Salinity Update, July 1982

Salinity Update

U.S. Depanment of the

Interior

Bureau

of Reclamation

A Quarterly

Report

on

the

Colorado

River

Water Quality

Improvement Program

July 1962

Oow11sllea111

view of lower las Vegas Wash, loou1g toward Lake Mead.

Ponds in foreground are fed by ground water seepage.

Las Vegas

Wash Revisited

The first water to flow fro<T, Las Vegas Wash to the Colorado R...,.. in recent history. olher than

infrequent

storm runoff,

began

in the early 1940's when waler was diverted from the river to supply a magnesium

processing complex at He11de1

son,

Nevada Hundreds of acres of 18!hngs ponds were bllh between the complex and the wash to rec:er,e

process

wastewater.

The wastewafer

soon began seeping

into the ground through the nearly 30-foot-<leep bed

of

coarse

sand and grawl underlying the ponds. When the wafer reached the less permeable, fioo-grained material associated wi1h a deep fonnation known as the Muddy

Cleek.

it was deflected towatd Las Vegas Wast

A

recent

review of well and

auger

hole logs

revealed a high percentage of gypsum

in subsurface soils throughout the lower Las Vegas Valley. This ind«:ates that the industnal wastewafer probably not only earned process

waste

salts, it also leached native sahs as it seeped ,nto and through the Wash.

As sewage treatment plant effluent from

Las Vegas inc,eased along wi1h the area·s population, the effluent spread further down the Wash until it reached the Lower Wash in

1955. Ten years later, Reclamation began monitoring the salinity of the effluent A 1971 Reclamation report showed that the major inc, : se in salinity appeared to be in the

same readl apparently receiving

seepage

from the industrial taif,ngs ponds.

Earty proposals for controlling wastewater entenng Lake Mead .., the Wash called for

lined channels or pipelines to convey the effluent back to the river below HC>O\'er Darn or to a dry lake north of the Wash. The plan

for exporting waslewater to the dry lake ,nducled us,ng part of the sewage plant effluent to ma,nta,n a greenbeh in Las Vegas Wash. Wastewater released to the upper wash would

not

be completely consumed by the vegetation, so

a

facility to intercept surplus wastewater reaching the

lower wash

was needed.

In 1973,

Reclamation was asked by the

State's Colorado River Commission and the Clark County Board of Commissioners to initiate studies leading to construction of a Federal salinity control plan for the wash. The next year, Reclamation recommended a

salinity control plan that included the previously proposed facility for inte<c:epMQ wastewater in the lower wash as wel as a

bypass p,pefme to collect most ol the better

quality sewage treatment plant e!fluent and

convey it to the wash below the inceroeption

facilmes. This plan was authorized for conslJUCtion by the Colorado River Basin

Saliroty Control Act of June 24, 1974.

Construction

of an accessroadtoabarrier

dam sl1e m the wash began in 19n-the

same

year the industries began containing

~ wastewater in lined ponds. Within 4

months.

saline groundwater SIOpped flowing

from

a

seep

area located downhill

from the

ta,~

ngs

ponds. The salinity concentration of

the groundwater sampled

near

Las

Vegas Wash a1So dropped. Hydro salinity studies completed in 1978 showed that aside from

1ndustnal wastewater

seepage.

there was

very

1

1111e

saline regional grot.rldwater

ememg

Las

Vegas Wash. These indicators of a dmnishing satt load greatly reduced the cost

e!fectJveness of the

planned facilities.

Consequently, construction

was

deferred in

1978

tn

afbN a

rest,

KfV

nf tt:e

area's

hydrology, geology, and potential need for salirvty control.

E-.en

though the regional saline groundwater inflow was essentially

undelectable, Reclamation needed a better

estwnate

of

future groundwater inflow in

response to

anticipated increased urtian

1mgatJon. Aquifer tests in the

area

between

the upper and lower valley have since determined that

seepage

from the irrigation would be impeded from reaching the wash

by the low transmissivity of the intervening

soils. An analys,s of data collected between

1976 and 1979 affirmed that the regional

groundwater inflow continues

to be

1nsigvficant A water and salt budget for this

same

penod also showed that the salt load

was

increasing in the

same

reach

of

the wash as belote. This increase is pm,arily due to

native salts being leached from the wash alluvil.m by the sewage treatment plant

effluent and small amounts ol wastewater

from Olhe< sources.

After 3 years of study, Reclamation's strategy

for

controlling

Las

Vegas Wash sailroty rv:,w will focus on pnNenting stonn

runoff

and wastewater discharge from

moong

with saline soils as they flow to the

Colorado River.

IMialty, the plan calls for pnM)llling

seepage

from wastewater

ditches by

construction of a bypass pipeline to carry

ono&-through cooling water from the industrial complex to the Wash. Shallow

wells will be used to look for changes in both

groundwater levels and quality before and

after

the pipeline iscomplelecl (scheduled for

19133).

Secondly,

Reclamation can

limrt the

seepage

of sewage treatment plant effluent

by constructing a bypass channel along the

north side of the wash. Environmental stud'ies and definite plan preparation for a low-<:ost bypass channel wiU begin in fiscal

year 19133. If an accord

can

be read'led with local agencies on how to

manage

the wastewater in the wash. the bypass channel

could be completed 111 1985.

(Editor's note: Reclamation will

soon

complete a Las Vegas Wash status

report

that summarizes the past

3years

of study and descnbes a strategy

for

reducing the Unit's

salt load to the Colorado R~ by 79,000 tons

pet ;u&F.)

R

ecla

mation

's

McElmo

Creek

Study

The

McElmo Creel< Salinity Control Unit,

located in southwestern Colorado, is neanng

the end of a feasibility level study to

delermine the best

r:nethod

f0< reducing a po,tion of approximately 115,000 tons of salt from entering the Colorado

Rive<

drainage

system every

year. McElmo

Creek drains an area surrounding

Cortez.

Colorado, and much

of

the yearly flow 1n the Creek is

attnbutable to return flows from irrigation of agncuttural lands.

Hydrologic data

gathered

to

date indicates 1hal salt in the area's soils is picked up by groundwater

movement. One

source of the grot.rldwater has been

identified

as

seepage

from

unlined canals, drtches, and laterals

Wllh111 the Montezuma Valley Irrigation

Company's

(MVIC)

del~

system. Another

identified

source is the

excess

application of

irrigation water on irrigated lands in the

area.

Groundwater picks up salts as it

passes

through the area's soits and increases the

saliroty

of

McElmo Creel<. this groundwa1er surfaces to drain into McElmo Creek.

Plans developed by the Bureau of Reclamation's Durango

ProJects

Office and

Fred Rossow,

a

Btnau Soil Scientist

at

h

Durango Projee1s Oflk:e. Inspects

one

ol h

drop

struc1ures

In the

over~r

old

-zuma

Vl!lley Irrigation

Company

dstrtbution system

the Soil Conservation SeMce call for reducing as much

of

the salts picked up by groundwater movement as poss,ble. By reducing the amount of groundwater 111troduced in the area's soils. especially

those derived from

Mancos

Shale, less

groundwater contain,ng less salt tonnage

would retum to

McElmo

Creek. Reciamabon's prelened plan

calls

for

combining two ma111 canals in the MVIC delivery system

in

to

one

canal and lining sections of MVIC canals which have h,gh

seepage

losses.

The

Sod Conservation

SeMce plan calls for increasing the efficiency of or>-fann application of irrigation

water.

Together. these two plans could

reduce the

amou

nt

ol

satt

entering McElmo Creel< by about 78,000 tons each

year

.

A Reclamation draft feasibility

report

is

to

be finished in the

spring

of 1983and will be

integrated with

an

advance draft

environmental impact statement (EIS).

The

final feasibility report and draft EIS will be finished in winter 19133 and will be followed

by the final environmental impact sta1emenl Plans to write

a

feasabdrty report for the McElmo Creel< Sal,ruty Control Unit could change, somewhat depending upon the

outcome

of recent legislation introduced in

Congress which

would authorize the

McElmo Unit, among others, for advanced

planning and construction.

USDA Onfann

S

tudy in M

c

Bmo

Creek

Possible Improvements for Onlarm

JrrigaUon Systems, the draft planning report for the USDA onfann program for saJ1nrty

control,

was

released for inte,ageucy and

pubf,c review in mid-May. The report

discusses six altemative plans for salinity

control. They range from a nonstructural irrigation

water

management program, to a

gravity p,essurized sprinkler imga!Jon

program,

to gravity and pumped pressurized

sprinklers. Additionally, the report includes a

drtch

llring only

attemative.

The

recommended plan incbles the

gravity and pump pressurized sprinklers. It is

estma1ed that 10,300 acres of land will be put

under gravity sprinklers, 8,000

acres

will be

spri~ irrigated using pumped pressure, and 1.!al,ac;res will use lined dilches to

,mpro,,,e

irrigation practice and to better

manage

the water. The installation

cost

is

esbmaled to be $28.000,000; and the polenllal

for

reduction in salt loading is expected to be 43,000 tons per

year

or 3.6

mdl,grams per liter at Imperial

Dam.

The final

report IS scheduled for complebon by

Sep1ember 30,..

t91l2-"

Aquatra

in"

-Joint Venture

The

Department

of the Interior.

w

.

R. Grace &

Co

,

and other ante<ests will work

together to determine the possibility of using

unwarned saline waters from the Upper Colorado River Basin to transport plastic

capsules of coal to the

w~

Coast.

Donald

P. Hodel, Under Sectetary of the

lntenor, said the proposal from W. R. Grace

to explore the feas,bility

of

an aquatrain-a

saline

water

p,peline carrying plastic caps,.*3s

of

dry, clean

coal

- "

appears

to offer significant potential." This proposal

was

further outlined

in the January 1982 issue of

"SaliMy Update."

"If a technology using these concepts

could be

proven

economically sound, it

would help control the damaging salt content

of

the

Colorado

River, benefit the Nation and

the 15 mollO<l users of the Colorado's water,

and put an t>:1wanted product~ine

water- to good use," Hodel said.

Robert N. Broadbent, Comm&s-saoner of Redamation, said, "It's precisely the type of pro,ect-a cooperative program

among

Federal.

Slate, and industrial interests-we

look for." A project office under the Upper Colorado Region has been eslablished in

Denver

to accomplish Interior's

, . , ... H1no COAL ,..,. •••• JOllltf MUllf W.IU A.00(0 COIKEPTUAl SCHEMATIC .-CAPSULE PIPEllNf

l

l

--PV.mc U.G CAl'SUU:S ,rou.., 15Jt lONG

responsibilities. M. J

cr111ton.

Chief of the

Colorado River Water Quality

Office,

has

been named Acting Manager of the Saline

Water Transport and use Office. Suppon

slaff

for the project will be added as

soon

as

poosible.

The Department of the lntenor

oow

has the

au1hority to prepare a plan

of

study, and

pending legislation (Senate Bdl

No

.

2202

and

House am No. H.R. 6097) would enable the

agency

to panicipate in feaslbilrty studies. W.

R.

Grace & Co. will assume the lead role

for deoeloping the innovative coal transport techl IOlogy and formation of a corisortium of private inte<ests for financing the non-Fedefal share. The Colorado River Basin

Salnty

Control Forum. composed of

- t a l i v e s

appoinled by lhe Govemo<s

of

the seven Basin Slates will address "water

nghts ISSUes and olhe< related concepts that

are a matter of slate rather than Federal

junscf,ction.," Hodel said.

The Bureau of Rectamation believes the

project would remove an estimated 250,000

tons

of

salt per

year

from the Colorado River

and help control a major souroe of salt

pollution.

Price

River Basin Research

Report Complete

The Colorado River Water Quality Office

has received the final report of a study dorie

in the

Pnce

River Basin by the

Utah

Water

Reseatch Laboratory. The report is entitled,

"Salt Uptake in Natural

Channels

Traversing

Mancos Shales in the

Pnce Raver

Basin,

Utah.· It is the result

of

field

work dOne from 1975 to 1977 and subsequent analysis. A

Basin Simulation Assessment Model

oo,,

eloped at Utah State University was

applied to the Price Rrver Basin in an attempt

to distnbute the various sources of salt, and these results are presented.

Copies of the

report

are available

from: Colorado River Water Quality Office,

0-ICXX); Bureau of Rectamation; P. O. Box

2!:a11;

Denver.

CO 00225.

Las

Vegas Wash

Planning

Team

Leader

An Tuma joiried lhe Lower Colorado

Reg,on Office..in 1975, initially wor)<ing

oo

plans and designs for the

Southern

Nevada

Water Project and Las Vegas Wash Unit He

moved to the

Southem

Nevada Construction

Office in 1977, then rewmed to the Regional

Office in 1978 to become planning team

leade< for the Las Vegas Wash Unit restudy.

t-is

current position

.

Before coming to the LC Region, Tuma worked in the Bureau's Upper Rio Grande

Protects

Office in Albuquerque, New Mexico.

A 1(}year Redamation employee, Tuma IS a graduate of Louisiana Tech University, and a registered civil eng,rieer ,n Nevada.

Meeker Dome Water Levels

Deel

ease

Monrtoring of the observation wells and

springs in the Meeke< Dome area show

continuing decline in the saline wate< levels in the area. The pluggo,g of Scott. James, and Marland wells

was

oompleted in June 1981 as pan of

verification

activities to ascertain the salt loading mechanism in the

Meeker Dome area. Monitoring will continue

for anothe< two

years

to confirm that the

plugging of the abandoned oil and

gas

wells

has eliminated the salt loading to the White Raver.

6

5

AVAILABLE 4

SOIL

3

.

5"

l

rr

i

gat

i

ons

1

F

i

e

l

d

Capacity!

j_

___

-WATER

(inches)

3

2

1.

5"

Irr

n

s

.

~

W

i

lting

Po

i

nt

Light Frequent lnigations

Beneficiar?

Can

light frequent irrigat,ons minimize salt return

to

the river? Recent

evaluationS

ol

automated

i

rrigatio

n

systems in Colorado and Idaho sh<NI that farmers who hlNe

automated

systems irrigate

more

frequently With less water

per

irrigation. The general

iesuhs

are

Illustrated in the

f,gure.

Soil water

contents, generally do not reach the extreme lows and highs under the

more

frequent

Irrigation

as compared to

COCiiiOI

schedules ol

i

rrigation

.

Mossing the extreme lows helps avoid water stress and crop yield

rerucbOn. Missing the extreme h,ghS avoids

loss ol water by deep percolation. teaching of

nitrates and reduces the retvm

of

sallne

ground

water

to

the river.

Don Craig in Letha. Idaho. and Ricllard

Wilcox ., Loma. Colorado. who installed "cablegation· type automated systems last

year

with the assistance of the Soil

Conservation Service and the Snake River Conservalion Research Center, Agricultural

Research

Sevice. were recently asked why they oow irrigate mo;e lrequent!y with lesS

water per ,mgation. Their

answers

were practically identical, "Because the crops

DAYS

grow better, and w,th

my

automated system.

rt only takes a lew extra m,nutes a week to

,

ncrease

the frequency."

Richard's larrn lies

ovec

saline Mancos shale on the banks of the Colorado River. Analyses ol his irrigation practice and sampling of his soil for

water

content

by

the ColoradO State University.

SCS

.

and ARS

indicate practically no deep percolation ooder his lields during the growing

season

.

Fur1her studies

are

planned by the ARS and

SCS

to

evaluate the

cos:s

and benefits of

lqll. frequent irrigations and to develop

1mgat,00 systems which will allow farmers to optimize the utility of then irngation water and mwumize salt loading of our rivers.

USDA Personnel

M.

E.at1

Hess, long associated With USOA's

Salr,ity Cootrol planning

effort

in Colorado,

has been reassigned as Water Management

Engineer for the

SCS

in Colorad<>. Although

E.at1

has changed assigmlents. he is not totally leaving the Salinity Cootrol Program.

Much ol his knowledge and experience will be put to good

use

assisting

SCS

personnel

With implementing the onlatm salinity control program.

-·--

___

..

_

USDA EIS Supplement Available

The USDA has just completed its Salinity Program Final Environmental Impact Statement (EIS) lor the Lowe< Gunnison Basin Umt, Colorado, and Uintah Bas,n Unit. Utah. This EIS was pn,pared as a supplement

to the USBR-SCS

M3Y

1

9

. 1

977. Fina

l

EIS for

the Colorado Rrver Water Quality Improvement Program.

A broad rang& of structural and nonstructural alternatNeS were considered for reducing the salt load from irrigation The

environmental consequences of these alternatives were studied and analyzed. The

recommended plan for each basin consists of improved management ol irrigation water.

water management devices, ditch lining,

ditch structures, pipelines. land leveling, and other practices.

In the Lower Gunnison Basin Unit for the

selected plan, 3,BOO acres of wedand would

be affected and the salinity concentration ol

the Colorado River

at

Imperial Dam reduoed by

34.9

mg/L The recommended plan has

one of the lowest ratios of wetland habitat

loss per 1.oootonsof saltreducllon,

yet

tends

to

maximize net benefits to the farmers and downstream

users.

The recommended plan in the Uintah Basm Unit could impact 13.005 acres of

wetland

while the salinity concentration would be reduced by 10.3 mg/L.

Selected plantings lor food and cover for wildlife, fenetng to exckJdegrazing, and other

mitigating features such

as

nesting platforms

are

being incocpo,aled ,

mo

long-term

agreements with farmers to enhance food and

cover

for wildlife r i pnme areas.

Co

lo

r

a

d

o

River

Wa

t

er Quality Improvement Pr

o

gra

m S

chedule

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-USDA concluded that

the

recommended

plans presented in the EIS

are

the most

effec1M,

means

of

meeting

national goals to

reduce salinity and

serve

the public interest.

No allematJve

or

co

mbination of

alte

m

atives

wiN afford greater protectJon

of the

overall

enwonmental values while accomplishing

the salintty reduction goal ,n the U.S. and

meeting

the

United

Sla

t

es

commitment to Mexico

For copies

ol the report, please write State

Conservationist, Soil

Conservation

Service, PO Box 17107,

Denver

.

CO

w:!17 Of State

Conservationist, P.O. Box 1 t3f,O. Salt Lake Ctty. UT 84147.

u

,.. •

-For questions concerning projects discussed in this newtetter, please

contact the Publtc Affairs Office in the Region responsible for that project. Bureau of Reclamahon

Upper Colorado Regional Office

P.O Box 11568

Sa

lt

Lake City, Utah 84147

Telephone·

Commercial

Bureau of Reclamation

FTS 588-5403 801-524-5403

Lower Colorado Regional Office P.O. Box 427

Boulder City. Nevada 89005

u .... Telephone: Commercial:

-FTS 598-7420 702-293-8420 For answers to general questions or

items you would hke to see included ,n

SALINITY UPDATE, write to Editor, SALINITY UPDATE, 0-1000 Colorado River Water Quality Office

Bureau of Reclamation

PO Box 25007 Denver Federal Center Denver, Colorado 80225

Telephone: FTS 234-4180 Commercial: 303-234-4180

P~104