-
sumptive use of power in the Southern
California service area.
in present air quality. Wind direction
data for Las Vegas (HEW, June 1970)
indicated that this could occur perhaps
10% of the time in winter and perhaps
6% of the time in summer. No clima-
tological work has been done to verify
wind directions at the plant site, and
therefore these projections are specu-
lative.
Plant emissions will occasionally be
carried by wind into the Desert Bighorn
Sheep refuge presently being considered
by Congress as a part of the National
Wilderness Preservation System. Desert
Bighorn Sheep are a fragile species for
which hunting is restricted by law. The
percentage of time that winds will blow
in this direction is unknown, and the
effects are unknown, although the presence
of man interferes with the sheeps1 normal
behavior.
The plant will discharge large quantities
of waste gases into the atmosphere. Ope-
rating at 80% of capacity, the plant will
burn about 16, 000 tons of coal per day,
producing 34. 5 tons of sulfur dioxide
(SO2), 150 tons of nitrogen oxides (NOX)»
14.4 tons of particulate matter, and un-
known quantities of other gases. Quanti-
ties are based on maximum allowable
emissions under Clark County and EPA
Standards in the assumption that these
standards can be met. Gas emissions
may be confined in Dry Lake Valley by
inversion layers, or may be conveyed
by winds to the populated areas of Las
Vegas Valley on occasion, causing a
decrease in visibility and a degradation
Plant emissions may be reduced through
sophisticated control devices. The
efficiency of these has been questioned
in conjunction with existing power plants,
particularly the Mohave plant in Clark
County. Complete elimination of the waste
gases would occur if a nuclear plant were
constructed instead. However, there is
no need to expand on the environmental
risks of such a trade-off.
The Allen Power Plant will require a
long-term commitment of water for
cooling. When water is used in the
generation of power, it is by definition
a beneficial use. If that water could be
214
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put to a more beneficial use, and the
commitment of its use for power gene-
ration prevents that, then an adverse im-
pact results. Nuclear power also re-
quires cooling water usually in increased
amounts.
The agreement between the Nevada Power
Company, Clark County, and the City of
Las Vegas provides that in the event
AWT effluent is not available by 1979,
the Nevada Power Company may elect
to purchase secondary effluent from the
City and District,
Operation of the Plant will require the
burning of 5. 5 million tons of coal per
year. The Nevada Power Company will
purchase coal mined for the specific
purpose of supplying the Allen Power
Facility. Strip-mined coal will be trans-
ported by a slurry pipeline some 175 miles
south to Las Vegas. Coal field locations
in Utah are identified in Figure 37. At
the time of the writing of the Impact State-
ment for the Allen Power Facility, EPA
requests the priviledge of commenting on
the potential impact to water quality re-
sources that may result from the mining
operation. Of further interest is the fact
that an additional coal-fired power facility
located in St. George, Utah will supply
Las Vegas with an additional 500 megawatts
and is scheduled for first unit completion
in 1978. Coal is a limited irreplaceable
resource. Commitment of such a resource
reduces reserves for future generations.
The Power Plant and associated trans-
mission lines will change the desert
scenery and add noise.
Operation of the Plant provides solid
wastes which must be disposed of. Based
on Southern Nevada Power Company state-
ments that all wastes will be reduced to
solid form, the impacts of disposal are
related'to the use of the wastes. If it
is used beneficially for man, it would be
considered a beneficial impact. If it were
piled on mounds in the desert, it would con-
stitute an adverse impact.
Implications on Regional Air Quality
The major air pollution sources con-
sidered for the proposed project are
construction activities, motor vehicles,.
and the advanced waste treatment plant.
A discussion of the impact on air quality
from construction activities and emissions
from the advanced waste treatment plant
were presented in the preceding section
of this chapter. The following discussion
considers the impact of the proposed pro-
ject on a broader frame of regional air
quality.
Motor vehicle emissions immediately re-
lated to the AWT Plant are induced by
the vehicle volumes generated by operat-
ing and maintenance personnel. It is
assumed that neither facility will con-
stitute a significant tourist attraction.
It is estimated that the AWT Plant will
require from 25 to 30 men per shift.
Thus, a maximum of about 40 spaces
for parking will have to be provided.
The emissions associated with this
number of parking spaces would be
negligible, 'in addition, the existing
215
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PROJECTED AWT PLANT
RESERVE CAPACITY
Year
1980
1990
2000
AWT Cap.
(MGD)
90
112.5
135
Range of Excess or
Deficit Capacity
+ 9% to - 0. 4%
+ 5.6% to - 10.5%
+ 3.9% to - 16.4%
+ indicates excess capacity
- indicates deficit capacity
State of Nevada Air Pollution Control Re-
gulations and the proposed amendments
to Clark County's Regulations specify
a cut-off of 500 parking spaces before a
review is required
Provisions of AWT for waste water from
Las Vegas Valley will permit: 1) com-
pliance with water quality standards,
2) reduction of salt loads to the Colo-
rado River and, 3) beneficial reuse of
waste water to enhance the overall water
resources of the area. As a corollary
to these benefits, a long-term impact on
the air quality of the region will occur
from the growth accommodated by the
proposed project. Projections of future
air quality as affected by any growth
accommodated by the proposed project
would be of questionable accuracy since
the basic analytic data has yet to be de-
veloped.
Additional meterological data for the
Region is specifically patterned for the
conversion of source emissions to air
quality concentrations. This data is now
being developed. Knowledge on wind
patterns, vertical temperature structure,
and inversion incidence will be.monitored,
As noted in Chapter 1, these data are
being developed. Another variable in
the long-term projection of regional air
quality, is the actual population growth
versus the projected growth used in
sizing the project facilities. Based on
the projected maximum day waste water
flows for Las Vegas Valley, the following
Table has been developed to show the
range of reserve or deficit capacity of
the AWT Plant as presently planned. In
addition, any air quality degradation as
a result of the proposed Allen Power
Plant would be a direct result of the
provisions of waste water facilities.
From the above Table, it can be seen
that, depending on actual population
growth, there may be no excess plant
217
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capacity at some time in the future.
However, the time spans considered
over the life of the Project will permit
interim actions to be responsive to:
1) actual needs, 2) changing regulations,
and, 3) advances in technology. The
potential impact on regional air quality
in quantified terms is problematic.
Water Quality Implications
Since all of the viable alternatives,
in part, provide for the AWT of waste
water and return in part to Las Vegas
Wash, varying solutions will have vary-
ing consequences on water quality. All
of these alternatives will meet the Ne-
vada State and Federal Water Quality
Standards and the salinity reduction ob-
jectives of the Colorado River Basin
Salinity Control Act, as adopted. No
action would result in the further de-
gradation of Las Vegas Bay.
Any decrease in algal populations re-
quiting from phosphorus decreases may
nave a beneficial impact on the quality
of recreation in the Las Vegas area.
Maintenance on boats moored in the area
should decrease as a result of decreases
"\ algal growth. In addition, the noxious
odors produced from algal blooms and
die-off in the Bay should be reduced.
Ihe benefits of reduced algal blooms may
also be realized by consumers of water
supphed through the Southern Nevada
Water Project.
Some shifting in the distribution of biota
may occur as result of any changes in
algal populations. According to Deacon
and Tews, thread fin shad, characteris-
tically concentrate at the thermocline
of Las Vegas Bay, probably due to the
presence of large amounts of organic
debris from which they feed. Much of
this organic debris is provided by flows
from the Wash and from algal production.
Reduction and dispersion of organic mat-
ter and algae may cause these fish to
eventually redistribute, however, this
appears problematic. This may conse-
quently result in a shift in the carniver-
ous game fish which depend on thread
fin shad populations as a source of food.
All alternatives will provide for an
In-Valley irrigation system which will
increase the amount of constitutents from
diffuse sources reaching Las Vegas Wash
and ultimately Las Vegas Bay.
Due to the fact that salt contributions to
the Colorado River Systems are an en-
vironmental constraint, any removal of
salt from any proposed discharge is
considered beneficial. The concentra-
tion and loading of salt in the Wash,
discharges vary with each alternative.
Alternative No. 2 would desalinate ef-
fluent prior to discharge, while Alter-
native Nos. 7 and 10 provide for a pilot
desalination plant program. Alternatives
No 2 and 7 would export the majority of
effluent out of the Basin (to Dry Lake)
and only have a greenbelt maintenance
218
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discharge to the Wash. 'Alternatives
7 and 10 provide for the sale of 36-38
mgd of AWT effluent for beneficial re-
use by a proposed power plant, prior to
its disposal outside of the Basin (Dry
Lake). Alternative No. 3 has no program
of export, therefore would contribute
increased loadings of salt due to in-
creased AWT flows over and above
those of the other alternatives.
If increased population growth and sub-
sequent urbanization continue, increased
surface flows and flood flows can be ex-
pected to eventually reach Las Vegas
Wash and ultimately Las Vegas Bay.
As land is converted from its natural
condition to housing subdivisions, com-
mercial centers, roads and recreational
areas, soil systems are disturbed and
impervious surfaces are imposed on the
natural terrain. Accelerated surface
run-off from impervious surfaces in-
creases the erosion potential down-
stream. The process of erosion normally
results in increased sedimentation and
siltation of the surface water streams.
(See Figure 9). The Environmental
Protection Agency, in a study entitled
Control of Sediments Resulting from
Highway Construction and Land De-
velopment , estimated that sediments
from urbanizing areas varies from
1, 000 to 100, 000 tons per square mile
per year, while sediments from ur-
banized areas varies from 200 to 500
tons per square mile per year. Sedi-
ments deposited in lakes and streams
may decrease water clarity and inter-
fere with biological life cycles which
depend on clear bottom conditions.
Soil sediments also contain various
nutrients which may accelerate the pro-
cess of eutropication in lakes, and in-
crease the biological productivity of
streams.
The impact of road construction, one
of the first manifestations of urbaniz-
ation, can hardly be over-emphasized.
Roadway run-off often contains chemi-
cal constituents and solid waste mate-
rials that may seriously degrade water
quality and surface water regimes.
Such constituents include asbestos from
automobile brake linings, oils and
greases, rubber, ferrocyanide, sodium
ferrocyanide, chromate and phosphate..
These roadway pollutants may also cause
serious damage to vegetative communities
adjacent to the roadways.
Water Quantity Impacts
Each viable alternative and the No-Action
alternative will provide for different
volumes of water being released down
Las Vegas Wash, as well as for other
uses. Alternative 3 will result in all
water receiving advanced waste treat-
ment prior to its discharge to Las Vegas
Wash and diversion downstream for in-
valley irrigation. Alternatives Nos. 7
and 10 provide for other beneficial uses
after advanced waste treatment either
inside the Valley and export for disposal
(with a pipeline to tap secondary effluent)
for beneficial reuse (7) or export for bene-
ficial reuse as well as recharge to Las
Vegas Wash (10). No action would still
result in the continuation of nutrient rich
discharges to the Wash from the existing
219
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secondary treated municipal discharges.
will have a beneficial and adverse im-
pact on fish and wildlife.
With the different volumes of AWT water
being released down the Wash, it can be
expected that Wash vegetation will be im-
pacted in terms of its distribution, den-
sity, and quality; and concurrently the
distribution and density of wildlife de-
pendent on that cover. As was mentioned
in Primary Impacts, flows down Las
Vegas Wash would be diverted prior to
entering Lake Mead for beneficial reuse,
thereby eliminating this augmentation flow.
Certain vegetative habitats may be im-
pacted by the loss of nutrients more than
by the change in available flow. Flow
variances that would be experienced
with the various alternatives would not
appreciably impact flow in the Lower
Colorado River, since quality is a more
significant constraint; however, the impact
of particular constituent loadings is dir-
ectly related to the volume and quality of
the waters receiving the discharge.
Fish and Wildlife Impacts
As has already been discussed, the
accommodation of continued urbanization
Increased power generation by the Allen
Power Facilities may result in carrying
air borne pollutants into the Desert Big
Horn Sheep Refuge, thereby resulting in
impacts of unknown consequence and mag-
nitude.
Reduction in the nutrient concentration of
flows reaching Las Vegas Bay may result
in impacting the treadfin shad which de-
pend on algae populations for food, and con-
sequently on any predators of the treadfin
shad.
With the change in density, distribution,
and quality of vegetative habitats in and ad-
jacent to the Wash, various wildlife species
will be affected. Birds, water fowl,
mammals, reptiles and invertebrates that
are impacted will not be irreperably im-
pacted due to the abundant replacement
habitat, whether Wash related or desert,
to mitigate such impact. However,
brackish water habitats may decline.
220
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It is anticipated that all of the viable al-
ternatives will have impacts of a similar
nature only varying in magnitude from
alternative to alternative. To prepare the
reader, the following discussion will not be
site-specific nor will the no-action al-
ternative be considered since no action
would be the perpetuation of an already
recognized adverse environmental dilem-
ma. The generic impact common to each
alternative along with the means to miti-
gate its impact will be considered.
PRIMARY IMPACTS
Since the proposed alternatives are a
long-term community investment to im-
prove an existing adverse condition, the
removal of property from the tax rolls
to accomodate facilities and the increased
cost of sewer service are a given con-
sequence of such an investment. How-
ever, since 75% of the initial cost for
planning, design and construction is re-
imbursable by the Federal Government,
the severity of that initial capital in-
vestment is mitigated.
The normal construction-related impacts
of increased noise, dust, soil disturbance,
disruption of traffic flow are generally un-
avoidable. They can be mitigated by con-
struction specifications delineating dust
suppression measures, construction
during daylight hours, minimizing the
movement of earth to accomodate struc-
tures, and keeping construction-related
equipment and vehicles off or from cros-
sing traffic-bearing surface roads.
The removal of vegetation ami i.hn ex-
cavation, removal, and compaction of
soil are generic to construction of the
collection system, AWT plant, and ex-
port lines. Again these can be mini-
mized through construction specifications
directing the contractor to limit the con-
struction area to the smallest possible
area. Restoration of areas where re-
moval of vegetation was necessary or
where soil disturbance occurred will be
the responsibility of the contractor.
In addition, conveyance line alignments
that do not disturb natural habitats which
support abundant vegetative cover and
wildlife should bo encouraged. Some
erosion will occur with a potential for
increased nutrient-bearing silts reach-
ing Las Vegas Wash and eventually Las
Vegas P^ay.
221
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The actual operation of facilities after
construction will result in additional
noise from pumps and the treatment plant.
This can be mitigated by housing of these
facilities and baffling or insulating them
for sound.
Deposition of waste sludges and brines
will result in some loss of land com-
mitted to these purposes. Sludges will be
disposed of at a land fill site classified
to accept these wastes.
Salt accumulation in the Colorado River
system is an adverse impact whose con-
trol is dependent on engineering means
to initially control the magnitude which
would vary from alternative to alternative.
Alternative 3 would result in greater salt
loadings through increased discharge
volumes of effluent reaching Las Vegas
Bay while Alternatives 2, 7 and 10 would
export and/or beneficially reuse waste
water, but would return smaller flows
to Las Vegas Wash. Salt accumulation
within a waste water management system
has recognized environmental and ec-
onomic costs.
Beneficial reuse of waste water for in-
valley irrigation will create new diffuse
sources of water pollution reaching Las
Vegas Wash. However, the benefits de-
rived would greatly outweigh the mini-
mal water quality detriments anticipated.
The disposal of any effluent will be gov-
erned by where the costs are incurred.
Alternative 2's complete treatment with
maintenance disposal to the Wash poten-
tially provides the highest water quality
benefit to the receiving water. Alter-
native 3's AWT with no export and return
to Lake Mead, has the highest receiving
water quality impact, providing a greater
volume of effluent resulting in greater
salt loadings than that of Alternatives
2, 7, or 10. Alternative 10 meets the
water quality standards of Lake Mead
and provides for beneficial reuse and
a reduced salt contribution to that of
3. Since Alternative 7 provides only
AWT of flows necessary to maintain the
existing riparian recreational environ-
ment of Las Vegas Wash and not violate
Federal-State standards in Las Vegas
Bay, the return flow benefits from
this alternative would be minimal.
Changes in the environment at Dry Lake,
such as increased salinity concentrations
at Dry Lake and surrounding wells near
the site; increased temperature and
humidity near Dry Lake; and loss to the
present use of Dry Lake all characterize
the nature of export called for in Alter-
native 7.
All alternatives will require electrical
power in varying magnitude. Refer to
Table 24.
SECONDARY IMPACT
The secondary impacts as discussed in
the previous chapter cannot be avoided
altogether. To a great extent those im-
pacts that would specifically pertain to
the accommodation of a potential future
population (changes in land use, expan-
sion in public services, air quality de-
222
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gradation, increased resource exploi-
tation, etc.) are unavoidable. However,
the magnitude of those impacts are sub-
ject to some control, either through
technological, statutory, or regulatory
means. Nonetheless, growth is anti-
cipated to create these impacts which
are unavoidable.
The various viable alternatives allow
for varying volumes of water return-
ing to Las Vegas Bay via Las Vegas
Wash. Dependent on these releases,
the increase in water volume will
change the width of the stream and
velocity of flow. These changes could
result in changes to the vegetative com-
position of the Wash. Another conside-
ration would be the loss or displacement
of wildlife depending on that vegetative
cover for food or shelter. Since each
alternative will result in this type of
impact, it is unavoidable yet within miti-
gation capabilities of the applicant to re-
duce the magnitude of any extreme impact.
In addition, any waste of water in this
watershort environment is ah adverse
impact on the human environment which
is not in the best interest of sound water
management. All viable alternatives
to some degree provide for beneficial
reuse of the AWT water, with Alternative
10 identifying several reuse programs
for AWT water beyond any identified
in the other viable alternatives.
Any increase in the amount of high quality
effluent discharges to Las Vegas Wash
will offset any existing adverse water
quality problem in Las Vegas Bay. How-
ever, as was mentioned in the section on
secondary impacts in Chapter 3 with the
improvement in water quality, loss in
algae populations may result in a re-
duction or displacement of threadfin shad
and their attendant predators, but to what
extent is unknown. Also vegetation which
is dependent on a certain concentration
of nutrients being present in Las Vegas
Wash flows to maintain certain vegetative
habitat is a concern. Due to the impend-
ing enforcement action if nutrients are
not largely eliminated from the waste
water discharged, this loss is the trade-
off for attainment of clean water objec-
tives. Worthy of consideration would
be a scheduled release of secondary ef-
fluent that could be discharged to the
Wash to mitigate this loss. This re-
lease arrangement would require a new
permit for the existing secondary dis-
chargers delineating a schedule of
allowable quality ranges within which
such discharges could be made.
With the construction of Alternative 7 or
10 the supply of cooling water to the pro-
posed Allen Power Plant raises some
long-term environmental questions which
will be explored in the following chapters.
Any salinity contributions that continue to
increase TDS levels in the receiving
water require a greater attention to con-
trolling source contributions. Another
consideration is the relationship of TDS
concentration within a certain volume of
flow. In other words, dilution capability
in any case would be a water quality plus;
Alternatives 3 and 10 provide the largest
amount of dilution capability. Alternative
2 has the highest degree of desalination
223
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but only a maintenance discharge to the
Wash of minimal proportion. Alternative
3 would result in the greatest volume of
AWT discharge to the Wash and hence the
highest dilution capability. Alternative
10 provides for pilot desalination and
pilot ground-water augmentation with a
more generous Wash maintenance pro-
gram than 2 or 7. Eventually the aug-
mentation of ground water may increase
as feasibility dictates and as consumption
increases. Alternative 7 would return
the least volume of water, but would re-
sult in export that would remove volumes
of salt from the Colorado River system
along with the exported effluent. It is
expected that with the removal of in-
dustrial contributions to the Wash, salts
(TDS) would be stabilized in their con-
centration, and over a period of time
would eventually be reduced in Las
Vegas Bay.
The means by which salt loading is con-
trolled is technologically moot, with
economic and environmental balance
suggesting 2, 3, 7 and 10 to be a toss
up, other economic and environmental
concerns would leave Alternative 2 as too
expensive, Alternative 7 as being less
beneficial to other downstream uses, and
3 and 10 worthy of further consideration.
224
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-------
In this chapter of the environmental
impact statement, the short-term ob-
jective of improving the community
capability to meet Federal-State
standards in order to abate pollution
in Lake Mead, versus the maintenance
and enhancement of long-term com-
munity productivity is explored.
Through the supplementing of County
financial resources by Federal grant
assistance, this combined investment
provides the Valley Community with a
new lease to expand urban growth and
to continue the quality of life.
The short-term technological mastery
of the very environmental constraints
that limit man's long-term adaptability
to the desert environment is made possi-
ble but with some acknowledged environ-
mental detriments. These detriments
are explored further in Chapter 6. The
facilities' consumption of electrical power,
use of materials in its construction, and
the loss of undeveloped lands are recog-
nized expenditures worth the investment
when weighed against the benefits re-
turned. The increased capacity to treat
and dispose of waste waters within
Federal-State water quality standards
prior to their return to the Colorado
River; the crediting of return flows to
compensate for withdrawals of surface
water allocations and; the beneficial
reuse of other flows for in-valley irriga-
tion, or as identified in Alternatives 7
and 10 for cooling water in the proposed
Allen Power Plant of the Nevada Power
Company, add up to short-term actions
of long-term magnitude. Guaranteed
water quality maintenance, the means
to augmenting potable water withdrawals
from the Colorado River, and the accom-
modation of additional electrical power
generation, sets into motion for the
communities of Las Vegas Valley the
necessary measures to solidify a mul-
tiplicity of future planning scenarios.
No doubt the allowance for continued de-
gradation of downstream water supplies
by waste water flows would be severely
damaging to the long-term productivity
and maintenance of man's presence in
the Lower Colorado River Basin. How-
ever, sustaining man's productivity in an
extreme desert clime is a long-term
commitment of resource exploitation
that goes far beyond the Valley community
into areas yet untouched by man's heavy
226
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hand. The conversion of .raw resources
into fuels and hardware grant technologi-
cal reprieves to sustaining a lifestyle
where the balance between resources
availability and resource consumption
is finite. Therefore, any decision re-
garding a major short-term monetary
investment is an investment in the con-
tinued maintenance of a consumptive trend
which will have to escalate to sustain the
long-term community productivity.
EPA has yet to assess how demand for
power in the Southern California Edison
service area would be affected with this
diminishing supply arrangement. Nor
what pressures would be brought to
supply new power generation sources and
at what environmental cost. Also unas-
sessed is the economic effect when mar-
ginal power supplied at a reduced cost
creates a demand related to a surplus
supply in the Los Angeles area.
It goes without saying that the present
means of discharging waste water to the
environment can be considered an unac-
ceptable short-term use that, with proper
waste water treatment, can become a
long-term, benefit to the environment.
In terms previously set forth in Chap-
ter 3, the maintenance and enhancement
of wildlife in Las Vegas Wash and the
provision of waste water for beneficial
reuse can definitely be a long-term de-
posit which will appreciate for genera-
tions to come.
As of this writing, the City of Las Vegas
and Clark County have entered an agree-
ment with the Nevada Power Company
for the sale of AWT water for use in the
proposed Allen Power Plant. Waste
water is the only source of cooling water
available to the plant. The plant is ex-
pected to be in operation within the next
six years, but will not be generating
power initially for the exclusive use of
In-Valley communities, and will be trans-
mitting major portions of its output at a
declining rate to the Southern California
Edison service area of Los Angeles
through 1994.
Since growth is so intricately linked
with any waste water management scheme
within the Valley, considerations of its
contribution to air quality made by in-
creased populations were identified in
Chapter 1. A 1973 emissions inventory
found that State Ambient Air Quality
Standards were exceeded for photochemi-
cal oxidants and particulates when moni-
tored in downtown Las Vegas. Similar
data for CO and HC were unavailable.
It is hoped that the current emissions'
inventory update will provide additional
air quality information on concentrations
of CO and oxidants to facilitate their
translation into remedial actions.
Therefore, the information relating
to the long-term air quality dynamics
resulting from increased population is
still under development and any popula-
tion increases may complicate the clean-
up effort.
Emissions from the Allen Power Plant
will mostly be confined to the Dry Lake
Valley by inversion layers, or conveyed
by winds to the populated areas of Las
Vegas Valley on occasion, causing a
227
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decreased visibility and degradation of
the present air quality. Since wind data
is still being developed, how often this
will occur and for what duration is un-
known. What long-term impact degra-
dation of the exterior air quality will
have on a tourist industry mainly oriented
to recreating indoors is undeterminable.
The long-term impacts of strip mining of
coal in Utah and its proposed conveyance
to the Allen Power Plant site by a pipe-
line as a slurry, go unaccessed since
waste water resources development
directly accommodates such activities.
However, these questions no doubt will
be addressed in any environmental im-
pact reports prepared prior to that
project initiation by the Power Company.
It is the opinion of the Environmental
Protection Agency that the short-term
uses of the environment resulting from
the decision to construct waste water
facilities will have a profound effect on
the growth capability of the Las Vegas
Valley communities, while improving
and maintaining the water quality of
Lake Mead. However, of the alternatives
considered as viable, only Alternative 3
does not provide for AWT export to the
Allen Power facility and its yet unknown
attendant long-term secondary impacts.
The unknown extent to which the configura-
tion of urbanization will play on the main-
tenance of air quality is dependent upon
strategies implemented and maintenance
measures instituted by this Agency and
its state and local counterparts. These
strategies hopefully will bring about a
long-term resolution of many of the re-
cognized air quality problems.
228
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The commitment of any resources to the
implementation of a long-term, waste
water resource management and develop-
ment program obligates the immediate
community to an upwardly spiraling course
of expenditure and consumption. This
commitment implicates a network of
communities from which raw resources
will be drawn, investments of capital
and manpower made, to convert these
raw resources into products for con-
sumption* Foreseeably, all of this
activity will result in an escalation in
the expenditure of energy.
Since it is anticipated that no matter what
viable alternative is selected, the same
projected base population will occur, this
discussion will focus on the irreversible
and irretrievable events that will occur
as a result of this waste water resource
development project.
The conversion of raw sewage effluent to
a marginally useable resource (secon-
dary treatment) and then into a high
quality, highly usable resource (AWT)
is the establishment of that AWT resource
as the integral component in the mainte-
nance of an ecological machine where
the continued use of water by man is
essential to that machine's existence.
The establishment of such a machine is
not only an economic asset to the com-
munity, but with a guaranteed volume of
flow and quality returning to the Colorado
River System, water quality in the receiv-
ing waters will improve. Wildlife and
vegetative habitats will proliferate pro-
viding greater recreational opportunities.
As long as the quality requirements for
each habitat are met and maintained,
the irreversibility and irretrievability
of these flows is established. Commu-
nity water consumption may emphasize
a heavy dependence on the insurance
provided by the return flow credit
arrangement as a guarantee against
overdraft of In-Valley resources. The
successful banking of AWT waters in
the groundwateraquifer may be of equal
importance. Both arrangements may es-
tablish an irreversible and irretrievable
commitment of resources to future con-
sumptive patterns.
The commitment of money to construct
facilities, and the materials and man-
power committed to that end are irrever-
sible and irretrievable. The commitment
of land for facilities is irreversible and
230
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irretrievable, unless in the future the
location and means of waste water man-
agement are changed, then the return
of the land to its former appearance and
use would be possible.
Another facet of the Irreversibility and
irretrievability of resource consumption
arrangements, especially those that in-
volved a dependency on water, is the sale
of water for cooling the proposed Allen
Power Plant. This arrangement may
result in maintenance of an upward con-
sumption of water in order to maintain
the power plant so that an upward con-
sumption of electricity can continue.
This arrangement may be of questionable
benefit.
As identified in Table 25, revenues re-
turned from the sale of AWT to the Allen
Power Plant per million gallons treated
are shown. Of interest is the fact that
Alternative 7, when examined over the
long-term repayment period, results in
annual revenues of $30 per million gallons
treated. However, it costs the service
area consumer from $339 to $467 to
treat that same million gallons. With
Alternative 10, returns from direct
annual revenues from sale of cooling
water would only be $116 per million
gallons treated against it, costing the
service area consumer from $384 to
$434 to treat. With Alternative 3, no
AWT reclamation for the power plant
is involved and would result in greater
volumes of water being discharged
beyond the volume flows needed to
maintain water quality standards in
Las Vegas Bay and the Wash habitat.
However, the volume of TDS in the
Alternative 3 discharge may jeopardize
the attainment of the loads proposed
by EPA. Alternative 2 would produce
an effluent of a quality higher than the
quality of the receiving water and com-
parable to that of U.S. drinking water
standards, but at an enormous expense,
too prohibitive for any feasible consid-
eration.
However, if, with any of the Alternatives
the cost of treatment to continue supply-
ing the water to the power plant can be
avoided, it would seem more economic
to sell the power plant secondary efflu-
ent, with the necessary treatment being
done at the power facility. In fact,
with the power plant tapping 38 mgd
in secondary effluent, the ultimate size
of the AWT plants for any of the Alter-
natives could be smaller, and therefore
a greater capital cost to the Federal
Government and the applicant would be
avoided. Another consideration is that
the cost of treatment hardware would be
passed on by the Power Company to the
consumer if the Power Company had to
treat cooling waters prior to use. How-
ever, this consumer cost would be miti
gated by the consumers in Los Angeles.
The irreversibility of an investment in
hardware, especially when that hardware
has to do with water quality or supply in
this water quality and quantity short re-
gion, is an expensive one. Therefore,
it would seem in the best interests of
all parties concerned to construct a pro-
231
-------
ject that would treat and dispose of waste
water in the most economic means. If a
sizedown of the ultimate treatment faci-
lity is possible, as previously mentioned,
further consideration of the economics
of AWT capacity vs. Power Company
treatment is necessary.
The air quality implications from urban
growth of any oversizing of facilities or
a combination of electrical power genera-
tion will result in the degradation of that
air quality resource. Such degradation
is irreversible and irretrievable if main-
tenance of air quality standards through
regulatory or technical strategies is in-
capable of mitigating any of the degrada-
tion that occurs.
232
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ts
-------
In consideration of all documents sub-
mitted by the Board of County Commis-
sioners, the Environmental Protection
Agency agrees that Alternative 10 is the
alternative achieving the project objec-
tives and the alternative which is consis-
tent with the determination of the local
populace. Throughout this impact state-
ment, several questions have been raised
with regard to attainment and maintenance
of water quality and air quality standards.
Since this statement was written to eva-
luate a planning document, information is
still being developed to perfect decisions
as this "facilities plan" evolves.
Therefore, the following discussion will
serve to highlight certain outstanding con-
cerns that are within EPA's regulatory
authority. Recognizably, many of these
decisions may impact the proposed pro-
gram of reclamation/reuse, AWT effluent
export for power plant cooling. However,
until further information concerning this
proposal becomes available, EPA is unable
to evaluate the full environmental bearing
of this proposed power facility. There -
f°re, the Agency will reserve judgement
until such opportunities are afforded
us. Some of these opportunities are
identified below.
This Agency recognizes that there is a
water quality advantage in reducing the
introduction of dissolved solids (salts)
along with the other pollutants discharged
to the Colorado River system; however,
this does not preclude controlling in-
creased solids contributions at their
source. It is for this very reason that
a salinity investigation specified by
EPA in a letter of May 3, 1974 to the
Waste-water Management Agency
be initiated by the applicant to:
A. Identify and quantify all addition
of dissolved salts into the sewer-
age systems.
B. Recommend methods for reducing
and where practicable eliminating
the salts.
C. Recommend a control program includ-
ing ordinances where practicable.
D. Determine the salinity values of the
incoming secondary effluent from
Clark County Sanitation District
and the City of Las Vegas1 treat-
ment plant to the advanced waste-
water treatment plant if all the
recommended corrections are
instituted.
234
-------
Conceivably export, as would be achieved
by the applicant's proposed method of
reclamation/reuse would contribute to
the attainment of an acceptable dissolved
solids loading limitation. However,
removing water from the Colorado River
system will impact downstream water
quality. Therefore, the results of the
salinity source investigation may provide
Clark County with a better understanding
of how to control salts prior to their entry
into the waste-water system. With this
knowledge, and with this Agency's co-
operation with the Colorado River Basin
Salinity Control Forum, better strategies
for benefiting downstream water quality
in the Colorado and the Las Vegas Valley's
contribution to that end, can be realized.
This Agency requests further exami-
nation of the sale of secondary effluent over
the sale of AWT effluent to the proposed
power facility, in the event that opportu-
nity occurs. Foreseeably if secondary
effluent is diverted from the AWT collec-
tion system prior to its delivery to the
AWT facility, this arrangement would not
necessitate extensive expansion of AWT
facilities to meet 1980 and 1990 AWT
needs. Therefore a substantial capital
investment, which is now forecasted at
$22,200,000 (July 1974 dollars) would
not be necessary. Revenues from sale
of secondary effluent would still be ob-
tainable, even though they may not be
as high as those possible with AWT.
Therefore, EPA wishes to reserve judg-
ment on the proposed 1980 and 1990
expansions pending presentation by the
applicant of further information regarding
this issue.
Throughout this impact statement, the
growth inducing impact of the various
alternatives has been addressed. The
combination of the abilities to reimburse
additional potable water withdrawals from
the Colorado River through return flow
credits; to supply waste water for power
plant cooling, accommodating increased
electric power generation and; to increase
the capability of the community to treat
and dispose of waste water to comply with
Federal-State water quality standards, add
up to providing the Las Vegas Valley com-
munities with the tools necessary for con-
tinued residential, commercial, and indus-
trial growth in a relatively short period of
time.
In an air quality sense this kind of com-
munity growth in itself is not necessarily
adverse, but the rate, distribution, and
density of that growth may be. The
Environmental Protection Agency is cur-
rently providing contract assistance to
Nevada to prepare emission control strate^
gies to reduce the contributions from mo-
bile and stationary sources in the Clark
County Metropolitan area, and it would
be inopportune to initiate a program
which may pre-empt or overwhelm
effective implementation and mainte-
nance of those planning and enforcement
strategies. Therefore we acknowledge
this relationship and foresee further
air quality input.
The State of Nevada in conjunction with
EPA through provisions specified in
the Clean Air Act of 1970, require the
submittal of information sufficient
235
-------
to enable determination whether such
a facility will not violate "applicable
portions of the control strategy or
will not interfere with attainment or
maintenance of a national standard
either directly because of emissions
from it, or indirectly because of emis-
sions resulting from mobile source
activities associated with it." Since
the decision to proceed with Alternative
10 has been made, EPA does not want
to obviate the objective analysis of this
proposed power facility by the State.
Therefore our reservations with res-
pect to the power plant as the major
form of reclamation/reuse extend into
these regulatory and planning respon-
sibilities.
Above all, the abatement of pollution
from municipal and industrial sources
is the main objective of this proposed
project. Alternative 10 will more than
adequately facilitate this objective. The
recommended objective is designed to
collect and treat secondary effluent from
the existing Clark County waste-water
treatment plant, the existing Las Vegas
waste-water treatment plant, and the
existing City of Henderson waste-water
treatment plants. The treatment pro-
cesses employed are designed to produce
an effluent which will meet anticipated
effluent discharge limitations. The
primary objective of this alternative is
to treat waste water and discharge it to
Las Vegas Wash for maintenance of exis-
ting beneficial uses or make AWT effluent
available for beneficial reuse. As in all
alternatives, a portion of the effluent
would be available for in-valley irrigation
in the future. The increased quality of
flows provides for increased pollutant
reduction capability in the receiving
water, and the effluent characteristics
of Alternative 10 compared to the water
quality standards for Las Vegas Wash
and Lake Mead indicate that these stan-
dards would be more than met by dis-
charges from this process.
236
-------
-------
Board of County Commissioners, Clark County, Nevada,
Facilities Plan Annex A, Las Vegas Wash/Bay Pollution
Abatement Project, Las Vegas, Nevada, July 1974
Board of County Commissioners, Clark County, Nevada,
Addendum To The Environmental Assessment Annex B,
Las Vegas Wash/Bay Pollution Abatement Project, Las
Vegas, Nevada, July 1974
Board of County Commissioners, Clark County, Nevada,
Report to the Governor and the Legislative Commission,
Final Alternate Plan Las Vegas Wash/Bay Pollution
Abatement Project, Las Vegas, Nevada, July 1974
Las Vegas Valley Water District, Environmental Assessment
Pollution Abatement Project Las Vegas Wash and Bay,
Annex B, Las Vegas, Nevada, November 1972
Environmental Protection Agency, Conference in the Matter
of Pollution of the Interstate Waters of the Colorado
River and its Tributaries - Colorado, New Mexico,
Arizona, California, Nevada, Wyoming, Utah, Denver,
Colorado, April 26-27, 1972
Environmental Protection Agency, Summary Report - The
Mineral Quality Problem in the Colorado River Basin,
Denver and San Francisco, 1971
Environmental Protection Agency, Report on Pollution Affecting
Las Vegas Wash, Lake Mead and the Lower Colorado
River, Nevada-Arizona-California, Denver and San
Francisco, December 1971
Pacific Southwest Inter-Agency Committee, Upper Colorado
Region Comprehensive Framework Study, Appendix VII
Mineral Resources, June 1971
Pacific Southwest Inter-Agency Committee, Lower Colorado
Region Comprehensive Framework Study, Appendix II
The Region, June 1971
238
-------
Pacific Southwest Inter-Agency Committee, Lower Colorado
Region Comprehensive Framework Study, Appendix V
Water Resources, June 1971
Pacific Southwest Inter-Agency Committee, Lower Colorado
Region Comprehensive Framework Study, Appendix VI
Land Resources and Use, November 1970
Pacific Southwest Inter-Agency Committee, Lower Colorado
Region Comprehensive Framework Study, Appendix XIII
Fish and Wildlife, June 1971
Pacific Southwest Inter-Agency Committee, Lower Colorado
Region Comprehensive Framework Study, Appendix XIV
Electric Power, June 1971
Pacific Southwest Inter-Agency Committee, Lower Colorado
Region Comprehensive Framework Study, Appendix XV
Water Quality, Pollution Control, and Health Factors,
June 1971
Soil Conservation Service, U.S. Department of Agriculture,
General Soils for a Portion of Clark County, Nevada
(Advanced Data for Interim Use), Reno, Nevada,
August 12, 1974
Bureau of Reclamation, U.S. Department of the Interior,
Alternative Multiobjective Plans Emphasizing Water
Resource Use in Area V Colorado Planning Region,
Summary Report, Nevada State Study Team, April 1974
Martin, R.O.R. and Hanson, Ronald L., Reservoirs in the
United States, U.S. Geological Survey Water-Supply Paper
1838, Washington, D.C., 1966
Harbeck, G. Earl, Jr. and others, Water-Loss Investigations;
Lake Mead Studies, U.S. Geological Survey Professional
Paper 298, Washington, D.C. 1958
Office of Saline Water, Bureau of Reclamation, Colorado River
International Salinity Control Report - Special Report,
Boulder City, Nevada, September 1973
239
-------
Loeltz, Omar J. , Ground-Water Conditions in the Vicinity of
Lake Mead Base, Las Vegas Valley, Nevada, U.S.
Geological Survey Water-supply Paper 1669-0, Wash-
ington, D.C., 1963
Malmberg, Glenn T. , Available Water Supply of the Las Vegas
Ground-water Basin, Nevada, U.S. Geological Survey
Water Supply Paper 1780, Washington, D.C., 1965
Thomas, H. E. and others, Effects of Drought in the Colorado
River Basin, Bought in the Southwest, 1942-56, U.S.
Geological Survey Professional Paper 372-F, Washington,
D.C., 1963
Colorado River Board of California, Need for Controlling
Salinity of the Colorado River, Los Angeles, California,
August 1970
Duke, Raoul, Fear and Loathing in Las Vegas: A Savage
Journey to the Heart of the American Dream, Rolling
Stone, No. 95 and 96, November 1971
Bradley, W. G. and Niles, Wesley E., Study of the Impact on
the Ecology of Las Vegas Wash under Alternative Actions
in Water Quality Management, Final Report to the Las
Vegas Valley Water District, University of Nevada,
Las Vegas, December 1972
Henningson, Durham & Richardson, Inc. of Arizona, Sewer
Line Master Plan Update Report 1974, City of Las Vegas,
Nevada, August 5, 1974
Greater Las Vegas Chamber of Commerce, Las Vegas Report
1974, Las Vegas, 1974
240
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•o
•e
3
a
no. uo—n. n—i
WEDNESDAY, JULY 17, 1974
WASHINGTON, D.C.
Volume 39 • Number 138
PART III
ENVIRONMENTAL
PROTECTION
AGENCY
PREPARATION OF
ENVIRONMENTAL
IMPACT STATEMENTS
Notice of Proposed Rulemaking
-------
26254
ENVIRONMENTAL PROTECTION
AGENCY
[40 CFR Part «)
ItnSS.'S. ENVIRONMENTAL
IMPACT STATEMENTS
"one, M PropoMd Rulenuklng
PROPOSED RULES
lubpart fv-4ai
ral
Ewcuti»i8?!L.<*rapA)' Implemented by
arid th? °">er USM of March S, 1970,
Quality", frSi!",0'1 on Environmental
1»73 ii,,FSQ" °"«leUne« of August 1,
»~.-'_ r«iuires that ^n aBencle» ot the
detailed
•fcttoo , er """
ltjr of Chulantl1' aff«"ng the qual-
" environment. The ob-
Sec.
6.100 Purpcee and policy.
0.102 Definition*.
6,10* summary of prooeduTM lor Ixnpls-
menunc u» NEPA.
G.ioo Applicability.
0.108 Completion of N1CPA procedural b*-
for* eotr,n»ne»m»nt of admtalstra-
tlv« action.
«.110 General r«spon«iblluies.
Subpart II—Procedural
0.200 Ould«lln«a for determining when to
prepare an Impact «ta.t«maat.
0.202 Environmental aaaeesm^nt.
0.2O4 Environmental review.
fl.2O0 Notice or Intent.
0.208 Draft Impact •tatementi.
1.110 Rnal Impact suttmsuts
0.212 Kegatlve declarations and enilroa-
mental Impact appralsala.
0.314 Additional proctdune.
wbllc comment on the
the n«* '""1"'-
u —-oft£? "« ?«ix»ed rulemaklng
havel».?J;h«.»"bs«*ntlal changesThat
^."^•"""••Annal
l j> »*"*-
0.300 Cover nhMt.
6-303 Summary sheet.
0.304 Body of sUWment.
Suhp«rt D—Public
fl.400 General,
8.403 Public henDnga.
0.404 CumnvcnU on draft »na ft.ru.1 it»te-
ment*.
«.40ft Av-hlii.btl.ty of document*,
Bubpart C—OuMdtnM for C*mpJle«« WNh
MEM In the Title H Weetomiter Tr«*tm*nt
Werkt Cenvlructton Grant! Prepem
6,500 PurpOM.
0.909 Definition*.
6.504 Applicability.
0.5M Completion of OTfPA procedure* be-
fore commence ment of udminUtra-
tlv« tactlonj.
ft 508 Rflsponal bill tier
0.610 criteria for preparation of envlrtm-
mentaJ im[>*ct »t*tem*nt*.
0.512 ProcedurM for tropiementlrn the
. JiEPA.
8.BH Content and format of enTtrotxmenfcai
Impact ttateroenta.
•ubptrt F—OulrteflnM tor CompHane* WWh NfM
In Research •nd 0*v*lop*n*nt Program *n4
0.000 Purpoa*.
0,003 Definition*.
0.004 Applicabllltr.
R**pon»it>im.«*i.
0,008 Criteria for the prepftratlon of en-
vironmental Impact •ttttementa,
0 810 ProoedurM for eompllaAO* with OTA.
lit O—Ouldellnet fer
0700 PurpoM.
eioa Dcnnltlnni.
0.704 Applicability.
6.7M RMporuilbUltl«e.
0.708 Criteria for the preparation of en-
vironmental atijMiniiHiU and un-
paot itaunuut*.
0,710 Procedure! for compnano* with RKPA.
""SRS
....A In CanatructJen «f
ellltlec antf ractltty Wario
0.800 PurpOM.
eaoi DoflnlUons.
9.604 Applicability,
"9M BwponslblUUM.
««»« Criteria tor tte prsparatUB of en-
TlronmsnUl asassnunu sail inv
paot auwment*
e «IO Praeaduns for oompllanoa via HIP*.
1. Flowch*rt.
3. (pagtt 1.) Notice of Intent TraiumlttAl
Uemcnndum—fiugge«ted Format.
(pac* 9.) KoUoe of Intent—Suggested For-
mAt.
>. H*w> tuleaw—SuirgeiUd Format.
4. NegaUv* Oaolaratlort—auggMted Format.
6. Environmental Impact Appralaal—Buff-
geated Format.
0. Cover Bbeet Format for BnvIronmentAl
Impact Statements.
7. Summary Sheet Format for Environmental
Impact Statement*.
0. Flowchart for ORD.
0 Flowchart lor OSWUP.
AorHOirrT: Seo. 102, 103, >3 Stat BS4.
fobptrt A—Oenenl
| 6.10O Purpose and policy.
(ft) The National Environmental
Pollcv Act of 196S, Implemented by
Executive Order 11514 and the Council
oo Environmental Quality's Guidelines
of Au(U»t 1, 1813 (38 FR 20550), requires
thftt aU agenclen of the Federal Govern-
ment prepare detailed environmental
•Utementi on proposals for legislation
and other major Federal action Hgntn-
cantly affecting the quality of the human
environment. The objective of the Act Is
to build Into the agency declalon-maklne
proceM an appropriate and careful con-
sideration o-f all environmental upects
of proposed actions.
(b) This part establishes Environmen-
tal Protection Afency policy and proce-
dure) for the Identification and analysis
of the environmental Impact of Agency
actions, and the preparation and proc-
euing ol environmental Impact state-
ments when significant Impacts on the
environment are anticipated.
16.102 Definition*.
(a) "Environmental assessment" la a
•written analysis submitted to the Agency
by Its grantees or contractors describing
the environmental Impacts of proposed
actions undertaken with the financial
support of tbe Agency. For plans, the
assessment must be an Integral part of
the plan submitted to the Agency for re-
view. In other cases, the assessment will
be a separata document.
(b) "Environmental review" Is a for-
mal evaluation undertaken by the
Agency to determine whether a proponed
Agency action may have n significant
Impact on the environment. The assess-
ment l> one of the major sourcee of In-
formation used In this review.
(c) "Notice of Intent" Is a memoran-
dum announcing to Federal, State, and
local agendas, and to Interested persons,
that ft draft environmental Impact state-
ment will be prepared and processed.
(d) "Environmental Impact state-
ment** Is a report, prepared by the
Agency, which Identifies and analyzes In
detail the environmental impacts ot a
proposed Agency action.
(*) "Negative declaration" Is a written
announcement, prepared subsequent to
the en-rtronmenUU review, which states
that tbe Aftney has decided not to pre-
pare an environment*! Impact state-
ment.
(f) "Environmental Impact appraisal"
Is an abbreviated document, based on an
environmental review, which supports a
negative declaration. It describes a pro-
posed Amncy action, Ite expected envi-
ronmental Impact, and the bails for the
conclusion that no significant Impact Is
anticipated.
(g> "Responsible official" will usually
be either a Regional Administrator or a
Deputy Assistant Administrator. He is
responsible, tor assuring that environ-
mental Impact statements and other as-
sociated documents are prepared, Re-
sponsible officials are Identified for the
various Agency program offlcee In the
subport* following Bubpart D.
(h) "Interested persons" are Individ-
uals, groups, organizations, corporations,
or other nongovernmental unlU, Includ-
ing an applicant for an Agency contract
or grant and conservation groups, who
may be Interested In. affected by, or tech-
nically competent to comment on the
environmental Impact of the proposed
Agency action.
§ 6.104 Summary of procedures for
Implementing the NKI'A.
(a) Environmental ossesament. Envi-
ronmental iwumentt must' be sub-
mitted to the Agency by IU grantees and
contractors, as specified In the subparts
following Subpart D of this part. The
assessment is used by the Agency in de-
ciding If an Impact statement Is required
and in preparing a statement If it de-
cides to prepare one.
Co) Environmental review. Environ-
mental reviews shall be made of pro-
posed and certain ongoing action) (as
required In I 6 108 Development of favorable reports
on legislation (see paragraph (d) ol this
section) initiated elsewhere and not ac-
companied by an Impact statement, pro-
vided It relates to or affects matters with-
in EPA'0 primary areas of responsibility;
(3) For the construction grants pro-
gram under Title n of the FWPCA
Amendments of. 1972, those administra-
tive action) specified In I 6.504;
(4) For the Office of Research and
Development, those administrative
actions specified In ! 6.604;
(5) For other programs, the award of
a grant or contract (see Subparts O and
H) except for those cases listed In para-
graph (b) of this section;
<«) For other programs, actual phy-
sical commencement of a project or ac-
tivity undertaken with inhouse funds
(Intramural project). See Subparts a
andH.
(b) Ths requirements of this part do
not apply to environmentally protective
regulatory activities undertaken by the
Agency.
(c) Application to ongoing actions.
ThU regulation shall apply to uncom-
pleted and continuing ARency actions
Initiated prior to the promulgation of
these procedures when substantial funds
have not been released and modifications
of or alternatives to the Agency action
are still available. An environmental Im-
pact statement aliall be prepared for each.
project found to have significant envi-
ronmental consequences, as determined
In accordance with S ft.200.
(d) Application to legislative propos-
als. (1) As noted in paragraphs (a) (1)
and (21 of this section, environmental
Impact statements shall be prepared for
Ictftt'a'.ivo ijrojwsttls or favorable reports
relating to legislation. Because of the
nature ol the legislative proceaa, impact
statements for legislation must be pre-
pared and reviewed In accordance with
the procedures followed In the develop-
ment and review of the legislative matter.
These procedures are described in Office
of Management and Budget Circular No.
A-U.
26255
(2) A working draft Impact statement
shall be prepared by the Agency office
responsible for preparing Uie legislative
proposal or report on legislation. It shall
be prepared concurrently with the de-
velopment of the legislative proposal or
report and shall contain, where appro-
priate, tbe, information required In
{ 9.304. The statement shall be circulated
for Internal Agency review with the legis-
lative proposal or report and other sup-
porting documentation. The working
draft statement shall be modified In ac-
cordance with changes made in the pro-
posal or report during the internal re-
view, All major alternatives developed
during the formulation and review of the
propoaal or report should be retained In
the working draft statement.
(1) The working draft Impact state-
ment shall accompany the legislative
proposal or report to OMB. The Agency
shall revise the working draft statement,
as necessary, to respond to comments
made by OMB and Federal agencies.
(11) Upon transmlttal ot the legislative
proposal or report to Congress, the work-
Ing draft impact statement will be for-
warded to CT£Q and the Congress as a
formal legislative Impact statement.
Coplea will be distributed in accordance
with 9 6.208(b) (2) <»,(«), (Iv) (d). and
(Iv) (e>. At the same time copies are sent
to the Council on Environmental Quality,
two (2) copies shall be sent to the Office
of Federal Activities and the originating
office.
(Ill) Comments received on the legis-
lative Impact statement by the Agency
shall be forwarded to the appropriate
Congressional Committees, if appropri-
ate, the Agency may wish to respond to
specific comments and forward those
with the comments. Because legislation
undergoes continuous changes In Con-
gress, no final Impact statement need be
prepared by the Agency.
§6.108 Complrllon of NEPA prott.
diires before cnminrncrmcnl of ad.
mlnulnillve action.
(a) When an Impact statement will be
prepared. Except when requested by the
responsible official In writing and ap-
.proved by the Council on Environmental
Quality, no administrative action shall
be taken sooner than ninety (90) cal-
endar days after a draft statement has
been distributed or sooner than thirty
(30) calendar days otter the final state-
ment has been circulated and made pub-
lic, the thirty (30) day period and ninety
(90) day period may run concurrently
to the extent that they overlap. In addi-
tion, the proposed uctlon should be modi-
fled to conform with any changes the
Agency deems necessary,
(b) When an impact statement will
not be prepared. It the Agency decides
not to prepare a statement on any action
0:1 which a negative declaration with en-
vironmental appraisal Is required (as
specified In the subpari* foilov. ing Sub-
part D), no administrative action shall
be taken sooner than fifteen (15) flays
after Issuance of the negative declara-
tion.
HOMAl MOUTH, VOL J«, NO. I >*—WWNKDAT, JUW 17, 1*74
KOMAt MOUTH, VOL 19, NO. US—WIONfSDAV, JUIY 17, 1(74
-------
26256
§6.110 General responsibilities.
(ft) Responsible official. When required, assures that draft
statements are prepared and distributed
at the earliest practicable point in the
Agency's project formulation process,
their Internal and external review ts co-
ordinated, and final statements are pre-
pared and distributed.
(3) When an impact statement is not
prepared, assures that negative declara-
tions and environmental appraisals are
prepared and distributed for those ac-
tions requiring them.
(4) Consults with the Office of Fed-
eral Activities on actions involving unre-
solved conflicts with other Federal
agencies,
(b) Office of Federal Activities. (1)
Provides Agency wide policy guidance
and assures that Agency components es-
tablish and maintain adequate adminis-
trative procedures to comply with this
part.
(2) Monitors the overall timeliness
and quality of the Agency effort to
comply with this part.
(3) Provides assistance to responsible
officials as required.
(4) Coordinates the training of per-
sonnel Involved in the review and prep-
aration of environmental impact state-
ments and other associated documents.
(B) Acts as Agency liaison with the
Council on Environmental Quality and
other Federal and State entitles on
matters of Agency policy and adminis-
trative mechanisms to facilitate external
review of Agency environmental impact
statements, to determine lead Agency,
and to improve the uniformity of the
NEPA procedures of Federal agencies.
(6) Advises the Administrator and
Deputy Administrator on projects which
involve more than one Agency compo-
nent, are highly controversial, are na-
Uonaily nlguificant, or "pioneer" Agency
policy, when these projects have had or
should have an environmental impact
statement prepared on them.
(c) Office o1 Public Affatra. U) Assists
the Office of Federal Activities and re-
sponsible officials by answering the pub-
lic's queries on the Impact statement
process and on specific impact state-
ments, and by directing requests for
copies ot specific documents to the ap-
propriate regional office or pvogram,
(2> Analyzes the present procedures
for public participation, and develops
and recommends to the Office of Federal
Activities a program to Improve those
-procedures and increase public partici-
pation.
id' Regional Office Division of Public
Affairs. (1) Assists the responsible offi-
cial or his designee on matters pertain-
ing to negative declarations, notices of
intent, press releases, and other public
notification procedures. .
PROPOSED RULES
(2) Assists the responsible official or
his deslgnee by answering the public's
queries on the impact statement process
and on specific Impact statements, and
by filling requests for copies of specific
documents.
(e) Office of the Assistant Adminis*
trators and Regional Attirtinistrators.
Provides specific policy guidance to their
respective offices and assures that those
offices establish and maintain adequate
administrative procedures to comply
with this part.
(2) Monitor the overall timeliness and
quality of their respective component's
efforts to comply with this part.
(3) Act as liaison between their com-
ponents and the Office of Federal Activ-
ities and between their components and
other Assistant Administrators or Re-
gional Administrators on matters of
agencywide policy and procedures.
(4) Advise the Administrator and
Deputy Administrator through the Office
of Federal Activities, on projects or ac-
tivities within their respective areas of
responsibilities which involve more than
one Agency component, are highly con-
troversial, are nationally significant or
"pioneer" Agency policy, when these
projects have had or should have an en-
vironmental Impact statement prepared
on them.
shall be subjected to an environmental
review. This review shall be a continuing
one and should commence at the ear-
liest possible point in the development of
the project. It shall consist of a study of
the proposed program or project, includ-
ing a review of any environmental as-
sessments received, to identify and
evaluate the expected and potential en-
vironmental impacts of the action and
alternatives to it It win determine
whether a significant Impact is antici-
pated from the proposed action, whether
any changes can be made In the project
to eliminate m mitigate these impacts,
and whether an environmental Impact
statement is required.
(b) The responsible official shall de-
termine the pfoper scope ot the environ-
mental review. If a plan cu»eilm pro-
posed actions Is available. It should b»
reviewed before making Oils determina-
tion (see I 8.208(a) (3».
5 6.206 Node* of intent.
General. (1) when an environ-
mental review Indicates a significant Im-
pact may oecur and that Impact cannot
be eliminated by making appropriate
changes tn tte project, a notice of Intent.
announcing the preparation of a draft
Impact statement, shall be Issued by the
responsible official The notice «ball
briefly describe the Agency action. Its
location ami the Issues involved (see
Exhibit a).
(2) The purpose of a notice ot intent is
to involve other Government agencies
and Interested persona as early ai possi-
ble In the planning and evaluation of
Agency actions which embody significant
environmental Impacts. This device
should facilitate coordination during the
preparation of a draft Impact statement
and aware that environmental values
will be Identified and weighed from the
outset, rather that accommodated by ad-
justments at the end ot the dedMou-
maklng process.
(3) M the project Involves a grant ap-
plicant or potential contractor, he must
submit any data which the Agency re-
miests tor preparation of the statement.
(b) Specific actimi. The specific ac-
tions that should be taken with respect
to notices of intent are as follows:
n> When the review process Indicates
there will be a significant Impact, prepare
a notice of Intent immediately after OM
renew.
(2) Forward copies of the notice of In-
tent to:
(1) The appropriate State and local
agencies and to the appropriate State.
regional, and metropolitan clearing-
houses.
(ii> Potentially interested persons.
till) The office of federal Activities
and Hie Office of Public Affairs.
The Office ot Legislation so they
will be able to answer any queries from
Congress on the matter.
(31 Submit to a local newspaper,
which has adequate circulation to cover
the area that will be affected by the
project, » brief newa release (MM Ex-
hibit 3) Informing the public that an Im-
pact statement will be prepared on a par-
ticular project. News releases mar be
submitted to other media ai appropriate.
(c) Scatonot o/Jtcs oittttonce to pro-
gram oSHctt, Regional offices will provide
aMstanee to program offices In taking
these specific actions when the state-
ment originates In a program office.
g 6.3M Draft i«i
(a) General. (1) The responsible offi-
cial shau assure that a draft environ-
mental Impact statement is prepared as
«oon as practicable after the release of
the notice ot intent. Prior to release to
the Council on Environmental Quality
(CEQ), a preliminary version of the
draft statement may be circulated for
review to other offices within the Agency
with collateral Interest In or technical
expertise related to the action. There-
after, the dralt statement shall be sent
to CEQ and circulated to Federal, state,
and local agencies with special expertise
or jurisdiction by lav, and to Interested
persons. If the responsible official deter-
mines that a public hearing on the proj-
ect Is warranted, the hearing will be held
after preparation of the draft statement
and In accordance with the requirements
of t 6.402.
(2) Draft Impact statements should
be prepared at the earliest practicable
point In the project development. Where
a plan or program baa been developed by
the Agency or submitted to the Agency
for approval, the relationship between
the plan and the subsequent projects en-
compassed by It shall be evaluated to
determine the preferable and most mean-
ingful point In time for preparing an im-
pact statement. Where practicable, an
environmental Impact statement will be
drafted for the total program at the
overall planning stage. Subsequently,
component projects Included to the plan
will not require Individual statements un-
less they deviate substantially from prior
plans, or unless t&« plans do not provide
sufficient detail to fully assess significant
Impacts of individual projects. Plans
shall be reevaluated by the responsible
official to monitor the cumulative Impact
of the component projects and to pre-
clude the plans' obsolescence.
(b) Specific aetlora. The specific ac-
tions that should be taken wtth respect
to draft Impact statements are as follows:
(1) Before transmitting the draft
statement to the Council on Environ'
mental Quality, the responsible official
shall:
(1) Notify by phone the Office of Fed-
eral Activities and the headquarters
Impact atatemeni coordinator for the
program office originating the statement
that a draft Impact statement has been
prepared. When the originating office Is
a regional office and the project Is re-
lated to water quality management, the
Regional Administrator will notify by
phone the office of Federal Activities and
the Oil and Special Materials Control
Division, Office of Water Program Op-
eraUoia, that the draft Impact statement
has been prepared.
(11) Send two (a) copies of the draft
statement to each of the appropriate
offices in paragraph (b)(l)Ct) ot this
section.
(» It neither of the above offices
requests any changes within a ten (10)
working day period after notification the
responsible official shall:
Uc ASJJJ
c« tbe transmlttal to tbe Coisaca « *r,
vtronmentsJ Quality and the- plans "•
local pncv release. *|
(ill) Notify the Office of LegisUtU0 !;
the transmrttal so they vul b* «*• LJJ
answer any Queries from Congress CD "~
matter. ._
Provide copies of Jhe draft """^
aent to: afl
(«> The Office of Legislation X ""
reouast copies. _—
The once of Public ASau* "^
vide two (2) copies. _jrf-
(c) The appropriate offices of f^j.)
Ing Federal aganclai Unit bare 0*g£
expertise or Jurisdiction by la* "ijj
respect to any Impacts Involve* *
Council on Environmental
Guidelines (40 ere ISOO.i and
dlxes n-rn thereof) specify <
eles to which draft stateme
sent for official review and comm««*^
<3> copies of the impart
should be provided each ag
they have made a specific
more copies. The agencies are
to reply directly to the orlglnet™ "J^
office. Commenting agencies ebau *T«»
at least forty-five (45) calendar «~;
to reply (the reply period aialJ«"Ji
mence /ram the date of f^^yZnf
the FHWUL Rnisra ot uste <* EJJ.
ments received by the Council «• *
Tonmental Quality) : thereafter,
be presumed that, nnJttS * "
tension has been requested, l^
has no comment to make. ZPA B^Ttif}
extensions where practical ol flfis*w
or more calendar days. , ^f
(d) The appropriate State "fJS
agencies and to the appropriate °Ss
and metropolitan cleiulnf
time limits for review and
shan be the same as those
Federal agencies. .M*
(e) Interested persons. T6* -ail
limits for review and extension* *5st»1
the same as those available to ""^
agencies. ^-«*tt0
(v) Submit to the loeml n***«ir
and other appropriate media • I*~\at
lease (see Exhibit 3 of this p»rt> *Jn5
draft statement Is available for ^
and where copies mar
(vl) Send two (J> copies
mary sheet (see I 6.30J> to
of Management and Budget.
Uon and Management Briton*
(0 Ktflonal office eautunc*
gram office. If requested,
will provide assistance to
(n taking these specific acttcos ""fW
Impact statement originates IB * *"
gram office.
I 6.2 18 Final ln.it.ct •1"*"*°'''_d |l
(a) Final t«at*ments shaa
all substantive comments ras*a "JSi
the review of the draft Impact »*SI
Special care should be takes
fully to comments that are **
with the Agency's position "*•
(b> Distribution and
action. «U1 be as MX***, *ftt»>*
statements m I e.aog (b) and W 4
cue of Federal and State
RDEUL HOISTEK, VOL. 19, NO. 131—VVIDN1SOAY, JIHV 17, 1974
HDUA1 INIITH, VOL 39, NO, MS-WIONUOAY, 1U11 17, 1*74
-------
"•>» or
• draft state-
*.copsr °' ""> nnal "tafc
.
JWUctot .?.!*1)* » MPy. n ««"* to «n
«>e numb,1? *»» oe «nt a copy. Where
"Memeot 1. L c°mm«"«« on the draft
.£. uch that distribution of
" to all commenting
' °-
offlM Preparing the
con8utt wlth *» OFA.
il on
* statement that per-
'"i the decision may
t consideration by
-••wuiQ got ^. —*» cases the Agency
^ "» Wolea El "Jntotatrattve action
dam «•«..* **°l for at IMU* flft^^u. /i«*
• n «te . ca-
*'Bain,* ••>(, . v*«WsB6a tn ai days to comment as measured from
the date of the written request. In all
cases where consultation has occurred,
the agencies consulted should receive
copies of either the notice of Intent and
impact statement or negative declara-
tion and appraisal prepared on the
action.
(3) If aa impact statement Is to be
prepared on a project and wetland* may
be affected, the required consultation
may be deterred until the preparation of
the draft statement.
(c) rish and wildli/t, The Agency Is
subject to the requirements of the Fish
and Wildlife Coordination Act, It V.B.C.
001 et seq. The following procedures shall
be applied to all administrative actions
covered by this part:
(1) Whenever an Agency action will
result In the control or modification of
any stream or other body of water, for
any purpose whatever. Including navi-
gation and drainage, the Agency shall
consult with the United States Fish and
WUdllto Service, Department of the In-
terior, and the head of the agency exer-
cising administration over tho wildlife
resources of the particular State In which
the action will take place with a view to
the conservation of wildlife resources.
Such consultation shall take place during
the environmental review of an action.
Requests for consultation and the re-
sults of such consultation shall be doc-
umented In writing. The agencies should
be given thirty (30) days to comment as
measured from the date of 'the written
request. The Agency should employ the
results of such consultation la deter-
mining If an Impact statement Is needed.
In all cases where consultation has oc-
curred, the agencies consulted should re-
ceive copies of either the notice of Intent
and Impact statement or negative dec-
laration and appraisal prepared on the
action.
(2) If an Impact statement is to be
prepared on a project which may result
in the contxol or modification of a stream
or body of water, the required consulta-
tion may be deferred until the prepara-
tion of the draft statement.
Subpsrt C—Content of Environmental
Impact Statement!
| 6.100 Com sheM.
The cover sheet shall Indicate the type
of statement (draft or final), the official
project name, the responsible Agency
office, the date, and the signature of the
responsible official. The format Is shown
In Exhibit 8.
I 6.SOZ Summary »h«rt.
The summary sheet shall conform to
the format prescribed In Appendix I of
the August 1, lt?9. Council on Environ-
mental Quality's Guidelines. The format
is shown in Exhibit 7.
I6.S04 BadrofsUlemem.
The body of the Impact statement shall
Identify, develop, and analyze the perti-
nent issues Included in the seven sections
below. Each section need not be a sep-
arate chapter In the statement. Impact
statements shall not be justification doc-
uments tor proposed Agency tundlng or
actions. Rather, they shall be objective
evaluations of actions and their alterna-
tives In light of all environmental con-
siderations. Environmental Impact state-
ment! shall be prepared using a
systematic, Interdisciplinary approach.
Statements shall Incorporate all relevant
analytical disciplines and shall provide
meaningful and factual data. Informa-
tion, and analyses. The presentation
should be simple and concise, yet Include
aU facts necessary to permit Independent
MDIIAL liaiSTM, VOL J«, NO. Ill—WIDNIIOAV, JUtV 17. 1*74
PROPOSED RULES
26259
evaluation and appraisal of the benefl-
clal and adverse environmental effects of
alternative actions. The amount of de-
tail provided should be commensurate
with the extent and expected Impact of
the actions, and the amount of Informa-
tion required at the particular level of
decision making. To the extent possible,
statements shall not be drafted In a style
which requires extensive scientific or
technical expertise to comprehend and
evaluate the environmental Impact of an
Agency action.
(a* Background and description of
the proposed action. Describe the recom-
mended or proposed action, UK purpose.
where it Is located and its time setting.
To prevent piecemeal decision making,
the project shall be described In as broad
a context as necessary. The relationship
to other projects and proposals directly
affected by or stemming from the pro-
posed project shall be discussed, Includ-
ing not only other Agency activities, but
also those of other Governmental and
private organizations. Development and
population trends In the project area and
the assumptions on which they are based
shall also be Included. Maps, photos, and
artist sketches should be Incorporated If
available when they help deplcl the envi-
ronmental setting. If not enclosed, sup-
porting documents should be referenced.
(b) Alternative* to the proposed ac-
tion. Develop, describe, and objectively
weigh alternatives to any proposed ac-
tion. The analysis should be sufficiently
detailed to reveal the Agency's compara-
tive evaluation of the environmental ef-
fects, costs, and risks of the proposed
action and each reasonable alternative.
The analysis of alternatives should In-
clude the alternative of taking no action
or of postponing action, as well as al-
ternatives having different environ-
mental Impacts. On projects Involving
construction, alternative sites must be
considered. This analysis shall evaluate
alternatives In such a manner that re-
viewers Independently can judge their
relative desirability. If a cost-benefit
analysis Is prepared. It should be ap-
pended to the statement. In addition, the
reasons why the proposed action Is be-
lieved by the Agency to be the best course
of action shall be explained.
(c) environmental Impact ol the fro-
voted action. (1) Describe the primary
and secondary environmental Impacts.
both beneficial and adverse, anticipated
from the action. The scope of the de-
acrlptlon shall Include both short- and
long-term Impacts. Attention should be
given to discussing those factors most
directly Impacted by the proposed action.
(3) Primary Impact* are those that
can be attributed directly to the action
or project. For example, If the action Is a
field experiment, materials Introduced
into the environment may damage cer-
tain flora or fauna. If the action Involves
construction of a facility, construction
activities may damage certain aspects of
the environment. In addition, operation
ol the facility may have continuing en-
vironmental effects, both beneficial and
adverse.
(3) Secondary impacts are indirect or
Induced Impacts. If the action Involves
construction of a facility, such as a
wastewater treatment system or art of-
fice building or laboratory, it may stim-
ulate or induce secondary effects In the
form of associated Investments and
changed patterns of social and economic
activities. Particular attention should be
paid to changes In population patterns or
growth. When such changes are signifi-
cant, their effect on the resource base,
including land use, water quality and
quantity, air quality, and public services,
should be determined. A discussion of
how these impacts conform or conflict
with the objectives and specific terms of
approved or proposed Federal, State, and
local land use plans, policies, and con-
trols for the area should be Included. If a
conflict exists, the Agency should give the
reasons why It has decided to proceed
notwithstanding the absence of full
reconciliation.
(41 The following sections discuss In
more detail some ol the Items that shall
be considered In describing the impact of
the proposed action.
(d) Adverse impacts which cannot be
avoided should the proposal be imple-
mented. Describe the kinds and magni-
tudes of adverse Impacts which cannot
be reduced In severity or which can be
reduced to an acceptable level but not
eliminated. These may Include water or
air pollution, undesirable land use pat-
terns, damage to ecological systems,
urban congestion, threats to health or
other consequences adverse to the en-
vironmental goals set out In section
101 (bi of the National Environmental
Policy Act Remedial, protective, and
mltigatlve measures which will be taken
as part of the proposed action shall be
identified. These measures to prevent,
eliminate, reduce, or compensate for any
environmentally detrimental aspect of
the proposed action shall Include those of
the Agency and others; e.g., its contrac-
tors and grantees.
(e) Relationship between local snort
term uses ol man's environment and the
maintenance and enhancement ot lone
term productivity. Describe the extent to
which the proposed action Involves
tradeoffs between short term environ-
mental gains at the expense of long term
losses or vice-versa and the extent to
which the proposed action forecloses
future options. Special attention shall
be given to effects which narrow the
range of beneficial uses of the environ-
ment or pose long term risks to health or
safety. Those who may reap windfall
gains or suffer significant decrease :n
current property value from the pre-
pared project shall be Identified. In ad-
dition, the reason the proposed action Is
believed by the Agency to be Justified
now, rather than reserving a long term
option for other alternatives, Including
no use, shall be explained.
(f) /rreuerilole and Irretrievable
comments ol resources which would be
Involved in the proposed action should it
6« Implemented. Describe the extent to
which the proposed action curtails the
diversity and range of beneficial uses of
the environment. For example, a deci-
sion to dispose of the treated effluent
from a wastewater treatment system
rather than reclaim it will result in the
irretrievable loss of that water. Including
nutrient constituents, Secondary Im-
pacts, such as Induced growth in unde-
veloped areas, may make alternative
uses of that land impossible. Also, Ir-
reversible damage can result from en-
vironmental accidents associated with
the action. Any irretrievable and signifi-
cant commitments of resources shall be
evaluated to assure that such current
consumption Is justified.
(g) A discussion o] problems and ob-
jections raised by other Federal, State,
and local agencies and by interested per-
sons in this review process. Final state-
ments (and dralt statements If ap-
propriate) shall summarize the com-
ments and suggestions made by review-
ing organizations and shall describe the
disposition of Issues surfaced (e.g., revi-
sions to the proposed action to mitigate
anticipated Impacts or objections). In
particular, they shall address the major
Issues raised when the Agency position
Is at variance with recommendations
and objections (e.g.. reasons why specific
comments and suggestions could not be
adopted, and factors of overriding im-
portance prohibiting the incorporation
of suggestions). Reviewer's statements
should be set forth In a "comment" and
discussed In a "response," In addition,
the source of all comment* should be
clearly Identified and copies of the com-
ments (or summaries where a response
has been exceptionally voluminous)
should be attached to the final state-
ment.
Subpart 0—Public Participation
8 6.400 General.
Public participation Is an Integral part
of the Agency planning process. It con-
sists of continuous, two-way communica-
tion keeping the public fully Informed
about the status and progress of studies
and findings, and actively soliciting com-
ments from all concerned and affected
groups and Individuals.
$ ft. 102 Public hearing!.
(a) Public hearings on draft Impact
statements shall be held when the re-
sponsible official determines that a pub-
lic hearing would facilitate the resolu-
tion of conflict or significant public
controversy.
(b) When public hearings are to be
held, the Agency must notify the public
of the hearing In the draft statement or
Immediately after distribution ot the
draft statement. If a notice is Included In
the statement, It must follow the sum-
mary sheet at the beginning of the state-
ment. This public notification must In-
clude at least fifteen (16) days prior to
the date of such hearing:
(1) Notification to the public by ade-
quate advertisement identifying the proj -
ret, announcing the date, time, and place
of such hearing, and announcing the
availability of detailed Information on
HBI«M MOI»», VOl. 3», NO. 131—WIDNKPAV, lull 17, l»74
-------
26260
the proposed project for public Inspec-
tlon at one or more locations In the area
in which the project will be located. "De-
tailed Information" shall Include a copy
of the project application and the draft
environmental Impact statement.
(2) Notification to the appropriate
State and local agencies and to the ap-
propriate State and metropolitan clear-
inghouses.
(3) Notification to Interested persons.
(c) A written record of the hearing
shall be made. As a minimum the record
shall contain a list of witnesses together
with the text of each presentation. Gen-
erally, a stenographer should be used. A
summary of the record, including the Is-
sues raised, conflicts resolved and unre-
solved, and any other significant portions
of the record, shall be appended to the
final Impact statement.
(d) When a public hearing has been
held by another Federal, State, or local
agency on an Agency action, additional
bearings need not necessarily ensure. The
responsible official shall decide if addi-
tional hearings are required.
(e) When a program office Is the
originating office, the appropriate re-
gional office will provide assistance to
the originating office in holding any pub-
lic hearing U assistance Is requested.
86.404 Comments on the drift Mid
fins) slalemenls.
(a) Draft impact statements and neg-
ative declarations shall be made avail-
able to the public to assure the fullest
practical provision of timely public In-
formation and understanding of Federal
plant and programs. In addition, public
hearings, notices of intent, and press re-
leases will be employed by the Agency to
ensure adequate public Involvement.
Final environmental Impact state-
ments shall be furnished to all interested
persons who submitted written com-
ments on the draft Impact statement.
This la to enable public organizations to
comment on the final statement to the
Agency or the Council on Envlron-
. mental Quality, if they so desire, within
the thirty (30) calendar day period prior
to Agency administrative action on the
proposal.
§ 6.406 Availability of document!.
(a) Draft and final environmental Im-
pact statements, negative declarations,
and environmental impact appraisals
shall be made available for public review
at the following locations:
(1 > The originating office.
<2> The Office of Public Affairs for
draft and final Impact statements only.
(b) The Agency will endeavor to print
sufficient copies of draft and final en-
vironmental Impact statements to meet
anticipated demand. A nominal fee may
be charged for copies requested by the
public.
(c) Lists of impact statements pre-
pared or under preparation and lists of
negative declarations prepared will be
available at both the regional and head-
quarters Offices of Public Affairs.
PROPOSED RULES
Subpsrt E—Guidelines lor Compliance
With NEPA In the TKto n Wastmnter
Trestmint Work* Construction Qrantf
Program
{6.500 Purport.
This subpart amplifies the general EPA
polices and procedures described in Sub-
part A through D by providing detailed
procedures for compliance with NEPA in
the wastewater treatment works con-
struction grant program.
8 6.502 Definitions.
(a) "Responsible official." The respon-
sible official for Agency actions covered
by this subpart is the Regional Admin-
istrator.
(b) "NEPA-associated documents."
Notices of latent, negative declarations,
environmental appraisals, news releases,
Impact statements, and assessments.
Approval of all faculties plans ex-
cept as provided In paragraph (a) (5) of
this section:
(3) Award of a step 2, S, 3 and 3, and
2/3 grant, if an approved facilities plan
was not required (during the transition
from the present planning requirements
to the new ones [see { 6.512(f) ]); how-
ever, when a step 2 grant Is to be
awarded, the NEPA procedures must be
completed prior to the award of the step
2 grant except as provided in paragraph
(a) (B) of this section, and once the
NEPA procedures have been completed
at step 2 they need not be applied again
at step 3 except as specified In paragraph
(a) (4) of this section;
(«> Award of a step 2. 3, 2 and 3, and
2/3 grant when either the project or Its
Impact has changed significantly from
that specified In the approved facilities
plan, except as provided in paragraph
(a) (6) of this section;
(5) A facilities plan may be approved
and a step 2 grant awarded prior to com-
pletion of an Impact statement when the
Regional Administrator determines that
excessive costs would be Incurred If
award of a step 2 grant were delayed
pending completion of the Impact state-
ment, provided the Regional Administra-
tor also determines that there Is no sub-
stantial risk that preparation of plans
and specifications under step 2 will fore-
close options that must be considered In
the Impact statement. The Regional Ad-
ministrator shall document each such
decision in writing.
(b) Administrative actions excluded.
The Agency actions Halted below are not
subject to the requirements of this part.
(1) Approval of State priority lists;
(2) Award of a step I grant;
(3) Award of a section 208 planning
grant;
(4) Approval of engineering plans and
specifications;
<5> Issuance of an invitation for bid;
(6) Actual physical commencement of
building or fabrication;
(7) Award of a section 208 grant for
reimbursement;
(8) Award of grant Increases jwo-
vMed, however, That | 8.504(a) (4) does
not apply;
<9) Program grant awards to State
and interstate agencies:
(10) Training grants and contracts.
(c) Retroactive application. (1) This
subpart shall be applied to ongoing
wastewater treatment works for which
grant awards were made prior to the
promulgation of these guidelines when
substantial funds have not been released
and modifications or alternatives to the
project are still available. The Regional
Administrator Shan ensure that an envi-
ronmental Impact statement shall be
prepared for each such works found to
have a significant Impact In accordance
with i 6.510. The grantee must be
promptly notified in writing of the deci-
sion to prepare an Impact statement.
(2) On such works, either oul or a por-
tion of the project work may be stopped
by the Regional Administrator pending
completion of the statement, If he deter-
mines that a work stoppage is warranted.
to reduce the risk of Incurring substan-
tial additional costs for work which the
impact statement may Indicate will have
to be abandoned or substantially
changed. The Regional Administrator
may request a written statement from
the grantee to assist him in making this
decision. The statement should Include:
A list of what work should and should
not continue: a discussion of potential
changes the Impact statement might rec-
ommend In the work discussed in the
above list; and the reasons why the work
in question should or should not con-
tinue. Upon a determination of partial
or complete work stoppage by the Re-
gional Administrator, the appropriate
grant action would be the Issuance of
a stop-work order to suspend work or a
bilateral agreement to suspend project
work, effected through a grant amend-
ment, or in some cases, the issuance of
a termination notice.
|6.506 Completion of NEPA proce-
dures before commencement of ad-
ministrative actions.
No administrative action can be taken
until an impact statement or negative
declaration with appraisal has been pre-
pared In accordance with I 6.108.
i 6.508 ReapomlfclliliM.
(a) Resfansfole official. The responsi-
ble official for Agency actions covered by
this subp&rt Is the Regional Adminis-
trator. The responsibilities of the Region-
al Administrator in addition to those In
j6.UO areto:
(1) Assist the Office of Federal Activi-
ties in coordinating the training of per-
sonnel Involved In the review and prepa-
ration of HEPA-assoclated documents.
(2) Require of grant applicants and
those who have submitted plans for ap-
proval, the Information the regional
office requires to comply with these
guidelines.
(3) Consult with the Office of Federal
Activities concerning works or plans
which significantly affect more than one
regional office, are highly controversial,
are of national significant or "pioneer"
Agency policy when these works have
had or should have had an environmental
Impact statement prepared on them.
(b) Assistant Administrator. Ifce re-
sponsibilities of the Office of the Assistant
Administrator, as described In I e.llO(e),
shall be assumed by the Assistant Admin-
istrator for Water and Hazardous Mate-
rials for Agency actions covered by this
subpart.
(c)OU and ffazardoiu Materials Divi-
sion, Office at Water Program Opera-
tions. Coordinates all activities and
responsibilities of the Office of Water
Program Operations^ concerned with
preparation and review of environmental
Impact statements. This Includes provid-
PROPOSED RULES
ing technical assistance to the Regional
Administrators on Impact statements and
assisting the Office of Federal Activities
In coordinating the training of person-
nel Involved in the review and prepara-
tion of NEPA-assoclated documents.
Public Affairs Division. Rtelonal
Offices. The responsibilities of the re-
gions' Public Affairs Divisions In addi-
tion to those in ) 6.110(4) are to:
(1) Assist the Regional Administrator
In the preparation and dissemination of
NBPA-associated documents.
(2) Collaborate with the Headquarters
Office of Public Affairs to analyze proce-
dures in the regions for public participa-
tion and to develop and recommend to
the Office of Federal Activities a pro-
gram to improve those procedures.
§ 6.510 Criteria for preparation of en-
vironmental Impact •tstemenls.
The Regional Administrator shall as-
sure that an Impact statement will be
prepared on a treatment works facilities
plan, 208 plan or other appropriate water
quality management plan when any of
the criteria in {6.200 apply or when:
(a) The treatment works or plan will
induce or encourage significant changes
In Industrial, commercial, or residential
concentrations or distributions, the ef-
fects of which have not been adequately
reflected In a previous impact statement
on either the facility, the section 208
plan, or other water quality management
plans encompassing the works. Factors
that must be considered In determining If
induced changes are significant Include
but an not limited to: the land area
subject to Increased development as a
result of the treatment works) the In-
creases In absolute population which
may be Induced; the increase In the rate
of change of population; changes in den-
sity; the potential for overloading sew-
age facilities,- the extent to which land-
owners may benefit from the areas sub-
ject to increased development; and the
nature of land use regulatlona in the af-
fected area and their potential effects
on the development.
(b) Any major part of the treatment
system will be located on wetlands or
parklande, or in some other way will
significantly affect wetlands or park-
lands.
(c) The proposed treatment plant
lite, eBuent disposal site, or sludge dis-
posal site is located on or adjacent to a
habitat of species listed on the Depart-
ment of Interior's list of endangered
species.
(d) The works or plan will result In a
significant displacement of population.
(e) The works or plan will have sig-
nificant adverse impacts on areas of rec-
ognized scenic, recreational, or archeo-
loglcal value.
(f) The works will affect properties
listed in or eligible for listing in the Na-
tional Register of Historical Places, only
when a memorandum of agreement
showing removal of adverse effects can-
not be agreed to by the Agency, the Stole
Historic Preservation Officer, and the
Executive Director of the Advisory Coun-
cil on Historic Preservation.
ntal Impact of*J
ghly controvenj:
(g) The works or plan >
Icantly deface an existing
area. ,.__
(h) The works or plan may """STi
or through Induced development nay'
•Ignlficant adverse effect upon local *^
blent air quality, local ambient
levels, surface or groundwater qo
fish, wildlife, their natural habitats,
other natural elements. _i«nif-
(i) The works or plan may WJS,
Icantly and adversely affect the qt»"y
or quantity of either surface or group-
water In a basin. jtf,
(J) The treated effluent Is being "Jj,
charged into a body of water where «j
present classification U being challeni,
as too low to protect present uses,,**r
the effluent will not be of sufficient n
Ity to meet the requirements of
uses.
(k) The environment!
works or plan is highly
based on environmental issues I
a concerned party or parties.
86.512 Procedure, for implement*1*
the NEPA.
(a) Environmental assessment. *jj
adequate environmental assessment"*^
be an integral part of any facu>Bf*rf,
section 208 plan submitted to the Ag«J*
The analyses that constitute an *Jj
quate environmental aneument ""
include: ---*
(1) Description ol the
without the protect. This shall
for the delineated planning area »<£j
scrtptlon of the present environni"™^
conditions when they are relevant to w^
analysis of alternatives or deternwjj
tlons of the environmental lmp«CMia4
the proposed action. In addition,"!;
future environmental conditions, ***£!*
Ing no project, shall be described. >
description shall Include but not be "»"
Ited to a discussion of water Otl*%
water supply and needs, air quality,""{;
use trends, population projection!. *•,.
lands and other environmentally r
tive areas, historic »lt*s, other :
projects in the ana, and where rw- __.,
a description of plant and animal c°3,
munltlea that may be affected, espe"*™
ra*e and endangered species. j
(1) Analysis of alternatives. TblS(»"J.
Include a comparative analysis "'"y
tlons and a systematic development
wastewater treatment alternatives. ,
reasons lor rejecting an c ' "
presented In addition to any
environmental benefit forgone by <*K»
tlon of tbe option. The preliminary ^Kf-
natives shall be screened with reap*""JJ
goal attainment, approximate mone""
costs, i)gnm*»nt environmental •*'*T,
and physical, legal or institutional «»*
stralnts. The reasons for rejecting* I**,
Jlmlnary alternative shall be •uinW'J
rized. The alternatives remaining *"J
screening shall be compared on the B»g
of detailed capital and operating <*»»
contributions to water quality goato. •£
liability and flexibility, and envlronO*"'
tal impacts, giving special attend**
long-term Impacts, irreveritb.* Hop*'*
HOHAL MOISTII, VOL 39, NO. 13*—WIDNISDAY, JWY 17, 1*74
Do.lU-Ft.nl •
HOUAL noism, voi. it, NO. us—WONHDAV, JULY 17,
-------
• ««* a. develop-
. T * thau ta o0™"
«hau elude. pment °' »"<™»u™«
•
n/Inflow reduc-
"oni andin^ W deveI°P"Pent regula-
»™e**»B(
'ng wast™?. and discharge, includ-
»*teTr£ha±reUSe (in*»"-«". iroiind-
«'*anceraenu ',°rHSurface water ™™1Y
«°n. ovSand n0and W^'ion (Irriga-
'"•eatmentIproc °T percolation) • and
«al1VwSS*>sfJ °' '.'"dee and other resld-
Ung process options
"""•tta such as land
in. and landfill
: of facilities;
, "» wallty
efflclen' operation and
"Delated with
°' °P"on8 "hau
s°urce TOntooE* ™nt"*i. non-point
r«n«emen£r wd """tutlonal ar-
??fnt "actlces.
'lL lm*»xt, ol the vro-
j ThU .hall Include .
Z °' °* «»vlronmen-
1 "native will
m. ta «">. Paid to induce
»owth. BoPWatlon patterns and
fwquatel, surfS. tld on the Plan will
— !lMed* wItrXenvlronmentsl
A» "'he" &&££**S***"***"*-
ftfaiT-Sastfjuraft
PROPOSED RULES
(O Environmental review.—(11 Gen-
eral. All facility and section 208 plans
submitted to the Agency will be reviewed
to determine the adequacy of the Integral
environmental assessment and to deter-
mine If the plan will have any significant
environmental Impacts. If any changes
can be made in the project to eliminate
or mitigate their impacts, and II an
Impact statement is required.
(1) If the Integral assessment does not
meet the requirements of { 6.512(a>, the
plan shall not be approved. If deficiencies
exist, they shall be identified In writing
by the Regional Administrator and must
be corrected before the plan can be
approved.
(U) To determine If the plan will have
any significant environmental Impacts
requiring an impact statement, the plan
shall be reviewed in accordance with the
criteria in I 6 200 and i 6.510. Either a
notice of Intent and Impact statement or
a negative declaration and environmen-
tal appraisal must be prepared on each
facilities and section 208 plan.
(2) Historic sites. If a facilities or
section 208 plan may affect a property
listed In or eligible for listing In the Na-
tional Register of Historic Places, the
submitter of the plan shall consult with
the State Historic Preservation Officer to
determine If the effect will be adverse. A
no-effect determination shall be docu-
mented In a memorandum to be sub-
mitted with the facilities or section 308
plan. If the project will have an adverse
effect, the submitter of the plan shall at-
tempt to develop alternatives with the
State officer to remove or mitigate the
adversity, and prepare a proposal for a
memorandum of agreement. The memo-
randum shall be Included with the fa-
cilities or section 208 plan submitted for
approval. If a proposal for a memoran-
dum of agreement cannot be developed,
the reasons shall be explained In a mem-
orandum to be submitted with the facu-
lties or section 208 plan. In such cases,
the Regional Administrator shall com-
mence consultation with the same offi-
cials In accordance with I 6.214 (a) In an
attempt to come to an agreement. If this
consultation Is unsuccessful, the Re-
gional Administrator shall prepare an
Impact statement as required by
!6.510(g).
(.31 Wetlands. If the facilities or sec-
tion 208 plan may affect wetlands, the
Regional Administrator shall follow the
procedures described In I6214(b).
(4) ruh anil wUtlife. If the facilities
or section 208 plan may result In the con-
trol or modification of any stream or
other body of water, the Regional Ad-
ministrator shall follow the procedures
described In I 8.214 Interim procedures.—<1> General.
Until facilities plans are required, an
environmental assessment meeting the
requirements of ft 6.513 (a) shall be sub-
mitted with the application for each
step 2, 3, 2 and 3, and 2/3 grant. How-
ever, when a step 2 grant application
Is received the NEPA procedures mutt
always be completed before awarding the
step 2 grant except as provided in
8 6.504(a) (5). In such cases, an assess-
ment is not required with the step 3
grant application and the NEPA decision
need not be made again. The assesment
should be reviewed In accordance with
S 6,5l2(c> to determine If It Is adequate
and whether an impact statement should
be prepared. If the assessment Is not
adequate, the deficiencies shall be identi-
fied In writing by the Regional Admin-
istrator and must be corrected by the
grant applicant before the Regional Ad-
ministrator can act on hla application.
The Regional Administrator is respon-
sible for determining the proper scope
of the review to ensure that the cumula-
tive impact of Individual works Is prop-
erly evaluated. If any water quality
management plans are available for the
ana, they should be considered in de-
termining the proper scope of the review.
If an Impact statement Is to be pre-
pared, ft notice of intent will be prepared
as described in 1 8.Bl2(d>. If appropriate,
the Regional Administrator may prepare
an Impact statement on a number of
related grants or an available water
quality management plan. If no Impact
statement need be prepared, a negative
declaration should be prepared in ac-
cordance with ft«.B12 "Appropriate program official."
The official within the ORD to whom the
responsible official delegates most of the
work related to compliance with NEPA.
26263
(f) "Decision official." The Individual
rwponaible for determining If a proposal
for conducting a specific project will be
funded. The assignment of this role will
vary According to cost and subject
matter.
(g) "TfSPA-tatoctated documents.'
Notice of Intent, negative declarations,
environmental appraisals, news rdeeaen,
Impact statements, and assdeenienta.
fi 6.604 Applicabttitr.
(a) Adminitrativff action* covered.
This subpart applies to the administra-
tive action* listed below:
(1) Approval of PAP's, except for those
PAP's excluded In paragraph (b) CD of
tbip section ^
(2) Approval of ROAP's, except for
those ROAP's excluded In paragraph
(b)(2) of this section;
(3) Award of a contract or grant on
projects (tasks), except for those ex-
cluded In paragraph (b) (3) of this
section;
(b) Administrative action* excluded.
The Agency actions listed below are not
subject to the requirements of this part.
However, none of these actions are ex-
cluded from the procedures on historic
sites, wetlands, or nan and wildlife de-
tailed in 16.214.
(1) Approval of PAP's developed pur-
suant to the Federal Water Pollution
Control Act (FWPCA) Amendments of
1872;
(2) Approval of ROAP's developed
pursuant to the FWFCA Amendments of
1872;
(3) Award of a contract or grant on
tasks undertaken pursuant • to the
FWPCA Amendments of 1972.
These exclusions are consistent with
section 511(c) U> of the PWPCA Amend-
ments of 1972.
g 6.606 RetponaibUlies.
(a) Responsible official. The respon-
sible official for Agency actions covered
by this subpart is the Assistant Adminis-
trator for Research and Development.
The Assistant Administrator will dele-
gate most of the work to the appropriate
program official. The responsibilities of
the responsible official, in addition to
those in !6.1lO(a>, are:
(1) Ensures that environmental as-
sessments are submitted and the appro-
priate program officials conduct environ-
mental reviews, prepare Impact state-
ments and other NEPA-asaociated
documents, and take such subsequent
actions as are delegated to them by the
responsible official.
(2) When projects significantly affect
more than one regional office, are highly
controversial, are of national signifi-
cance, or "pioneer" Agency policy, the
appropriate program official shall co-
ordinate the project with the Office of
Program Integration, Assistant Admin-
istrator lor Research and Development.
(b) Assistant Administrator. The re-
sponsibilities of the Office of the Assist-
ant Administrator as described In f 0.110
(e> shall be assumed by the Assistant
PCDCRAL UOISTM, VOL. 39, NO. tsi—WIDNHDAY, JULY 17, 1974
FEDERAL REGISTER, VOL. 39, NO, US—WEDNESDAY, JULY 17, 1974
-------
26264
Administrator for Research and Develop-
ment for Agency actions covered by this
subpart.
Office at Program Integration,
Assistant Administrator lor Research
and Development. Advises trie Assistant
Administrator for Research and De-
velopment, concerning projects which
significantly affect more than one
regional office, are highly controversial.
are of national significance, or "pioneer"
Agency policy, when these projects have
had or should have had an environment-
al Impact statement prepared on them.
(d) Regional Administrators. The re-
sponsibilities of the Regional Adminis-
trator with regard to projects of the
Office of Research and Development
which affect his legion will be to:
(1) Provide technical and administra-
tive assistance in environmental reviews
and in the preparation of Impact state-
ment!.
(2) Advise the appropriate program
officials and the Office of Program Inte-
gration of any projects which will signifi-
cantly affect more than one regional
office, are highly controversial, are of na-
tional significance, or "pioneer" Agency
policy, when these projects have had or
should have had an environmental im-
pact statement prepared on them.
{ 6.608 Oil,™ /or tnc preparation of
environmental impact Mulemrnl,.
(a) An Impact statement shall be pre-
pared and processed by the Office of Re-
search and Development when:
(J) The action will have significant
adverse Impact* on public parks, wet-
lands, wildlife habitats, or areas of rec-
ognized scenic or recreational value.
(2) The action will have significant
adverse impact* on area* of recognized
archeolqglcal value.
(3) The action will adversely affect
properties listed in or eligible for listing
in the National Register of Historical
Places, only when a memorandum of
agreement showing removal of such ef-
fects cannot be agreed to by the Agency,
the State Historic Preservation Officer,
Mid the Executive Director at the Advi-
sory Council on Historic Preservation
M> The action will significantly de-
face an existing residential area.
(5) The action may directly or through
Induced development have a significant
adverse effect upon local ambient air
quality, local ambient noise levels sur-
face or groundwater quality, fish, wild-
life, their natural habitats, or other nat-
ural elements.
(8) When the treated effluent is being
discharged Into a body of water where
the present classification is being chal-
lenged as too low to protect present uses
and the effluent will not be of sufficient
quality to meet the requirements of such
uses,
- C3> The project consists of field tests
Involving the Introduction of agricul-
tural chemicals, animal wastes, pesti-
cides, radioactive materials, or other haz-
ardous substances Into the environment
by the Office of Research and Develop-
ment, Its grantee, or its contractor.
PROPOSED RULES
(8) There Is a high probability of an
action ultimately being implemented on
a large scale and the broad scale applica-
tion may result In significant Impact* on
the Immediate area in which it will be
located.
(9) The commitment to a new tech-
nology is relatively significant and may
restrict future viable alternatives.
(10) The environmental impact of a
project is highly controversial based on
environmental Issues raised by a con-
cerned party or parties.
(b) An impact statement* will normal-
ly not be necessary when:
(1) The project is conducted com-
pletely within a laboratory or other fa-
cility, and external environmental effects
have been minimized by providing effec-
tive methods for disposal of laboratory
wastes and effective safeguards to pre-
vent accidental Introductions of hazard-
ous materials into the environment; or
(2) The project is a relatively small
experiment or investigation that is part
of the private sector, and the project
makes no significant new or additional
contribution to the existing pollution.
§ 6.610 Procedures for compliance vilh
NEPA.
BIS related activities shall be inte-
grated into ORD's formal research plan-
ning system. The planning system en-
sures management control of all research
and development actions assigned to the
ORD. In this planning system, all incre-
ments of work are interrelated by means
of a hierarchical system of planning doc-
umentation (tasks, ROAP's, and PAP's).
The PAP is the highest level plan whose
output synthesizes a subordinate set of
ROAP's. A ROAP includes and amalga-
mates a group of tasks and represents
a multiple-year effort. The task or proj-
ect is a manageable unit of research
activity directly supervised by a single
project Individual. The ROAP's and
PAP's are available to all management
levels and can only be modified by formal
change procedures. These plans are re-
viewed by ORD management on an an-
nual basis as a minimum. At this nine
all subordinate plans arc reevaluated,
new RfcD Initiatives considered and
priorities and resources recommended to
the Agency.
(a) environmental assessment. (1)
Environmental assessments shall be sub-
mitted to the Agency on certain extra-
mural projects (tasks), including all
grant applications and proposals for sole-
source contracts. Jn the case of com-
petitive proposals, assessments need not
be submitted by potential contractors be-
cause the NEPA procedures will be com-
pleted before a request for proposal
(RFP) Is Issued. If there is a question
concerning the need for an assessment,
the potential contractor or grantee
should consult with the appropriate offi-
cial responsible for the grant or con-
tract.
(2) The assessment shall contain the
same sections specified for Impact state-
ment! In 10.304. Copies of 16304 (or
more detailed guidance when available)
and a notice alerting potential grantees
and contractors of the assessment re-
quirements shall be included in all grant
application kits, attached to letters con-
cerning the submission of unsolicited
proposals, and included with all requests
for sole-source proposals.
(b) Environmental review—(1) PAP's.
An environmental review shall be con-
ducted for all PAP's that are not listed
in 5 6.604(b), prior to their Incorporation
Into the ORD annual program plan. This
review will consist of an evaluation of the
potential environmental effects of the
efforts proposed within the PAP's. The
criteria In I 6.608 shall be used to deter-
mine if these effects may be significant.
(i) The environmental reviews for
continuing programs will be reevaluated
annually to coincide with the ORD plan-
ning cycle and at any other time when
a major change In objectives Is officially
incorporated.
(ii) Current PAP's, less budgetary
data, will be filed with the Office of Pub-
lic Affairs project."
A project undertaken with resources
ether than grant or contract funds
(2) "Extramural project." A project
undertaken with grant or contract funds.
(b) "Project officer." The Individual
responsible for the technical direction
and evaluation of a grantee's or contrac-
tor's perf onnanoe.
(c) "NEPA-aisaciated documents"
Notices of Intent, negative declaration!,
environmental appraisals, news releases
impact statement!, and assessments.
§ 6.704 Applicability
This subpart applies to those actions
specified in 8 6.106(a) (5) and (6) that
are undertaken by the Office of Solid
Waste Management Programs. The spe-
cific procedure! to be followed for various
project types are let forth In 5 6.710.
9 6.706 RuponaOu'lltiei.
(a) Responsible official. The renHmaf-
ble official for Agency action* covered by
thl* subpart Is the Deputy Assistant Ad-
ministrator for Solid Waste Management
Programs. The *e«ponslbllltlei of this re-
sponsible official. In addition to those in
16.11o(a) are:
(1) Insure that environmental assess-
ments are submitted by appropriate
grant and contract applicant*, and that
project officers conduct environmental
reviews on all project! and take such
•ubseqaent action* aa are delegated to
them by the "rawonsible offlclaP
.. '?> A*8"* *b» Office of Federal Ac-
tivttle* to coordinating the training of
personnel involved in the review and
Preparation of all NEPA-aMociated
documents. <~»«~
tor/or**'1*' *"" A*8l*Unt Admlniitra-
oerntng project! which «lgmfleanay°a?
feet more than one ««rt™«.i --.Tr
highly
(b)
„,
tlonally significant, or "pioneer" Agency
(Wiley.
(2) Assist the reeponafble official in
UK preparation and distribution of
NlSPA-auoclated documents.
§ 6.708 Grilerii for Ike preparation of
environmental aMCMmenU and im-
pact ilitemenu.
(a) Assessment preparation criteria.
Environmental assessment need not be
submitted wltb all grant applications and
contract proposals. Studies and Investi-
gations do not require assessments. The
following section! describe for other ac-
tion* when an assessment Is or Is not re-
quired:
(1) Grants — (i) Demonstration prot-
ects. Environmental assessments must be
submitted with all application* for dem-
onstration grant! that will Involve con-
struction, land u*e (temporary or per-
manent), transport, sea disposal, any
-
seannenti. A detailed analysis of environ-
mental problem* and effect! should be
part of the planning proceea, however.
(2) Contract*.—(1) Sote-sovree co*~
tract proposals. Before a sole-source con-
tract can be awarded; an envlronmentjj
assessment must be submitted wltb a j"°
proposal for a contract which will in-
volve construction, land use (temporary
or permanent), sea dtapouU, any d»-
charges into the air or water, or anr
other activity that will directly or str
directly affect the environment external
to tne facility in which the work will **
performed.
Ui> Competitive contract prapow>'
Assessments will not generally be *f
oulred on competitive contract propo***;
(b) Impact statement prepare***
criteria. An environmental review «**J!
be performed on those project! of *»•
Office of Solid Watte Management tV
grams on which an •saeeament 1! **"
quired or which may have effect! on **
environmental external to the facUM* *
Crf *" to l"3W
-"JI
(a.T^ro.^,,
».
«>
**" commenu
amplffle. the
a questio
COntr"cl0r
KDMAL M6I5TII, VOL 39, NO. 13»—WfDNfSDAY. JUU )7, 1474
HDIIAI neitm. VOL j», NO. ut-wiDNUDAr. jwr ,r.
-------
28268
<2> The assessment shall contain the
•am* sections specified for Impact state-
™mt<«f I «-»04. Copies of 18.304 (or
more detailed guidance when available)
and a notice alerting potential grantees
"fcoutracton of the assessment re-
S™"™?*" In 16.708 shall be Included
l.ta:L(rant application kits, attached to
JJSl'J'JonoernIng the submission of un-
r-r™*f Propcsal!, and Included with all
Wfluesta for proposals (RFfs).
rani! ^"toanmental rertem. An envl-
™»»ntal review will be conducted on
*h£?PJect* whjch "quire assessment! or
terrS ,**? •"•»' the environment ex-
S»I to the facility to -which the work
Woduetedfij}""1 Thto IOTlew mu*t "*
JSJJ i°»deon extramural project! or
"wore prolAnt WW*»M«,.,,M«.^-« «_t—.
ttral . -
wnib. SK wta- Tbe Adeline, to 1 6.JOO
•ot w«{ "JJ?*1 to °**™talng U the proj-
assessment by both
the appro-
- -
comments will In-
"oonunendationi on the need
^S01*111 ""W*4 statement
I**l?w « documentation X
a* J?°J«ct« (or which as*»-
not a««M .?°* ™>ul»d and which win
'•oll ** •OTlr«™>ent external to a
H any of tbe
• the responsible
. i •
West thea\,SS2^bl« """"a" •""I »•
1 Admlnto-
not b
aa may
a* wec-
ton and enriron-
apprafial. 11 the envlnm-
~ ' ' that there win
environmental
an environ-
•Wired taoltcf°?m'*™*ment. A. re-
•*an not bJ ai^i,contraot " •*•»*
Project, nor al . f3 on *" "tramural
w™.unttlfl«i? taf£»n>ural project be-
of J rj" ***fc«sii (16) days after mlc-mo
Impact atate-
Omce of Solid
>ho™
ure, described
PROPOSED lUUS.
in Subparti A through D by providing
detailed procedures for tbe preparation
of Impact statements on construction and
renovation of special purpose facilities.
16.801 Definition..
(a) "S]McWmrj>Me/acUttv."Abulld-
inc or ipece. <^>^y!*ng land tnridfrnial to
tbe use thereof, which Is wholly or pre-
dominantly utilised for the special pur-
poee of an agency and not generally suit-
able for use for other purposes, as de-
termined by the General Services Ad-
ministration.
(b) "Provram of requirements." A
comprehensive document (booklet)
describing program activities to be ac-
complished in the new special purpose
facility or improvement. It includes
architectural, mechanical, structural,
and space requirement*.
(o) -Scope ol work." A document simi-
lar to content to the program of re-
quirements but substantially abbre-
viated. It to usually prepared for small-
Kale project!.
| 6.804 Applicability.
(a) Actiom covered. These guidelines
apply to all new special purpose faculty
construction, activities related to such
construction (e.g., site acquisition and
clearing), and any Improvement! or
yn^tflratilffn! to such facilities having
potential environmental affect* external
to the faculty. This Includes new con-
struction and Improvement* undertaken
and funded by the Facilities Manage-
ment Branch, Faculties and Support
Services Division, Office of Administra-
tion; by a regional office; or by a Na-
tional Xnvlronmental Research Center,
(b) Action* excluded. This subpart
does not apply to those activities of the
Facilities Management Branch. Facili-
ties and Support Services Division, for
which the branch does not have full
fiscal responsibility for the entire project.
This Include! pilot plant construction,
land acquisition, site clearing and access
road construction where the Facilities
Management Branch'! activity Is only
supporting a project financed by a pro-
gram offiee. Responsibility for consider-
ing the environmental Impacts of such
project! rests with the office managing
and funding the entire project. Other
subparta of this regulation would apply
depending on the nature of the project.
16.806 RespoasIMllBcs.
(a) RetponriNt ofMal. The respon-
sible official for new construction and
modification of special purpose faculties
Is as foDows:
<1> The Chief, Faculties Management
Branch, Data and Support System! Divi-
sion, shall be the responsible official on
all new construction of special purpose
facilities and on all Improvement and
modification project! for which the
Facilities Management Branch has re-
ceived a funding allowance.
(1) The Regional Administrator shall
be the responsible official on all Improve-
ment and modification project! for
which the regional office has received the
funding allowance.
(3) The Center Director shall be the
responsible official on all Improvement
and modification projects for which the
National Environmental Research Cen-
ters have received tbe funding allow-
(b) The responsibilities of the respon-
sible official! specified above, in addition
to those In I «.110(a). are as follows;
(1) Ensure that environmental as-
sessment! are submitted when re-
quested. tnat environmental reviews are
conducted on all projects, and Impact
statement* an prepared and circulated
when there will be significant impacts.
(2) Assist tbe Office of Federal
Activities In coordinating the training
of personnel Involved In the review and
preparation of NEPA-ftMoclated docu-
ment!.
I 6.801 Oiterla for the prepar .tlon ol
environment.! «MMnMntt and Im-
pact statements.
(a) Aitetsment preparation criteria.
An environmental assessment may be
requested of a construction contractor
ox consulting architect/engineer em-
ployed by the Agency u they are involved
In the planning or construction of special
purpose facilities or m modifications to
such facilities having potential environ-
mental effects external to the' facility
Such modification! Include tut are not
limited to: facility addition!, change! In
central heating system! or wsstewater
treatment systems, and land clearing for
access roads and parking lots.
0» Impact itatement preparation
criteria. An environmental review shall
be performed on all actions Involving
construction of special purpose faculties
and on Improvements to such facilities
The guidelines set forth hi I 8.200 shall
be utilised to determine whether an Im-
pact statement shall be prepared.
' 6-812,n5VoM
-------
26268
I. Applicant submits environmental as-
aeanment ft*vt other available date.
a. Agency perform* environmental review
at Ui« earliest possible point In the devel-
opment of the propoeed action, decides tt an
ETS la required, prepares an WIS tt the pro].
ect will have a significant Impact or if tb*
project's Impact is likely to b* highly con-
troversial.
8. Where required, prepare environmental
Impact appraisal.
4. Prepare and circulate negative declara-
tton to Federal, State, and local agendas,
aud where practicable to Interested persona,
local newspapers, and other media. This may
b* supplemented by making It available
through local librarian or post offices.
6. FUe Impact appraisal, negative deelara-
tlon. and other supportive document* m-
houae. ( Available for public Inspection.)
6. Receive and evaluate comment*.
7. Change decision, if necessary.
8. Administrative action.
9. Prepare, notice of Intent.
10. Circulate notice* of Intent.
a. Regional Bluff,
b. Office of Federal Activities
c, Appropriate headquarter* program office
JOS Coordinator.
d. Office of Public Affair*.
e. Office of Legislation,
f. Federal agencies.
g. mate and local agencies, appropriate
Btete, regional and metropolitan deartng-
bouaea.
h. Intereated person*.
1. Newmpapen and other media as appro-
priate.
11. Prepare preliminary draft envlronmen-
tal impact statement and summary sheet.
a. Description of toe proposed action.
b. environmental Impact of the proposed
action.
o. Advene effects which, cannot be avoided
should the proposal b* implemented.
d. Alternative* to the propoeed action.
e. Relationship between local abort-term
n**s of man's environment and the mainte-
nance and enhancement of long-term pro-
ductivity.
f. Irreversible and irretrievable commit-
ment* of reaounjas which would be Involved
ID tb* proposed action should it be imple-
mented.
g. A discussion of problem* and objection*
ni*ed by other Federal. State, and looal
agencies, and by private organization* and
individuals to data.
19. Coordinate Internally for review and
comment with appropriate regional and
headquarters (optional) elements.
19. Bvaluato comment* and revise prelimi-
nary draft awarding! j.
14. Notify OFA and appropriate bemdquar-
t*fs program office US coordinator of Intent
to rtlamts draft.
IB. Submit draft for review.
a, OFA (2 copies).
b. Appropriate bsadquarten program offica
IIS coordinator (3 oopias) .
16. Conatder eomtnente and revise draft
accordingly.
,17, Prepare transmitteJ Istter with n-
sponsibl* official's signature.
18. Submit news release to local newspaper*
and otter media (on* copy) .
»- Distribute draft and toMumtttal letter
externally for rtvltw and comments.
a. Council on environmental Quality (6
b. Notify Offlee of LeglBlatton of release,
( copies a* needed) .
c. Notify Offlce of Public Affairs of release-
(two copies).
d. Offics*. of appropriate Federal agencies
( two eopte* unlee* mot* an requested) ,
*. Appropriate State and total Minilm
appropriate State and mstropolltan cJeartng-
hOUSSS (tWO OOpleS) .
PtOPOSB) BULK
f. Interested parsons (one oopy).
g. Forward summary sho«t to OUB-OseBO
(twooopU*).
aa. Regional staff.
bb. Public Attain Division if prepared IB
region (copies as needed).
oc. OVA (two copies).
ad. Appropriate headquarters program of-
fice ma coordinator (two copies).
20. Dfrtermln* need for public hearing.
31. Circulate public notice.
99. Conduct public hearing.
38. Review and evaluate suggestions,
criticisms and comment* received and re-
examine the proposed course • of action, and
alternatives. Include evaluation of comments
generated at public hearing* (tf held).
34. Prepare final environmental Impact
statement.
30. Submit news release to looal newspapers
and other media (one copy).
itt). Distribute final to Interests submitting
comments on draft (one copy).
a. Council on Environmental Quality (9
copies),
b. Notify Office of Legtelatton of release
(copies M needed).
o, Notify Offlce of Public Affairs of release
(two copies).
d. Forward summary to OMB-OMBC (two
oople*).
aa. Rogion&I staff.
bb. Public Affairs Division If prepared la
region (copies a* needed).
oo.OFA (twocopies).
dd. Appropriate headquarters program of-
fice MB coordinator (two copies).
37. Administrative action.
EIKOIT if
Mono OF INTENT TRAKBHITTAL If
stroaxsntD FOBIUT
(Date)
•HVXXONMEHTAL nOTBCTIOK AOKNCT,
(Appropriate once)
" (Add^eY, cftT.Vuti.
Zip Code)
To All Inttraettd Oowrnment Agtnelm did
PubUo Group*.
OflDUftmMi: In Moarduuw with tlu gnlde-
llnM (or th« impuatlon o( anlroniuntal
Unput iteteountt. >ttacb«l to » notlos ot
Intent to pnpm iuch > itatonunt lor ttu
proposed Agcncr action •p^lflad below:
(Official Project Name)
•V Bstbnated project oosfe
Federal Share (total) «,
Contract« Grant > Other f - J_
Applicant chare (tf any):
(Name) .- „. _„ $ „
Other (specify) *
Twtal - *
8. Period covered by project:
Beginning date
(Original date, If project
covers more than one year)
Date* of different project phases
Approiimate ending date
4. Estimated application filing date ___
NIDM SILXMI SrroOESTBB FOSBU.T
MOTICK TO TBS mLIO r«OU TH> EWTOtOH-
MENTU. raOTXCTIOK AOIMOT
This announcement 1* to inform the pub-
lic that the Xnvlronmental Protection
Agency (originating office, address) (will pre-
pare, will not prepare, ha* prepared) a (draft.
final) environmental Impact statement on
the following project:
(OfflclaT Project Name)"
(Purpose of Project)
(Project Location, City, County. State)
(Where statement can be obtained if one Is
prepared)
This notice is to implement the Agency's
poUoy to Inform the public to the mir^mnm
possible extent of environmental actions It is
taking.
EXHIBIT 4
PKCUKATIOM •TKHHSTXD VOBHAT
(D»tt)
(AppropttH.Offlc.)
"(iadr«>«7ottj" sit*. Zip Code)
To An InUn*Ud Oonrnment Ag«nol«» uid
Public Oroup«,
a«ntlttmeti: Xn •coord with th* prooBdurw
for tlu mpMtlan al «nrtronni«nt«l Imput
vtetemt&te, m oBvlMininnital rarlew hM
been perform** OB the propoMd Agency no-
tion below:
(Official Project Natoe)
If your organization needs artrtltlnnal In-
formation or wUbes to uaiUulpate In the
preparation of the draft environmental Im-
pact statement, please edvl** th* (appropri-
ate, office, city, State) .
Very truly yours,
City. County, State)
(Speoiflo Project
Location— provide either
a map or description)
(Appropriate BPA Ottos)
(List Federal, Btate, and local agendas to to
solicited for comment.)
(Uet publlo action groups to b* solicited for
Nones or XmnMT—Svooem FOBMAC
I. Project location:
After making «n environmental renew of
tt* projieet, ttris Jasjaaey be* deeMed not to
prepare an ssumeaimsntal impact steAement.
An environmental isnpaot appraisal, which
•uinmariees the larvlaw and th* reason* why
astaiemen*tease>reojulred,sionaieatthe
and wflt be avaUable for publlo
with thto OcMon may
for oon*id*r»Uon by the
HOHAl MBItm VOL If, MO, TJi—WIOMKOAT, JUNT t*. 1f*«
Agency. The Agency will not take any ad-
ministrative action on the project for at least
fifteen (16) days after release of this negative
declaration.
Sincerely,
PROPOSED RULES
8. Agencies consulted about the project:
(Appropriate EPA Official)
EXHIBIT 6
State representative's name: m.
Local representative's name:.
OTHER:
A. Identify Project
Name of Applicant:
Address: —
Project Number {if assigned):.
B. Summarize Awesement.
1. Brief description of project: —
C. Reason* for concluding there~will"be"no
significant impacts.
(Discuss topics 9, 9, 5, 6, and 7 above, and
how the alternative (topic 4) aeleeted will
avoid any major publlo objection* or signifi-
cant Impact*, thereby making an Impact
statement unnecessary.)
(Signature of appropriate
official)
3. Probable impact of the project on the
environment:
(Date)
3. Any probable adverse environmental ef-
fects which cannot be avoided:
4. Alternatives considered with evaluation
of each: .
6, Relationship between local abort-term
UMS of environment and maintenance and
enhancement of long-term productivity:
fl. Any irreversible and irretrievable com-
mitment of resource*:
COVK* BHKET FORMAT FO« XHVDtONMEMTAL
IMPACT STATEMENTS
(Draft, Final)
Environmental impact Statement
Prepared by
Approved by
t. Public objection* to project, H any, and
their resolution:.*.,_,.
(Describe title of
project or plan)
(Responsible Agency
.Offlce)
(Responsible Agency
Official)
(Check One)
( ) Draft
( J Final environmental Statement.
EHVnoNMENTAl. PKOTBOTIOlf AOKWOT
(Responsible Agency
Offlce)
1. Name of action. (Check one)
( ) Administrative action.
( ) Legislative action.
a. Brief description of action Indicating
what State* (and counties) are par-
ticularly affected,
3. Summary of environmental Impact and
adverse environmental effects,
4. List alternatives considered.
ft. a. (For draft statements) List all Fedsrai-
State, and local agencies from whicD
comment* have been requested.
b, ('For final statement*) Ltet all Fed***1'
State, and looal agencies and otft*r
sources from which written comnwnt*
have been received.
6. Dates draft statement and final *tatemsnt
made avaUable to Council on Envlronmen*
tai Duality and public.
TOftAl U01ITM, vot at, NO. Ug—WtDMUDAr, JULY 17. 1*74
-------
26270
PROPOSED RULES
UMMM
rimiAiT r«i ism
i IM Mitmum'g AN m H UQ»M» ON MVMW NHMKH
IFB Dot.74-16128 Filed 7-l«-74;a:« »m]
HDIIAL liaifTK. VOL 19, NO. U«—WIONISDAY, JUIV 17, 1974
10
-------
i
I
•*•
M
TERRESTRIAL WILDLIFE OF THE REGIONAL AREA
Fauna
The discussion that follows is based on the checklists of amphibians,
reptiles and mammals given by W. G. Bradley and J. E. Deacon (1967).
Species'jijiscuS'Sed by Bradley and Deacon were crosschecked with R. C.
Stebbins (1966) and Burt and Grossenheider (1964) to verify that their
range includes the study area. All scientific names are based on
Stebbins (1966) and Burt and Grossenheider (1964).
-------
Common Name
Scientific Name
Creosote
Saltbrush
Biotic Community
Desert Riparian
Las Vegas Wash
Other
Amphibians
Great plains toad
Red-spotted toad
Southwestern toad
Woodhouses's toad
Canyon tree frog
Pacific tree frog
Bullfrog
* Vegas Valley
leopard frog
Leopard frog
Grear basin
spadefoot
Reptiles
* Desert tortoise
Soft-shel1
turtle
Banded gecko
Zebra-tailed
lizard
Collared lizard
Leopard lizard
Desert iguana
Desert horned
lizard
Chuchawalla
Bufo cognatus
Bufo punctatus
Bufo micrpscaphus
Bufo woodhouseT
HyTa ¥renicol6F
tfyla jregilla
Rana ^atesbeiana
Ran a fishirT
Rana pjpiens
Scaphiopui
intermontanus
Gopherus
agassizl
Trionyx ferox
Coleonyx
variegatus
Callisaurus
dracpnoldes
Crbtaphytus
conarls
Crotaphytus
wlsiizeni'
Dipsosaurus
"
Phrynosoma
ryi
at
piatyrninos
Sauromalus
obesus
Un common
Un common
Abundant
Common
Common
Common
Abundant
Common
Record
Record
Record
Record
Abundant
Abundant
Record
Common
Record
Record
Tom Harper
Tom Harper
Tom Harper
B & N, 1972
Tom Harper
B & N, 1972
Record
Undocumented
record
B & N, 1972
Record
B & N, 1972
B & N, 1972
B & N, 1972
12
-------
Common Name
Scientific Name
Creosote
Biotic Community
Saltbrush
Sagebrush lizard
Desert spiny
lizard
Western fence
lizard
Western brush
lizard
Tree lizard
Side-bloched
lizard
Desert night
lizard
Western whiptail
* Gil a monster
Western blind
snake
Glossy snake
Night snake
Common king snake
Western s hovel -
nosed snake
Coachwhip
Stripped whip-
snake
Spotted leaf-
nosed snake
Pacific gopher
snake
Western patched-
nosed snake
Western ground
snake
Sceloporus
graciosus
Sceloporus
magi-ster
Seel oporus
occidental is
urosaurus ^.
araciosus
Urosaurus ornatus
Uta stansiburiana
Xantusia vigil is
Cnemi dophorus
tigris
Heloderma suspectum
Leptotyphiops
numilis
Arizona elegans
Hypsiglena torquata
Lamp rope His
getul us
Chionoctis
occipital is
MasticophTs"
flayellum
Masticophis
taeniatus
Phyllorhynchus
decuratus
Pituophls m.
catenifer
Salvadora
hexalepis
Sonara
semi annulate
Common
Common Record
Uncommon
Abundant Record
Common
Abundant Record
Uncommon
Uncommon
Rare
Rare
Record
Record
Record
Rare
Record
Record
Recoru
Record
Common
Record
Common
Rare
Rare
Record
Record
Record
jii i-ao vcjjaa naan \j uiit-i
X
X
Common
B & N, 1972
B & N, 1972
X
X
X
13
-------
Common Name
Scientific Name
Creosote
Bictic Community
Sal thrush Desert Riparian
Las Vegas Wash
Other
Sonora lyre snake
Western diamond-
back snake
Sidewinder
Speckled rattle-
snake
Mojave rattle-
snake
Mammals
Desert shrew
California leaf-
nosed bat
Plllld bat
Townsend's big-
Beared bat
Big brown bat
Spotted bat
Silver-haired'bat
Red bat
Hoary bat
California myotis
bat
Long-eared
myotis bat
Small-footed
myotis bat
^inge -tailed
myotis bat
Cave myotis bat
Long-legged
myotis bat
'lima myotis bat
Trimorphodon 1ambda
Crotalus atrox
Crotalus cerastes
Crotalus mitchelli
Crotalus scutulatus
Notiosorex
crawfordi
Macrotus
call form* cus
Antrozous paThidus
Corynorhfnus
sendil
Eptesicus
Euderma maculata.
LaslonycEeris
noctivagans
Lasiurus boreal is
Lasiurus linercus
Myotis aTifornlcus
Myotis evotis
Myotis subulatus
Myotis thysanodes
otis velifer
otis volans
Myotis
yumanensis
Record
Record
Common
Common
Common
Abundant
Common
Common
Uncommon
Rare
Rare
Rare
Rare
Abundant
Rare
Rare
Rare
Uncommon
Rare
Rare
Record
Record
Record
Record
Record
Rare
Rare
Rare
Record
Common
Rare
Common
Record
B & N, 1972
B & N, 1972
Record
Rare
Rare
B & N, 1972
Rare
14
-------
Biotic Community
Common Name
Western pipistrell
Western big-
eared bat
Mexican freetail
bat
Big freetail bat
Gold-mantled
ground squirrel
White-tailed
antelope
squirrel
Round-tailed
ground squirrel
Rock squirrel
Cliff chipmunk
Charleston
mountain
chipmunk
Uinta chipmunk
Valley pocket
gopher
Desert kangaroo rat
Merriam's kangaroo
rat
Great Basin
kangaroo bat
Long-tail pocket
mouse
Great Basin pocket
mouse
Bushy-tailed wood
rat
Desert wood rat
Muskrat
Southern grasshoper
mouse
Little pocket mouse
Scientific Name
Pipistrell us
nesperus
Plecotus
townsendii
Tadarida
brasiliensis
Tadarida
molossa
Ci tell us
lateral is
Ci tell us
leucurus
Ci tell us
tereticaudus
Ci tell us variegatus
Eutamias cforsalis
Eutamias palmeri
Eutamias umbrinus
Thomomys bottae
Dipodomys deserti
Dipodomys merriami
Dipodomys mi crops
Perognathus formosus
Perognathus parvus
Neotoma cinerea
Neotoma lepida
Ondatra zibethicus
Onychomys torridus
Perognathus
Creosote
Abundant
Common
Common
Common
Common
Common
Common
Abundant
Rare
Abundant
Common
Uncommon
Abundant
Saltbrush
Record
Record
Record
Record
Common
Common
Record
Record
Record
Uncommon
Record
Desert Riparian Las Vegas Wash
Record R & N, 1972
Record
Record
Common B & N, 1972
Uncommon
Record
Record
Common B & N, 1972
Rare
Common
Abundant B & N, 1972
B & N, 1972
Uncommon
Common B & N, 1972
Other
X
X
X
X
X
X
X
X
15
longimembns
-------
Biotic Community
Common Name
Brush mouse
Canyon mouse
Cactus mouse
Deer mouse
Pinyon mouse
Western Harvest
mouse
House mouse
Porcupine
Beaver
Black-tailed
Jack Rabbit
Desert cotton-tail
Nuttall 's cotton-
tail
Coyote
Gray Fox
Kit Fox
Racoon
King-tailed cat
Stripped skunk
Spotted skunk
Long-tailed Weasel
Badger
Mountain Lion
Bobcat
Pronghorn antelope
Mule deer
Big-horn sheep
Scientific Name
Peromyscus boylei
Peromyscus crinitus
Peromyscus eremicus
Peromyscus
man 1 cul atus
Peromyscus truei
TCeithrodontomys
mega 1 otis
Mus musculus
EretFfizon dorsatum
Castor canadensis
Lepus ceTlifornicus
Syl vilagus
auduboni
Sylvilaqus
nuttalli
Conis latrans
Urocyon
cin'ereoargenteus
VuTpes macrotis
Frocyon~l^otor
Bassariscus astutus
Mephitis mepMtis
Spiloqale ip_u tori us
Mustefa frenata
Taxidea TTaxus
Felis con col or
tvnx ratus
Antilocapra
ameHcana
Odocoileus hemionus
Ovis canadesis
Creosote
Common
Common
Rare
Rare
Common
Common
Common
Uncommon
Common
Uncommon
Uncommon
Uncommon
Uncommon
Common
Uncommon
Rare
Saltbrush
Desert Riparian
Record Abundant
Record Common
Record Common
Common
Uncommon
Record Common
Record Common
Record
Common Common
Uncommon Common
Common Common
Uncommon
Uncommon
Record Common
Rare in Study area
Uncommon Uncommon
Recorded throughout Study area
Common Abundant
Las Vecjas Wash
B & N, 1972
B & N, 1972
B & N, 1972
Tom Harper 1972
B & N, 1972
B & N, 1972
B & N, 1972
B & N, 1972
B & N, 1972
B & N, 1972
B & N, 1972
B & N, 1972
Other
X
X
X
X
X
N = Bradley and Niles - 1972
See Rare or Endangered Species list.
16
-------
Fauna Expected at Specific Sites
Fauna
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Night snake R R R J
Common king snake R R K K K
Western shovel-nosed
Coachwhip
Stripped whipsnake R R R j
Spotted leaf-nosed R R R R
Pacific gopher snake R R R R
Western patched-nosed R R R R
Western ground snake R R R R
Sonora Lyre snake R R R R
Western diamond back R R R R
Sidwinder x x x x
Speckled rattle snake x x x x
Mojave rattlesnake x x x x
Desert shrew *
California leaf-nosed x x x x. x
Pallid bat x x x x x
Townsend's big-eared x x x x
Big brown bat x x x x x
Spotted bat R. R R R x
Silver-haired bat R R R R
Red bat R R R R
Hoary bat R R R R
California myotis x x x x x
Long-eared rnyotis R R R R x
Small footed myotis R R R R
Fringe-legged myotis R R R R
Cave myotis bat x x x x
Long-legged myotis R R R R
Yuma myotis x x x x
Western pipistrell x x x x x
Western big-eared x x x x x
Mexican freetail x x x x
Big freetail bat x x x x x
18
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BIRDS OF THE REGIONAL AREA
NOT FOUND IN LAS VEGAS WASH OR BAY
The following list of birds for the regional area was compiled by use of the
State of Nevada check list, and "The Biotic Communities of Southern Nevada",
W. G. Bradley and J. E. Deacon, and a list provided by Mr. Charles Lawson.
21
Artie loon
(Gavia artica)
Brown Booby
(Sula leucogaster)'
Magnificent Frigatebird
(Fregata magnificens)
Louisiana Heron
*Hydranassa tricolor)
Least Bittern
(Ixobrychus exilis)
Black Brant
(Branta nigricans)
White-fronted Goose
(Anser albifrons)
Ross' Goose
(Chen rossii)
Fulvous Tree Duck
(Dendrocygna blcolor)
Surf Scoter
(Melanltta perspicillata)
Harris' Hawk
(Parabuteo unicinctus)
Bald Eagle
(Haliaeetus leucocephalus)
Purple Gallinule
(Porphyrula martinica)
Ruddy Turnstone
(Arenaria interpres)
Sanderling
(Crocethia alba)
Band-tailed Pigeon
.(Columba fasciata)
Rock Dove
(Columba livia)
Inca Dove
(Scardafella inca)
Yellow-billed Cuckoo
(Coccyzus americanus)
Groove-billed Ani
(Crotophaga sulcirostris)
Screech Owl
(Otus asio)
Snowy Owl
(Nyctea scandiaca)
Flammulated Owl
(Otus flammeolus)
Pygmy Owl
(Glaucidium gnoma)
-------
Pigeon Hawk
(Falco columbarius)
Ring-necked Pheasant
(Phasianus colchicus)
Chukar
(Alectoris graeca)
Turkey
(Meleagris gallopavo)
Sandhill Crane
(Grus canadensis)
Gilded Flicker
(Colaptes chrysoides)
Gil a Woodpecker
(Centurus uropygialis)
Acorn Woodpecker
(Melanerpes formicivorus)
Williamson's Sapsucker
(Sphyrapicus throideus)
Hairy Woodpecker
(Dendrocopos villosus)
Downy Woodpecker
(Dendrocopos pubscens)
Wied's Crested Flycatcher
(Myiarchus tyrannulus)
Olivaceous Flycatcher
(Myiarchus tuberculifer)
Least Flycatcher
(Empidonax minimus)
Saw-whet Owl
(Aegolius acadicus)
Whip-poor-will
(Caprimulgus vociferus)
Anna's Hummingbird
(Calypte anna)
Allen's Hummingbird
(Selasphorus sasin)
Calliope Hummingbird
(Stellula calliope)
Yellow-shafted Flicker
(Colaptes auratus)
Dipper
(Cinclus mexicanus)
Canon Wren
(Catherpes mexicanus)
Catbird
(Dumetella carolinensis)
Brown Thrasher
(Toxostoma rufum)
Bendire's Thrasher
(Toxostoma bendirei)
Curve-billed Thrasher
(Toxostoma curvi rostre)
Varied Thrush
(Ixoreus naevius)
Wood Thrush
(Hylocichla mustelina)
Gray-cheeked Thrush
(Hylocichla minima)
22
-------
Hammond's Flycatcher
(Empidonax hammondii)
Gray Jay
(Perisoreus canadensis)
Steller's Jay
(Cyanocitta stellerl)
Black-billed Magpie
(Pica pica)
Clark's Nutcracker
(Nucifraga columbiana)
Mountain Chickadee
(Parus gambeli)
Plain Titmouse
(Parus inornatus)
Pygmy Nuthatch
(Sitta pygmaea)
Hermit Warbler
(Dendroica occidental is)
Cerulean WarbTer
{Dendroica cerulea)
Grace's Warbler
{Dendroica graciae)
Blackpoll Warbler
(Dendroica striata)
Ovenbird
(Seiurus aurocapillus)
Northern Waterthrush
(Seriurus noveboracensis)
Veery
(Hylocichla fuscescens)
Gray Viero
(Vireo vicinior)
Yellow-throated Vireo
(Vireo flavifrcns)
Black-and-white Warbler
(Mniotilta varia)
Worm-eating Warbler
(Helmitheros vermivorus)
Tennessee Warbler
(Vermivora peregrina)
Parula Warbler
(Parula americana)
Black-throated Blue Warbler
(Dendroica caerulescens)
Rose-breasted Grosbeak
(Pheucticus ludovicianus)
Dickeissel
(Spiza americana)
Evening Grosbeak
(Hesperiphona vesperfrina)
Purple Finch
(Carpodacus purpureus)
Cassin's Finch
{Carpodacus cassin11)
Lawrence's Goldfinch
(Spinus lawrencei)
23
-------
Hooded Warbler Red Crossbill
(VMlsonia citrina) (Loxia curvirostra)
Painted Redstart Rufous-crowned Sparrow
(Setophaga picta) (AimophUa ruficeps)
Orchard Oriole Cassin's Sparrow
(Icterus spun'us) (Aimophila cassinii)
Rusty Blackbird Clay-colored Sparrow
(Euphagus carolinus) (Spizella pallida)
Hepatic Tanager Black-chinned Sparrow
(Piranga flava) (Spizella atrogularis)
Cardinal Chestnut-collared longspur
(Richmondena cardinal is) (Calcarius ornatus)
BIRDS OF LAS VEGAS WASH
The following list of birds for the Las Vegas Wash and Las Vegas Bay was complied
by Mr. Charles S. Lawson. Mr. Lawson has been identifying birds for 27 years
and is currently submitting manuscripts of birds, new or unusual, to Nevada, to
Condor and collaborating with Fred Ryser, Ph.D., Department of Biology, University
of Nevada, Reno in the preparation of a manuscript for a book on the birds of
Nevada. Mr. Lawson's full report is unpublished at this time and can be found
in the Las Vegas Valley Water District Library and the Clark County Library.
This list words 251 species that can be found using Las Vegas Wash and Las Vegas
Bay. This represents 65% of the species known to have cccured in Nevada. To
date, 346 species of birds have been seen in the regional area. 72% of the birds
found in Southern Nevada are found in the Las Vegas Wash-Bay area. There are five
birds on this list which appear on the rare and endangered species list; Golden
Eagle, Prairie Falcon, and Peregrine Falcon. Many of the birds found on Mr. Lawson's
list are also found in other areas of the regional environment.
24
-------
BIRDS OF LAS VEGAS WASH AND LAS VEGAS BAY
Definitions of Symbols Used in Table
Species - Nomemclature, both common and scientific, follow the American
Ornithologists' Union Check-list of North American Birds (1957). *ind1cates
a rare or endangered species. See the Rare and Endangered Species 11st.
Column A - Relative Abundance - The symbols used to indicate abundance
follow Alden (1969). Those symbols are:
A Abundantly encountered Seen on 75-100% of the trips there
C Commonly encountered Seen on 50-75% of the trips there
0 Occasionally encountered Seen on 25-50% of the trips there
R Rarely encountered Seen on 1-25% of the trips there
X Accidental A unique sighting, needs further explanation
These symbols of abundance refer only to the normal seasonal occurrence.
Column B - Seasonal Distribution - These symbols refer to the normal season
of occurrence for each species. Symbols used are:
PR - Permanent Resident
SR - Summer Resident
MR - Winter Resident
TV - Transient Visitor - 1s migrant through the area both spring and fall
Ace - Of accidental occurrence in this area
Column C - Breeding species - Indicated by an x
Column D - Found 1n Las Vegas Wash - indicated by an x
Column E - Found 1n Las Vegas Bay, Lake Mead - indicated by an x
Column F - Species most affected by loss of water - indicated by an x
Column 6 - Species least affected by loss of water - Indicated by an x
(Columns F and G indicate a personal opinion of the author, based on
twenty-seven years field experience)
Column H - Rare and/or endangered species - indicated by an x
25
-------
Species List with Data for Each
Species
A
B C D E F G H
Common Loon
(Gavia irmer)
Red-throated Loon
(Gavia stellata)
Horned Grebe
(Podiceps auritus)
Eared Grebe
(Podiceps caspicus)
Western Grebe
(Aechmophorus occidental is)
Pied-billed Grebe
(Podilymbus podiceps)
White Pelican
(Pelecanus erythrorhynchos)
Brown Pelican *
(Pelecanus occidental is)
Blue-booted Bobby
(Sula nebouxii)
Double-crested Cormorant
(Phalacrocorax auritus)
Great Blue Heron
(Ardea herodias)
Green Heron
(Butorides virescens)
Little Blue Heron
(Florida caerulea)
Common Egret
(Casmerodius albus)
Snowy Egret
(Leucophoyx thula)
Black-crowned Night Heron
(Nycticorax nycticorax)
American Bittern
(Botaurus lentiginosus)
Wood Ibis
(Mycteria americana.)
White-faced Ibis
(Plegadis chihi)
0 TV, WR
R WR
0 TV, WR
A TV, WR
A TV, WR
x x
x x
xx x
xx x
xx x
C PR x x x x
R TV xx x
X Ace x xx
X Ace x xx
A PR xx x
C PR xx x
0 TV, SR xxx
X Ace x x
0 TV x x
0 TV xx
0 PR xx
0 TV xx
X Ace xx
C TV xxx
26
-------
Whistling Swan R TV, WR x x x
(Olor columbianus)
Canada Goose 0 TV, WR x x x
(Branta canadensis)
Snow Goose R TV, WR x x
(Chen hyperborea)
Mallard C TV, WR xxx
(Anas platyrhynchos)
Gadwall 0 TV, WR xxx
(Anas strepera)
Pintail A TV, WR xxx
(Anas acuta)
Green-winged Teal A TV, WR xxx
(Anas carolinensis)
Blue-winged Teal 0 TV, SR x x
(Anas discors)
Cinnamon Teal A PR x x x x
(Anas cyanpptera)
American Widgeon 0 TV, WR xxx
(Mareca americana)
Shoveler C TV, WR xxx
(Spatula clypeata)
Wood Duck R WR x x
(Aix sponsa)
Redhead C TV, WR x x x
(Aythya americana)
Ring-necked Duck. R TV, WR x x x
(Aythya collaris)
Canvasback 0 TV, WR x x x
(Aythya valisineria)
Greater Scaup R WR x x
(Aythya marila)
Lesser Scaup C TV, WR x x x
(Aythya affinis)
Common Goldeneye 0 TV, WR x x x
(Bucephala clangula)
Bufflehead C TV, WR x x x
(Bucephala albeola)
White-winged Scoter X Ace x x x
(Melanitta deglandi)
Ruddy Duck A PR x x x x
(Oxyura jamaicensis)
-------
Hooded Merganser R TV x x x
(Lophodytes cucullatus)
Common Merganser C WR x x x
(Mergus merganser)
Red-breasted Merganser A WR x x x
(Mergus serrator)
Turkey Vulture 0 TV x *
(Cathartes aura)
Goshawk R TV x x
(Accipiter gentilis)
Sharp-shinned Hawk 0 TV, WR x x x
(Accipiter striatus)
Cooper's Hawk 0 TV, WR x x x
(Accipiter cooperii)
Red-tailed Hawk C PR x x x
(Buteo jamaicensis)
Red-shouldered Hawk . X Ace x x
(Buteo lineatus)
Swainson's Hawk C TV x x
(Buteo swainsoni)
Rough-legged Hawk R WR x x
(Buteo lagopus)
ferruginous HawK* K WK x x
(Buteo regal is)
Golden Eagle R WR x x x
(Aquila chrysaetos)
Marsh Hawk C WR x x
(Circus cyaneus)
Osprey * 0 TV x x x x
(Pandion haliaetus)
Prairie Falcon* 0 WR x x x
(Falco mexicanus)
Peregrine Falcon* R WR x x x x
(Falco peregririus)
Sparrow Hawk A PR x x x
(Falco sparverius)
GambeTs Quail A PR x x x x
(Lophortyx gambelii)
Virginia Rail A WR x *
(Rallus limicola)
Sora A WR x x
(Pofzana Carolina)
28
-------
Common Galli'nule
(Gallinula choropus)
American Coot
(Fulica americana)
Semi-pal mated Plover
(Charadrius semipalmatus)
Snowy Plover
(Charadrius alexandrinus)
Kill deer
(Charadrius vociferus)
Mountain Plover*
(Eupoda montana)
American Golden Plover
(Pluvialis dotninica)
Black-bellied Plover
(Squatarola squatarola)
Common Snipe
(Capella gallinago)
Long-billed Curlew
(Numenius americanus)
Whimbrel
(Numenius phaeopus)
Upland Plover
(Bartramia longicauda)
Spotted Sandpiper
(Actitis macularia)
Solitary Sandpiper
(Tringa solitaria)
Millet
(Catoptrophorus semi palmatus)
Greater Yellowlegs
(Totanus melanoleucus)
Lesser YeTlowlegs
(Totanus flavlpes)
Knot
(Calidris canutus)
Pectoral Sandpiper
(Erolia bairdii)
Least Sandpiper
(Erolia nrinutilla)
Dunlin
(Erolia alpina)
A PR x x x
A PR x x x x
0 TV xx
0 TV xx
A PR x x x x
X Ace x x
X Ace x x
0 TV xxx
C TV, WR xxx
0 TV xxx
X Ace x x
X Ace x x
C TV, SR xx x
R TV
C TV, WR
C TV
X Ace
0 TV, WR
C TV, WR
0 TV
xxx
X X
X X
X X
X X
X X
X X
29
-------
Short-billed Dowitcher 0 TV x x
(Limnodromus griseus)
Long-billed Dowitcher A TV x x
(Limnodromus scolopaceus)
Stilt Sandpiper X Ace x x
(Micropalama himantopus)
Semi-palmated Sandpiper x Ace x x
(Ereunetes pusillus)
Western Sandpiper C TV x x
(Ereunetes mauri)
Marbled Godwit 0 TV x x x
(Limosa fedoa)
American Avocet /\ jy x x x
(Recurvirostra americana)
Black-necked Stilt C TV, SR x x x
(Himantopus mexicanus)
Red Phalarope X Ace x x
(Phalaropus fulicarius)
Wilson's Phalarope C TV x x x
(Steganopus tricolor)
Northern Phalarope 0 TV x x x
(Lobipes lobatus)
Glaucous-winged Gull x Ace x x
(Larus glaucescens)
Herring Gull C WR x x x
(Larus argentatus)
California Gull A WR x x x
(Larus californicus)
Ring-billed Gull A WR x x x
(Larus delawarensis)
Mew Gull x Ace x x
(Larus canus)
Franklin's Gull 0 TV x x
(Larus pipixcan)
Bonaparte's Gull R TV x x x
(Larus Philadelphia)
Forster's Tern 0 TV x x x
(Sterna forsteri)
Common Tern R TV x x x
(Sterna hirundo)
Least Tern X Ace x x
(Sterna albifrons)
30
-------
Caspian Tern 0 TV x . x x
(Hydroprogne caspia)
Black Tern 0 TV x x x
(Chlidonias niger)
White-winged Dove R SR x x
(Zenaida asiatica)
Mourning Dove A TV, SR x x x A
(Zenaidura macroura)
Ground Dove x Acc x x
(Columbigallina passerina)
Roadrunner A PR x x x x
(Geococcyx californianus)
Barn Owl R TV x x
(Tyto alba)
Great Horned Owl R PR x x
(Bubo virginianus)
Burrowing Owl u KK x x *
(Speotyto cunicularia)
Long-eared Owl X Acc x
(Asio otus)
Short-eared Owl X Acc x x
(Asio flammeus)
Poor-will X Acc x x
(Phalaenoptilus nuttallii)
Contnon Nighthawk C TV x x
(Chordeiles minor)
Lesser Nighthawk C TV, SR x x x
(Chordeiles acutipennis)
Vaux's Swift 0 iv
(Chaetura vauxii) R
White-throated Swift C TV, bR x x x
(Aeronautes sexatalis)
Black-chinned Hummingbird x IV * *
(Archilochus alexandri)
Costa's Hummingbird R 1V x x
(Calypte costae) .- R TV
Broad-tailed Hummingbird R IV x
(Selasphorus platycercus)
Rufous Hummingbird K IV x x
(Selasphorus rufus)
Belted Kingfisher 0 TV, WR x x x
(Megaceryle lalcyon)
x
31
-------
Red-shafter Flicker A WR x
(Colaptes cafer)
Lewis Woodpecker R TV x
(Asyndesmus lewis)
Yellow-bellied Sapsucker 0 WR x
(Sphyrapicus varius)
Ladder-backed Woodpecker o TV, WR x
(Dendrocopos scalaris)
Eastern Kingbird x Ace x x
(Tyrannus tyrannus)
Western Kingbird A bK x x x
(Tyrannus vertical is)
Cassin's Kingbird 0 TV x x
(Tyrannus vociferans)
Scissor-tailed Flycatcher x Ace x x
(Muscivora forficata)
Ash-throated Flycatcher c SR x x x
(Ifyiarchus cinerascens)
Black Phoebe C PR x x
(Sayornis nigricans)
Say's Phoebe C PR x x x x
(Sayornis saya)
fraill's Flycatcher A TV x x x
(Empidonaz traillii)
Dusky Flycatcher 0 TV x x
(Empidonax oberhol sen)
Gray Flycatcher A TV x x
(Empiodnax wrightii)
Western Flycatcher C TV x x
(Empidonax difficilis)
Western Wood Pewee 0 TV x x
(Contopus sordidulus)
Olive-sided Flycatcher 0 TV x x
(Nuttallornis boreal is)
Vermilion Flycatcher 0 SR x x
(Pyrocephalus rubinus)
Horned Lark A PR x x x
(Eremophila alpestris)
Violet-green Swallow A TV x x x
(Tachycineta thalassina)
Tree Swallow A TV x x x
(Iridoprocne bicolor)
32
-------
Bank Swallow A TV x x
(Riparia riparia)
Rough-winged Swallow A TV x x x
(Stelgidopteryx ruficollis)
Barn Swallow A TV x x x
(Hirundo rustica)
Cliff Swallow A SR x x x x
(Petrochelidon pyrrhonota)
Purple Martin X Ace x x
(Progne subis)
Scrub Jay X Ace x x
(Aphelocoma coerulescens)
Common Raven A PR x x x
(Corvus corax)
Common Crow 0 TV, WR x x x
(Corvus brachyrhynchos)
Pinon Jay R TV x *
(Gymnorhinus cyanocephala)
Verdin A PR x x x x
(Auriparus flaviceps)
Common Bushtit C WK x x
(Psaltriparus minimus)
White-breasted Nuthatch R TV x x
(Sitta carolinensis)
Red-breasted Nuthatch R TV x x
(Sitta canadensis)
Brown Creeper R TV x x
(Certhia fanvilaris)
House Wren C WR x x
(Troglodytes aedon)
Winter Wren R WR x x
(Troglodytes Troglodytes)
Bewick's Wren C PR x x
(Thryomanes bewickii)
Cactus Wren C PR x x
(Campylorhynchus brunneicapillum)
Long-billed Marsh Wren A PR x x x x
(Telematodytes palustris)
Rock Wren C PR x x x
(Salpinctes obsoletus)
Mockingbird C PR x X
(Mimus polyglottos)
33
-------
LeConte's Thrasher 0 PR x x
(Toxostoma lecontei)
Crissal Thrasher A PR x x x
(Toxostoma dorsale)
Sage Thrasher 0 TV x x
(Oreoscoptes montanus)
Robin A TV, WR x x x
(Turdue nrigratorius)
Hermit Thrush 0 TV x x
(Hylocichla guttata)
Swainson's Thrush 0 TV x x
(Hylocichla ustulata)
Western Bluebird C WR x x
(Sialia mexicana)
Mountain Bluebird C WR x x
(Sialia currucoides)
Townsend's Solitaire 0 WR x x
(Myadestes townsendi)
Blue-gray Gnatcatcher C PR x x
(Polioptila caerulea)
Black-tailed Gnatchatcher o PR x x
(Polioptila melanura)
Golden-crowned Kinglet X Ace x x
(Regulus satrapa)
Ruby-crowned Kinglet A TV, WR x x x
(Regulus calendula)
Water Pipit A TV, WR x x. x
(Anthus spinoletta)
Bohemian Waxwing X Ace x x
(Bombycilla garrula)
Cedar Waxwing 0 WR x x
(Bombycilla cedrorum)
Phainopepla 0 PR x x
(Phainopepla nitens)
Northern Shrike X Ace x x
(Lanius excubitor)
Loggerhead Shrike C PR x x x
(Lanius ludovidanus)
Starling A PR x x x
(Stumus vulgar!s)
Mutton's V1reo 0 TV x x
(V1reo huttoni)
-------
Bell's Vireo 0 SR x x x
(Vireo bellii)
Solitary Vireo 0 TV x x x
(Vireo solitarius)
Red-eyed Vireo R SR x x
(Vireo olivaceus)
Warbling Vireo C TV x x x
(Vireo gilvus)
Orange-growned Warbler C TV, WR x x x
(Vermivora celata)
Nashville Warbler 0 TV x x
(Vermivora ruficapilla)
Virignia's Warbler o TV x x
(Vermivora virgim'ae)
Lucy's Warbler 0 TV, SR x x
(Vermivora luciae)
Yellow Warbler C TV x x x
(Dendroica petechia)
Myrtle Warbler 0 TV x x
(Dendroica coronata)
Audubon's Warbler A TV, WR x x x
(Dendroica auduboni)
Black-throated Gray Warbler 0 TV x x
(Dendroica nigrescens)
Townsend's Warbler 0 TV x x
(Dendroica townsendi)
MacGillivray's Warbler 0 TV x x
(Oporornis tolmiei)
Yellowthroat A SR x x x x
(Geothlypis trichas)
Yellow-breasted Chat C SR x x x
(Icteria virens)
Wilson's Warbler A TV x x x
(Wilsonia pusilla)
American Redstart 0 TV x x
(Setophaga ruticilla)
House Sparrow A PR x x x
(Passer domesticus)
Bobolink x Acc x x
(Dolichonyx oryzicorus)
Western Meadowlark A PK x x x
(Sturnella neglecta)
35
-------
Yellow-headed Blackbird C SR
(Xanthocephalus xanthocephalus)
Red-winged Blackbird A PR
(Agelaius phoeniceus)
Hooded Oriole 0 SR
(Icterus cucullatjs)
Scott's Oriole 0 TV
(Icterus parisorum)
Bullock's Oriole C SR
(Icterus bullockii)
Brewer's Blackbird A TV, WR
(Euphagus cyanocephalu^)
Boat-tailed Crackle R SR
(Cassidix mexicanus)
Brown-headed Cowbird A PR
(Molothrus ater)
Western Tanager c TV
(Piranga ludoviciana)
Summer Tanager R SR
(Piranga rubra)
Black-headed Grosbeak o TV
(Pheucticus melanocephalus)
Blue Grosbeak A SR
(Guiraca caerulea)
Lazuli Bunting 0 TV
(Passerina amoena)
Indigo Bunting R SR
(Passerina cyanea)
House Finch C PR
(Carpodacus mexicanus)
Pine Siskin 0 WR
(Spinus pinus)
American Goldfinch 0 TV, WR
(Spinus tristis)
Lesser Goldfinch C PR
(Spinus psaltria)
Green-tailed Towhee C TV
(Chlorura chlorura)
Rufous-sided Towhee 0 TV, WR
(Pipilo erythrophthalmus)
Abert's Towhee A PR
(Pipilo aberti)
36
-------
Lark Bunting X Ace x x
(Calamospiza melanocorys)
Savannah Sparrow A TV, WR
(Passerculus sandwichensis)
Grasshopper Sparrow X Ace x x
(Ammodramus savannarum)
Vesper Sparrow 0 WR x x
(Pooecetes gramineus)
Lark Sparrow C TV x x
(Chondestes grammacus)
Black-throated Sparrow C TV x x
(Amphispiza bilineata) y
Sage Sparrow A WR x x
(Amphispiza belli)
Slate-colored Junco o WK x A
(Junco hyemalis)
Oregon Junco u WK x *
(Junco oreganus)
Gray-headed Junco 0 WR x x
(Junco caniceps)
Tree Sparrow K WK x *
(Spizella arborea) „,,,,,«
Chipping Sparrow C TV, WR x x
(Spizella passerine) .
Brewer's Sparrow Civ x A
(Spizella breweri)
Harris1 Sparrow . R WR x x
(Zonotrichia querula) »«,,,,»
White-crowned Sparrow A TV, WR x x x
(Zonotrichia leucophrys)
Golden-crowned Sparrow R WR x x x
(Zontrichia atricapilla)
White-throated Sparrow X WR x x
(Zonotrichia albicollis)
Fox Sparrow 0 WR x x
(Passerella iliaca)
Lincoln's Sparrow C WR x x x
(Melospiza lincolnii)
Swamp Sparrow X Ace x x
(Melospiza georgiana)
Song Sparrow A HK x x x A
Lapland Longspur X WR x x
(Calcarius Tapponicus)
37
-------
The following species of fish are presently found in Las Vegas Bay:
*Largemouth black bass
*Channel catfish
*Black crappie
Carp
*Bluegill sunfish
*Rainbow trout
Green sunfish
+Humpback sucker
Western golden shiner
German brown trout
Black bullhead
-Htonytail chub
Mosquito fish
•••Colorado River Squaw fi
*Cutthroat trout
*Silver salmon
*Striped bass
Threadfin shad
Waileye
(Micropteriis salmoides) Abundant
(Ictalurus punctatus) Abundant
(Pomoxis nigromaculatus) Abundant
(Cyprimus carpio) Abundant
(Lepomis macrochirus) Common
(Salmo gairdneri) Common
(Lepomis cyanellus) Common
(Xyrauchen texanus) Common
(Notemigonus crypolencas) Common
(Salmo trutto) Rare
(Ictalurus melas) Rare
(Gila robusta) Rare
(Gambrusia affinis) Rare
sh (Ptychocheilus lucius) Rare
(Salmo clarkii) Common
(Oncorhynchus kisutheh) Common
(Morone saxatilis) Common
(Dorosoma petenense) Abundant
(Stizostedion vitreum) Rare
38
-------
Biota
Basic Biota of the Site Environments
Scientific Name
*
0
0>
HO
t,
5 «
o
Q)
I
"o
0
"o
u
0)
!
Was
CO
o
CO
-3
w
55
§
r-t
0,
c
o
0} to CO
8, 5 2
CO «J £•
CO
•H
Q
(0 Q W
f-t (-) ^ £
•P o -S
CO
•o
(U
IH
« ^
ID CO
Flora
Creosote Bush Community
Creosote bush
Mormon tea
Ratney
Niggerheads
Cholla
Prickley pear cactus
Mojave yucca
Burro bush
Desert Riparian Community
Desert wash willow
Indigo bush
Cat claw
Snakeweed
Salt cedar
Cheese weed
Bassia
Quail brush
Saltbush Community
Shadscale
Hop sage
Agricultural Crops
Larrea divaricata
Ephedra torreyanna
Krameria parvifolia
Echinocactus polycephalus
Qpuntia begelovu ~~~
O. erinacea
Yucca schidigera
Franseria dumosa
Chilopis linearis
Dalea tremonti"'
Acacia greggii
Gutierrezia'sarothrae
Tamarix gallica
Hymenoclea salsola
Bassia nyssopiioITa'
Atrip lex lentiformis
Atriplex confertifolia
Grayia spinosa
X
X X
X X
X X
X X
X X
X X
X
X X
X
X
X
X
39
-------
•K-
CO
CO
13
CQ
- 1
C3 3
*j 'H
42 Q
OH co
HtUE)
^ "O
^ 3
-------
a
0)
Common Name
Abert's towhee
House finch
Red-tailed hawk
Verdin
Mourning dove
Starling
Song sparrow
Brown-headed cowbird
Mockingbird
Bewick's wren
Reptiles
Side -blotched lizard
Western whiptail
Zebra-tailed lizard
Desert Iguana
Leopard lizard
Pacific gopher snake
Coachwhip
Sidewinder
Scientific Name
Pipilo aberti
Carpodacus mexicanus
Buteo jamaicensis
Auriparus flaviceps
Zenaidura macroura
Isturnus vulgaris
Melospiza melodia
Molothrus ater
Mimus polyglottos
Thryomanes bewickii
Uta stansburiana
Cnemidophorus Tigris
Callisaura draconoides
Dipsosaurus dorsalis
Cnotaphytus wislizeni
Pituophis catenifer
Masticophis nageilum
Crotalus cerastes
« 0
c/5 Z*
rH O
•3 u
^ **
CD
•H
I-H
t-
X
X
X
X
X
X
X
X
*Information as to the exact location of this element is insufficient to determine
existing biota.
41
-------
STATE OF NEVADA
WATER POLLUTION
CONTROL REGULATIONS
ADOPTED BY THE STATE ENVIRONMENTAL OBSESSION
OCTOBER 2k, 1973
DEPARTMENT OF HUMAN RESOURCES
BUREAU OF ENVIRONMENTAL HEALTH
CARSON CITY, NEVADA 89701
-------
WATt.R QUALITY STANDARDS
U« VcgJ> Va«h
Control Point
Horih Shore Hold (Ho sampling will be required upstream of the control
point If the regulation* ire *ati*fle' ' "' J ' »
Sol core -.h3« S
No1 •"• 'kjn u
Kone when vater l»ir*rl''"
li greater than cr t','*^
14':.
1* when water teap*ra'.«re
1*** than or equal to 11*
WUhln r'anje 7.5 - 8.2
Within range 1.0 - 8.5
Dl**olved Oxygen - o
Average (June through Sept either) Not le«« thjn fc.O
Single Value *" »••• th*n S'°
pH Unit*
Annual Median
Single Value.
MD -
Sligle Value.
Not aore tK»n 2
rho«phate«
(Pending further analysis)
Annual Av.r*ge
MF Coltforns/100 "I (Avcricc of the laat five »a»plr»)
Mixldua value of 1000 It Mf Fecal Streptococci are UM than lO.V
Kiximuii value of 500 if MF Fecal Streptococci are !*§» than 20.
To apply to all «wln»lng area* of the Colorado Rtver within Ke»»da.
The "CuWellne* for For».ilailng Water Quality Standards for the lnter»t»!e *3:r
of the Colorado River Sy*lc»" as adopted January 11, 1967. are tncorporatcJ >*
euppU»enl to lh« etandard. for thl* «trea« (Appendix A).
-------
WATER DUALITY STANDARDS
Colorado River
Conceal Point
Cage Section looted half • »11« down* true, fro* Davl* Dm
Temperature *C
Avenge (June through September) Not watt thin 20
SUMCT Single Value . . Not aort thin 23
Winter Single Value Not «ore thin 16
Allowable texperature Increase above
natural receiving vater tnperaturea Not moit thin 1
pi Halt*
Annual Median Within rinfte 7.S - 8.0
Slogl* Valua Within r«ng« 6.S - «.S
Dl«aol*ed Oxygen - •(/!
Average (June through Septe«b«r) . Not letf tHan 6.0
Single Value Not let* than 5.0
•00 - mill
Single falue Not we* than 3
nwtphatt* (f04) - «g/l
(Pending further inalrcla)
Hltratci (NO}) - ag/1 (tentaiive)
Single Value Not aorc than 7.0
Annual Average. Hot aort than i.O
TtM "Coldellnea for Foraulatlng Water Quality Standard* for the loteratate Water!
•( the Colorado Elver Sjritea" a* adopted January U. 196?, are Incorporated •• •
td the ataodarda (or tMa atreaa (Append!* A).
44
-------
AMENDMENTS TO NEVADA'S
WATER POLLUTION CONTROL REGULATIONS
APR 9 1974
I. Amend Article 3.2.2 to read:
The duration of permits may be variable, but shall not exceed
5 years. The expiration date shall be recorded on each permit
issued. A new application must be filed with the Department to
obtain renewal or modification of a permit. Applications for renewal
shall be filed at least 180 days prior to expiration of permit.
11. Amend Article 3.3.2 to read:
Authorized representatives of the Bureau of Environmental
Health shall be permitted access to the premises of all facilities
owned or operated by the permittee at all reasonable times for the
purpose of making inspections, surveys, collecting samples,
obtaining data, and carrying out other necessary functions related
to the permit.
III. Amend Article 3.4.1 by adding the following sentence after the fifth sentence
of Article 3.4.1: "In the case of a municipal, State, or other public
facility the application must be signed by either a principal executive
officer* ranking elected official, or other duly authorized employee."
IV* Add the following section to Article 3:
3.9 Emergency Powers
In accordance with the powers granted in subsections 1, 9 and 12 of
NRS 445.214 and NRS 445.317, 445.321, 445.324, 445.327, 445.331, 445.334
and 33.010, the Director may take any appropriate action authorized under
the Nevada Water Pollution Control Law against a pollution source or
any combination of sources which the Director has evidence is presenting
an imminent and substantial endangerment to the health or welfare of
persons, where such endangerment is to the livelihood of such persons.
V* Amend 4.1.2(d) by adding the following paragraph:
The presence of toxic materials in a water shall be evaluated
by use of a 96-hour bioassay. Survival of test organisms shall not
be less than that in control tests which utilize appropriate experi-
mental water. Experimental water shall be obtained from the most
upstream control point in the stream system, or laboratory water with
quality closely approximating that of the most upstream control point,
or other appropriate experimental water defined by the State and
concurred in by EPA. Failure to determine presence of toxic substances
by this method shall not preclude determination of excessive levels of
toxic substances on the basis of other criteria or methods.
-------
VI. Amend Table 22 (Virgin River) and Table 23 (Beaver Dam Wash) in Article
A.2.5 by adding:
Color
Color shall not exceed' that characteristic of natural conditions by more
than 10 units Platinum Cobalt Scale.
Turbidity
Turbidity shall not exceed that characteristic of natural conditions
by more than 10 Jackson Units.
VII. Amend Table 44 (Lake Tahoe) in Article 4.2.5 by adding:
Turbidity
In order to minimize turbidity levels in the Lake and tributary streams
and control erosion:
1. The discharge of solid or liquid* waste materials including soil,
silt, clay, sand, and other organic and earthen materials to Lake
Tahoe or any tributary thereto, is prohibited.
2. The discharge of solid or liquid waste materials including soil,
silt, clay, sand, and other organic and earthen materials to lands
below the high water rim of Lake Tahoe or along any tributary to
Lake Tahoe in a manner which will cause the discharge of such waste
materials to Lake Tahoe or any tributary thereto, is prohibited.
3. The placement of material below the high water rim of Lake Tahoe
or along any tributaries to Lake Tahoe, in a manner which will
cause the discharge of solid or liquid waste materials including
soil, silt, clay, sand and other organic and earthen materials to
Lake Tahoe or any tributary thereto, is prohibited.
VIII. Amend Table 45 (Willow'Beach Colorado River), in Article 4.2.5 by replacing
the coliform standard and adding color, turbidity and phosphate standards
by adding:
Phosphates (PO,) - mg/1
Color
Annual Average not more than 0.040
Maximum value in 90% of samples... not more than 0.060
Color shall not exceed that characteristic of natural conditions by more
than 10 units Platinum Cobalt Scale.
-------
Turbidity
Turbidity shall not exceed that characteristic of natural conditions by
more than 10 Jackson Units.
Fecal Coliform
The fecal coliform concentration, based on a minimum of 5 samples during
any 30-day period shall not exceed a geometric mean of 200 per 100 milli-
liters, nor shall more than 10% of total samples during any 30-day period
exceed 400 per 100 milliliters.
IX. Amend Table 46 (Colorado River below Davis Dam) in Article 4.2.5 by replacing
the coliform standard and adding color, turbidity and phosphate standards by
adding:
Phosphates (PO^) - rag/1
Annual Average. *. not more than 0.060
Maximum value in 90% of samples. not more than 0.100
Color
Color shall not exceed that characteristic of natural conditions by more
than 10 units Platinum Cobalt Scale.
Turbidity
Turbidity shall not exceed that characteristic of natural conditions by
more than 10 Jackson Units.
Fecal Coliform
The fecal coliform concentration, based on a minimum of 5 samples
during any 30-day period shall not exceed a geometric mean of 200 per
100 milliliters, nor shall more than 10% of total samples during any
30-day period exceed 400 per 100 milliliters.
X. Amend the temperature standard in Table 47 (Las Vegas Wash) in Article 4.2.5
to read:
Temperature - *C
Monthly mean - June 1 to September 30 not more than 27°
October 1 to May 31 not more than 23°
Single value in 90 percent of samples:
June 1 to September 30 not more than 31°
October 1 to May 31 not more than 27°
-------
XI. Amend Article 4.2.5 by adding the following table:
TABLE 48
WATER QUALITY STANDARDS
Pyramid Lake
Control Point - Various Points
Temperature - °C
Permissible temperature increase above
natural receiving water temperature.... .....not more than 2
pH Units
Single value ....6.5 - 9.0
Dissolved Oxygen - mg/1
Single value... not less than 6
Fecal Coliform
The fecal coliform concentration, based on a minimum of 5 samples
during any 30-day period, shall not exceed a geometric mean of 200
per 100 milliliters, nor shall more than 10% of total samples during
any 30-day period exceed 400 per 100 milliliters.
XII. Amend Article 4.2.5 by adding the following table:
TABLE 49
WATER QUALITY STANDARDS
Walker Lake
Control Point - Various points
Temperature - *C
Permissible temperature increase above
natural water temperature. not more than 2
Dissolved Oxygen - mg/1
Single value ...not less than 6.0
Fecal Coliform
The fecal coliform concentration, based on a minimum of five samples
during any 30-day period, shall not exceed a geometric mean of 200 per
100 milliliters, nor shall more than 10% of total samples during any
30-day period exceed 400 per 100 milliliters.
-------
XIII. Add the following as a footnote to the phosphate standard in Tables 45
and 46:
Interpretation of this standard shall not be construed to restrict
the phosphorus passing the North Shore Road control point as defined
In Table 47, i.e., monthly mean of not more than 0.5 mg/1 as P and
single value in 90% of samples of not more than 1.0 mg/1 as P but
not to exceed 400 pounds/day during April through October.
ADOPTION: NOW, THEREFORE, by affirmative vote of the Nevada State Environmental
Commission, these Water Pollution Control Regulations are hereby revised and
compliance therewith ordered.
To become effective , 1974.
Norman Glaser, Chairman
Environmental Commission
49
-------
1.59
1.44
1.60
l.Wr
AMENDMENTS
TO THE
STATE OF NEVADA AIR QUALITY REGULATIONS
Complex source. Any property or facility that has or solicits secondary
ftr tdjuoctive activity which emits or may emit any air contaminant for
titkioll there Is an ambient air quality standard, notwithstanding that
•ueh property or facility may not itself possess the capability of emit-
ting such air contaminants. Complex sources include, but are not limited
to:
a. Shopping centers;
b. Spores complexes;
c. Drive-In theaters;
d. Parking lots and garages;
a. Residential, commercial, industrial or institutional developments;
f. Amusement parks and recreational areas;
g. Highways;
h. Sewer, water, power and gas lines;
and other such property or facilities which will result in increased
air contaminant emissions from motor vehicles.
Registration certificate. A document issued and signed by the Director
certifying adequate empirical data for the single or complex source has
been, received and shall constitute approval of location.
Vehicle trip. A single movement by a motor vehicle which originates or
terminates at the single or complex source.
Contiguous Property. Any property which is in physical contact,
touching, near or adjoining. Public property or public right-of-way
shall not be deemed as a break in any contiguous property.
S
3.1*9
3.2.4
3.2.5
'4.3.2
Registration certificates for single and complex sources and operating
permits for single sources may be issued through an approved local air
pollticioa control program.
Within 5 days after receiving an application for registration, the
Director shall determine what, if any, additional information is needed.
Within 15 days after receiving adequate information the Director shall
make a preliminary determination 'to issue or deny issuance of a regis-
tration certificate. Within 75 days after receiving adequate information,
pursuant to Article 13, the Director shall issue or deny issuance of a
registration certificate.
A registration certificate shall only expire if construction of a new
or modified source, including a complex source, is not commenced within
one year from the date of issuance thereof or construction of the
facility is delayed for one year after, initiated.
A stop order can be issued at any' time before the operating permit is
granted, except that a stop order for a source shall not be issued after
construction or modification has commenced if the construction is in
accordance with the provisions of the registration certificate as sub-
mitted and approved by the Director under Article 13 hereof.
appendix D
-------
13.1 General provisions for the review o£ new sourccn.
13.1.1 Prior to the issuance of any registration certificates in accor lain .-
with this Article the applicant shall submit to the Director an environ
mental evaluation and any other information the Director may deem
to make an Independent air quality impact assessment.
13.1.2 Th« preliminary intent to issue or deny issuance of a registration
certificate for a complex source shall be made within 15 days after
receiving adequate information for reviewing the registration applica-
tion. The application, the Director's review and preliminary intent
to Issue or deny shall be made public and maintained on file with the
Director during normal business hours at 201 South Fall Street, Carson
City, Nevada and in the Air Quality Region where the source is located,
at a site specified in a public announcement by the Director for thirty
(30) days to enable public participation and comment. All comments
on the Director's review and preliminary intent for issuance or denial
8ha 11 be submitted in writing to the Director within 30 days after the
public announcement. Within the time period prescribed by Article 3.2.4,
the Director shall make his decision, taking into account written public
comments on the Director's review and preliminary intent for issuing or
denial, project proponent submittal and the effect of such a facility on
the maintenance of the ambient air quality standards as contained tn
Article 12 and the control strategy contained in the Air Quality Implem-
entation Plan.
13.1.3 The Director shall not issue a registration certificate for any source
if the environmental evaluation submitted by the applicant, or if the
Director determines, in accordance with the provisions of this Article,
that the source will prevent the attainment and maintenance of the State
Ambient Air Quality Standards or will cause a violation of the applicable
control strategy contained in the approved Air Quality Implementation
Plan.
13.1.4 The Director may impose any reasonable conditions on his approval,
Including conditions requiring the source owner or operator to conduct
ambient air quality monitoring at the facility site for a reasonable
period prior to commencement of construction or modification, and for
any specified period after the source has commenced operation.
U^.5 Where a proposed source located on contiguous property
is constructed or modified in increments which individually are not
subject to review as provided in this Article, all such increments
occurring since the effective date of this Article shall be added
together for determining the applicability of this Article.
13.1. 6 Approval and issuance of a registration certificate to any
source construction or modification shall not affect the responsibili-
ties of the owner or owners to comply with any other portion of the
control strategy.
13.1.7 Any source or proposed facility shall, upon written application
to the Director, receive within thirty (30) days a written notice of
his determination, either requiring the submittal of an environmental
evaluation or exempting the source from such requirement.
-------
1JL4 Environmental Evaluation
13.4.1 The environmental evaluation required for new or modified slnr.lc <>r
coupler sources, as determined by this Article or as required by
Director, shall Include the following:
13*4*1*1 An environmental evaluation shall be a careful and detailed
int of the environmental aspects of a proposed action.
13.4.1.2 An environmental evaluation shall contain adequate environmental
safeguard^to be implemented by the applicant to provide for the main-
tenance of acceptable air quality and shall consider:
a. Ambient air concentrations before, during and after construction,
empirically calculated with recognized methods as approved by the
Director; or, in the case of existing ambient air concentrations, they
may be measured with approved methods at approved site locations for
not less than one year. Estimates shall be empirically determined for
ambient air concentration immediately contiguous to the facility and
at the point of predicted maximum concentration; within the surrounding
region.
b. Diffusion models used to determine the location and estimated
value of highest air contaminant concentration shall contain:
1. Assumptions and premises.
2. Evaluation-at the recorded most adverse meteorological
conditions in the
-------
AIR POLLUTION CONTROL REGULATIONS-STATE OF NEVADA-SELECTED SECTIONS
SECTION 26. FUEL BURNING EQUIPMENT
2. h. Maximum allowable emission rates of particu-
late matter for heat input greater than 10
million but less than 4000 million BTU per
hour shall be determined by using the equation
Y = 1.02 x "°*231. Maximum allowable emis-
sion rates of participate matter for heat
inputs equal to or greater than 4000 million
BTU per hour shall be determined by using
the equation
Y = 17.0 x -0.568 where Y » allowable rate
of emission in pounds per million BTU and
X = maximum heat input in millions of BTU
per hour.
c. No person shall cause or permit the emission
of sulfur dioxide from any fuel-burning equip-
ment in exce*ss of the quantity set forth in
the following table:
Heat input, millions Maximum allowable rate of
of British thermal emission of sulfur dioxide,
units per hour pounds per hour
1,000 150
5,000 750
10,000 1,500
15,000 2,250
20,000 3,000
25,000 3,750
30,000 4,500
35,000 5,250
40,000 6,000
45,000 6,750
50,000 7,500
d. Maximum allowable emission rate of sulfur
dioxide shall be determined by using the
equation Z = 0.15 X where Z = allowable
rate of sulfur dioxide omission in pounds
per hour and X «= maximum heat input in
millions of BTU per hour.
SECTION 27. PROVISIONS OF REGULATIONS SEVERABI.E
If any provision of these Regulations or the application
thereof to any person or circumstances is held invalid or
unconstitutional, such invalidity or unconstitutionally ^
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SECTION 35.
4. Compliance schedules shall contain as a minimum:
a. Appropriate increments of progress.
b. Final date of compliance with the appropriate
emission limitations.
SECTION 36. AMBIENT AIR QUALITY STANDARDS
1. The following concentrations of air contaminants
shall not he exceeded at any single point in the
ambient air:
a. Sulfur oxides as sulfur dioxide:
Annual arithmetic moan 60 ug/M3 (0.02 ppm)
Maximum 24 hr. concentration 260 ug/M3 (0.1 ppm)
Maximum 3 hr. concent rat ion 1300 ug/M3 (0.5 ppm)
h. Suspended particulatc matter:
Annual geometric mean 60 ug/M3
Maximum 24 hr. concentration 150 ug/M3
c. Carbon monoxide:
Maximum 3 hr. concentration 10 mg/M3 (9.0 ppm)
Maximum I hv. concentration 40 mg/M3 (35.0 ppm)
54
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d. Photochemical oxiclant:
Maximum 1 hr. concentration 160 ug/M3 (0.08 ppm)
c. Non-rnethanc hydrocarbons:
Maximum 1 hr. concentration 160 ug/M3 (0.24 ppm)
f. Nitrogen dioxide:
Annual arithmetic mean 100 ug/M3 (0.05 ppm)
2. ug/M3 means micrograrns of air contaminant per cubic
meter of air.
mg/M3 means milligrams of air contaminant per cubic.
meter of air.
ppm means parts of air contaminant by volume per
million parts of air by volume.
3. The methods of measurement shall be those precribed
in Appendices A through F, inclusive, of § 410 of
Chapter IV, Title 42, Code of Federal Regulation,
published in the Federal Register on April 30, 1971.
These may change from time to time.
4. Adoption of these Ambient Air Quality Standards
shall not be considered in any manner to allow
significant deterioration of existing air quality
in any portion of Clark County.
55
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MOBILE SOURCES 2.63%
OTHER SOURCES 0.66%
OTHER
FUGUTIVE
DUST 18.2%
INDUSTRIAL
PROCESSES
56.7%
POWER
GENERATION
21.8%
Participate Emiisioni
POWER
GENERATION
SO2 Emissions
MOBILE SOURCES 6.72%
INDUSTRIAL PROCESSES
1.31%
OTHER SOURCES 2.82%
1973 PARTICULATE AND SO2
EMISSION PERCENTAGES
FOR CLARK COUNTY
AQCR 013
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MOBILE
SOURCES
97.0%
INDUSTRIAL, PROCESSES
1.79%
POWER GENERATION 1.08%
OTHER SOURCES 0.12%
I
i
•«
M
CO Emissions
1973 CO AND HC
EMISSION PERCENTAGES
FOR CLARK COUNTY
AQCR 013
MOBILE
SOURCES
81.43%
HC Emissions
INDUSTRIAL PROCESSES
16.24%
POWER GENERATION 1.65%
OTHER SOURCES 0.68%
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MOBILE
SOURCES
51.97%
POWER
GENERATION
42.84%
INDUSTRIAL PROCESSES
2.2%
OTHER SOURCES 3.04%
NO* Emissions
1973 NOX EMISSION
PERCENTAGES FOR
CLARK COUNTY
AQCR 013
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H xiptiadde
•,--•• r.;.>v
BSCB1V5D
Q A.M. "0" t3™A-
jUN 121974
WASTEWATcR MANAGEMENT
June 12, 1974
Mr. Toia Wiesner
Chairman, Board of Clark County Commissioners
Clark .County Courthouse
Las Vegas, Nevada 89101
Dear Mr. Wiesner:
Enclosed is my statement on the Facilities Report and Environmental
Assessment being submitted for review and/or approval by the
Commission.
Because 1 have been closely associated for several years with the
folllllon Abatement Program for Lake Mead and serve as Resident
r^f £h* Las Veaas Valley Water District, I am submitting this brie*.
!ntrol«ctorylover letter to avoid any confusion as to the District's
position in this matter.
Naturally, the District has actively participated in ^Sewage and
Waste Water Advisory Committee (SWAC) and supplied technical data
to the consultants preparing the reports now under consideration,
I want to clearly state that the ideas,
are derived from my analysis of the reports
Yours^ sincerely,
Thorne J.[Butler, M. D. .
President J-/Las Vegas Valley Water District
TJB:gcs
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8
STATEMENT FROM THORNE J. BUTLER
on
FACILITIES REPORT AND ENVIRONMENTAL ASSESSMENT
to
THE CLARX COUNTY COMMISSIONERS
Both the amended facilities plan and its attached environmental
assessment are directed to accomplishing two goals.
1. The elimination of pollution of Lake Mead by flows from the Las
Vegas Wash. This objective was established by the 1971 Nevada State
Legislature and has been endorsed as being still valid by both of the
consultants who prepared thase reports. The bulk of the facilities
report is devoted to accomplishing this end.
2. The conservation of the potable water supplies available to the
Las Vegas community. This goal is to be met by the substitution of
properly treated waste waters for potable water.
My comments to the first of these objectives are very limited and brief.
I would like to concentrate my comments on the in-valley irrigation,
desalinization and ground water recharge programs. As a member of the
Board of Directors of the Las Vegas Valley Water District I believe
that this program is of paramount importance to the District's goal of
continuing to supply adequate potable water to this area.
With respect to the pollution abatement phase of the project. Table
VII-3, entitled "Monetary Cost Effectiveness"r needs to be corrected.
In the column "Total Annual Cost", the Alternatives 7 and 10 are not
evenly stated. The reason being that, in Alternative 10 one of the
factors for the determination of net annual cost is based upon the
development of the Allen Power Project which will utilize approximately
37% of the annual average flows through the year 2000. Therefore, to
Alternative 10 should be added the cost of piping and pumping the
AWT water to ths power project. To balance the total costs, to
Alternative 7 must be added the cost of treating the secondary effluent
to make it acceptable as an industrial cooling water. Computing the<:e
additional costs, I calculate for Alternative 7, $467.00 per million
gallons treated and for Alternative 10, $438.00 per million gallons
treated. Alternative 7 may be higher in total costs because included
is the pickup and disposal of the ground water discharges. Naturally,
the net annual cost to the Las Vegas community depends on variable
factors such as the amount of federal participation, revenues derived
from the Allen Power Project and possible other minor revenues from
the sale of AWT water.
In the same sense, Table VIII-4 should be corrected to include power
requirements for pumping water to the Allen Power Project in Alternative
10 and for the AWT process in Alternative 7. When these two
alternatives are balanced in the terms of cost and energy consumption,
both programs are equal.
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I would like to make recommendations on the proposed in-valley
irrigation, desalinization and ground water recharge programs a?;
outlined in Sections 8.4 through 8.6. There is little cloubt that the
accomplishing of an in-valley irrigation system to utilize reclaimed
waters for irrigation as a substitute for pumping large amounts of
high grade ground water is a goal that has both short-term and long-
term benefits to this community. For that reason, I feel strongly that
the in-valley irrigation program, as part of the overall Pollution
Abatement Program, should go ahead with all due speed. With respect
to these programs, I would like to recommend that the in-valley
irrigation phase and desalinization aspects be coupled together, and
furthermore, the ground water recharge program be conducted independ-
ently. The reason for these recommended changes in the program are
outlined below.
One of the major problems involving the use of reclaimed waste water
for agricultural irrigation use is the build-up of salt concentrations
in the superficial soil layers. As indicated in this facilities
report and in the Phase III report, the application of large quantities
of AWT water to the soil for agricultural uses will require periodic
leaching with better grade water to assure continuation of plant growth.
The actual percentage of better grade water necessary to accomplish
this leaching varies from 10% to almost 30% of the total volume of
reclaimed water applied. Therefore, periodically, all of the land area
receiving reclaimed waste water from the AWT process will have to be
permitted to apply high grade water, either from wells, Lake Mead water,
or the product of a desalinization operation.
The second element in this interrelated area is the program to develop
ground water recharge. The objective behind ground water recharge, of
course, is to bank in the groundwater aquifer, properly treated waste
water. Everyone who has been involved over any period of t'ime with
the pollution abatement problem in the Las Vegas area, has been
interested in tha possibilities of recharging the ground water. It is
an accepted fact that a requirement for the quality of recharged water
is that it be of quality equal to, if not better than, the water
existing in the underground aquifer. For that reason, AWT water would
necessarily have to be subject to a desalinization process to bring it
to such a quality. In this proposal, the pilot desalinization plant
product water would have a TDS of 150 rog/L. Since the ground water
currently being pumped from the western areas of the valley has an
average TDS or approximately 250 mg/L, it seems that desalinated water
would be perfectly adequate to accomplish ground water recharge.
Unfortunately, there are many other complicating problems associated
with ground water recharge. The report identifiers them and rightfully
takes the position that a pilot recharge program using well water should
bs undertaken to evaluate the feasibility of such a project. My comment,
with respect to the pilot recharge phase, is that a two-year time plan
may be too short to appropriately evaluate the success of a recharge
program. I believe that many consultants recommend that a time period
of from 5 to 8 years is required to appropriately evaluate the
possibilities of accomplishing ground water recharge.
8
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A:-; previously stated, the purpose for ground water rcchetrge is to bank
water in the ground water Aquifer. Therefore, you have to not only
pump the water down into the aquifer, but later, when you decide to
recover it, you have to pump it back out. Both of these efforts
increase the cost of that recoverable ground water.
Because this plan more carefully coupled the in-valley irrigation program
to desalinization and ground water recharge, I believe that a less
expensive approach would be to utilize the desalinated water within the
in-valley irrigation system. Since there is evidence that all in-valley
irrigated areas receiving AWT water will have to be periodically leached
with a higher grade water, then desalinated water would be ideal for
that purpose. Again, our objective of reducing withdrawals from the
ground water aquifer would be maintained. Whether we add to the ground
water volume by recharge, or we reduce withdrawal by substituting
desalinated water, the net effect is to increase the available ground
water. Furthermore, the desalinated water would be appropriately
utilized at a far less cost than pumping it into the aquifer and pumping
it out at a later date. As the desalinization program increased in
size, producing greater volumes of water per day, it could be mixed with
AWT water to, in a sense, sweeten it for various uses.
I would recommend that the location for a desalinization plant be
adjacent to the AWT plant. The report suggests that a desalinization
plant be located on the property of the Las Vegas Valley Water District.
I believe that the construction of a factory-like building in that area
would meet with substantial citizen objections. Might it not be simpler
to construct it naar the AWT plant being proposed? The product water
could then ba added into the in-valley irrigation pipeline system and
be delivered to appropriate sites to be used either for nixing with AWT
water or for the purposes of leaching. Assuming that the various health
arguments which currently prevent the use of desalinated water for
potable purposes are finally solved to everyone's satisfaction, then
excess desalinated waters (when available) could be directly added into
the main transmission line running near the Clark County Sanitation
District from the Southern Nevada Water Project, Furthermore, the brine
produced by such a desalinization program could be pumped into the export
line which will be part of the Allen Power Project.
V7hile I do not want to totally throw cold water on the concept of ground
water recharge, I think that this report permits one to put it into a
different perspective. Ground water recharge has a large number of
unknown factors associated with it and may require a very long time frame
to properly evaluate its success or failure. But, with a large-scale,
in-valley irrigation system on line, it would be possible to make direct
use of desalinated water without the additional cost of pumping it Jnto
the underground and then pumping it back later. For every gallon that
we can apply to the surface it means that we save and conserve another
gallon in our valuable underground aquifer.
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A final recommendation on saline control is less detailed, but does
apply to the overall project philosophy. Since the saline control
program for the Colorado River is receiving strong federal support, I
believe we will see an active program undertaken within the next five
years. For that portion of the saline program which applies to the
Las Vegas Wash discharges, I recommend the Commission adopt the
position that the saline control program planned by the Bureau of
Reclamation be integrated into the pollution project now being
considered.
I appreciate the opportunity of presenting these comments and
recommendations to the Commission. I would recommend that the
Commission adopt both the facilities report and its environmental
assessment as a course of action to solve the pollution of Lake Mead.
Yours
y
ncerely,
Thorne J. Bu
TJB:gcs
GPO 691-211
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