Solar Evaporation Ponds at the Salton Sea for Salinity Control

Solar Evaporation Ponds at the Salton Sea for

Salinity Control

Process, Progress, and Opportunities

Agrarian Research and Management

Company

under contract to

Solar Evaporation Ponds offer a salinity control method that

is:

Technically feasible

Economically viable

Environmentally friendly

Existing solar salt ponds in operation for over 100 years

Evaluation of suitable area for siting of solar evaporation ponds at the Salton Sea based on soil seepage, slope, and considerations of land use

Large ponds take in brine and expose it to sunlight and

evaporation

Concentrator

Pond 1Concentrator

Pond 2Concentrator

Pond 3

Solid

Salt

Pond

Water from Salton Sea

Bittern

salts

Water volumeConcentration

The evaporation ponds concentrate salt and evaporate water

until only solid and bittern salts remain

Pumps and gravity move the water

Pilot Demonstration Project at Niland

How Evaporation Ponds can Control Salinity at the Salton Sea

Salton Sea

Inflow to Sea: water + salt

No outflow: salt accumulates

Water + salt removed to evaporation ponds:

Water evaporates

Salt remains on shore

Possible Conceptual Design for Solar

Evaporation Ponds

Salt is stored where it is deposited, and the pond levees are built higher to

accommodate it

Bittern salts may not be solid, but they make up a very small

volume

Bittern ponds

Progress at the Pilot Pond Project

Evaporation rates of brine

Salt formation in the crystallizer

ponds

Collection of brine and salt chemistry data

Evaluation of seepage through berms as well as

floor of ponds

Solar Salt Ponds and Wildlife

Wildlife Refuges in Salt Pond Habitat

San Diego National Wildlife Refuge with

Western Salt

Don Edwards NWF San

Francisco Bay with Cargill Salt

CDF&G Wildlife Refuge Napa, State management alone

shallow saline water for feeding

saline water

produces rich food source

nesting habitat

Berms and islands create safe resting places

Crystallizers are a refuge for resting

Lands affected would be

adjacent to, or close to, the existing Sea

margins

Potential accumulation of contaminants in concentrators

and solid salt deposits

Selenium Pesticides Metal residues Other agricultural chemicals such

as fertilizers

Preliminary indications are that these issues will not prove to be problems

for solar evaporation pond implementation

Advantages and Benefits

Solar ponds most economical Solar salt ponds in use for over 100 years Solar salt ponds can be managed for habitat “Win – Win” situation for salinity control and

habitat Alternatives available to deal with loss of

water in the Sea Economic and environmental benefits to

area

Future of Solar Evaporation Salt Ponds at

the Salton Sea

Salinity problem must be addressed in order to maintain habitat values

Assessment of environmental concerns is in progress

The most viable and beneficial solution available to solve the

salinity problem

Salts produced from a typical brine

CaSo4

NaClMgCl

NaSO4

KCl

Ton NaCl / ac/in

Results from the brine chemistry investigations

Chloride

0510152025

B22B27B39B24B21B35

Sample

Wt

% Series1

Series2

Series3

Series4

BR

Magnesium

0

2

4

6

8

Sample

Wt

%

Series1

Series2

Series3

Series4

Calcium

0

0.02

0.04

0.06

0.08

B22B27B39B24B21B35

Sample

Wt

%

BR

AR

h-P

Sulfate

024681012

B22B27B39B24B21B35

Sample

Wt

%

Series1

Series2

Series3

Series4