PHASE 2 TECHNICAL MEMORANDUM 

EVALUATION OF SALINITY CONTROL 

ALTERNATIVES TECHNICAL MERIT 

for 

 PARADOX VALLEY 

SALINITY CONTROL UNIT 

 by 
P HASE 2 T ECHNICAL M EMORANDUM – E VALUATE T ECHNICAL M ERIT OF A LTERNATIVES 

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April 08 2 of 28 

Table of Contents 

Introduction ...........................................................................................................................3

Alternatives Eliminated From Further Evaluation in Phase 1 .........................................4 

Phase 2 Evaluation Methodology and Summary of Findings .................................................7 

Conceptual Groundwater and Surface Water Interaction .......................................................8 

Alternatives 

Alternatives 1: Enhance Existing Injection System ............................................................122

Alternatives 2: Additional Injection Well ...........................................................................133

Alternative 3: Divert West Paradox Creek .........................................................................144

Alternative 4: Zero-Liquid-Discharge ................................................................................166

Alternative 5: Dewvaporation .............................................................................................199

Alternative 6: Other Innovative Treatments .........................................................................20

Alternative 6A: SAL-PROC ........................................................................................20

Alternative 6B: Vibratory Shear Enhanced Process (VSEP) .......................................20

Alternative 9: Conventional Evaporation Basins ..................................................................22

Alternative 11: Agricultural Land Management ...................................................................24

Alternative 12: Add Liner to West Paradox Creek Wetlands ...............................................25

Alternative 14: Integrated Evaporation Pond and Treatment Approaches ...........................26

Consultation, Coordination and Selection of Phase 3 Alternatives ................................28 

Attachments 

ATTACHEMNT A, DATA
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Introduction 

The Phase 1 Technical Memorandum: Identification of Potential Methods, identified 16 

alternatives, with 4 options as part of Alternative 6, for reducing salt loading to the Dolores 

River. Of the 16 identified alternatives, 10 have been identified for additional evaluation. Two 

of the four options included in Alternative 6 will be evaluated further, with the other two being 

eliminated from further evaluation. This technical memorandum will justify the elimination of 6 

of the identified alternatives, and discuss the technical merits of the remaining 10 alternatives. 

Utilizing the numbering system used in the Phase 1 Technical Memorandum, the following 

alternatives have been eliminated from further consideration: 

• Alternative 6C: Product recovery from brine; 

• Alternative 6D: Burning salt water; 

• Alternative 7: Enhanced leakage pits; 

• Alternative 8: Salt bricks; 

• Alternative 10: Diversion tunnel; 

• Alternative 13: Increase consumptive use by phreatophytes; 

• Alternative 15: Line bed and banks of Dolores River; and 

• Alternative 16: Fresh water cutoff wells. 

The alternatives to be further evaluated in this technical memorandum include: 

• Alternative 1: Enhance existing injection system; 

• Alternative 2: Additional injection well; 

• Alternative 3: Divert West Paradox Creek; 

• Alternative 4: Zero Liquid Discharge; 

• Alternative 5: Dewvaporation; 

• Alternative 6A: SAL-PROC; 

• Alternative 6B: Vibratory Shear Enhanced Process; 

• Alternative 9: Conventional evaporation basins; 

• Alternative 11: Agricultural land management; 

• Alternative 12: Line West Paradox Creek wetlands; and 

• Alternative 14: Integrated evaporation pond and treatment approaches. 

As the technical merits of these alternatives were further evaluated, some very rough cost 

estimates were made. These cost estimates were generated to determine if the cost per ton of salt 

removed was even close to the range of values that was acceptable. Alternatives with very high 

cost per ton of salt removed should be removed from future economic and environmental 

evaluation. Alternatives with cost per ton of salt removed in a reasonable range will be further 

evaluated in the Phases 3 and 4 technical memoranda. 
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Alternatives Eliminated From Further Evaluation in Phase 1 

This section provides justification for eliminating some of the initially identified alternatives 

from further evaluation. While this section will provide a specific reason for eliminating the 

alternative, the Constraints section for each alternative in the Phase 1 Technical Memorandum 

contains more information than is presented here. 

Alternative 6C: Product Recovery From Brine 

Nearly all methods of processing the brine to produce a sellable product require very large 

evaporation ponds to concentrate the brine. Once the brine has been concentrated it requires 

further processing, which is usually very energy intensive. Alternative 9, the conventional 

evaporation basin, would likely be required as a starting point for product recovery from the 

Paradox Brine, with additional capital and operating costs needed to process the concentrated 

brine. Since additional costs would be involved in product recovery the product recovery costs 

will likely exceed the proceeds from the sale of the products. The stand alone evaporation basin 

will most likely be more economically viable since it would require no additional facilities. 

In addition to similar costs for just the evaporation ponds needed for this alternative and 

Alternative 9, the chemical composition of the Paradox brine has less economically recoverable 

products (such as magnesium) than other brine sources that are only marginally viable. Facilities 

currently processing brine also have the benefit of economies of scale. The extraction rate of the 

Paradox Unit is very small relative to the volumes processed by viable commercial operations. 

It is clear that Alternative 9 will be more cost effective than this alternative, given the many 

limitations. Therefore, there is no reason to expend further resources evaluating this alternative. 

Alternative 6D: Burning Salt Water 

Early research into this alternative indicates that more energy would be needed to burn the brine 

than would be necessary for electrolysis. With the knowledge that alternatives such as zero 

liquid discharge, and dewvaporation are more energy efficient than electrolysis, there is no 

benefit in further evaluation of this alternative. 

Alternative 7: Enhanced Leakage Pit 

The geologic conditions necessary to make this alternative possible do not exist in the Paradox 

Valley or adjacent areas. Therefore, no further evaluation can be justified. 

Alternative 8: Salt Bricks 

The vendor of this process (XDOBS.com LLC) is proposing that the Bureau of Reclamation 

fund a test and demonstration project for their proprietary distillation process using Paradox 

Valley brine. The salt generated by the distillation process would then be used to test a variety 
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of salt brick casting processes. While a small amount of testing appears to have occurred on the 

salt bricks, the document only offers a theoretical basis for their distillation process. Actual 

testing of the process does not appear to have occurred. The proposed distillation process 

appears to be similar to the dewvaporation that is being evaluated further in this document. 

With actual use of the dewvaporation process occurring, the evaluation of a similar distillation 

process that has not been tested cannot be justified. 

If salt bricks can be an economically viable use for the salt, XDOBS.com can purchase the salt 

that may be generated by evaporation basins or other tested technology and use it to produce salt 

bricks. The Bureau of Reclamation should not fund a test of this unproven distillation process. 

However, if XDOBS.com is willing to fund their own research and testing, the Bureau of 

Reclamation may consider providing the brine for the testing. When testing results are available 

further evaluation may be justified. 

Alternative 10: Diversion Tunnel 

This alternative would be very expensive and has the potential to simply cause the brine to enter 

the Dolores River in a different location. The diversion tunnel would prevent any brine from 

entering the river in the current brine inflow locations, but the brine would still need to be 

removed somehow or it would rise to the surface and/or flow into the river below the tunnel. To 

prevent these negative results, the brine must continue to be pumped. Therefore, the brine must 

still be treated or disposed of with one of the other proposed methods. 

This alternative would further reduce the salt loading to the river but would not eliminate the 

brine. Since this alternative would be very expensive and does not eliminate the problem it has 

been removed from further consideration. 

 Alternative 13: Increased Consumptive Use by Phreatophytes 

This alternative involves using plants to remove fresh groundwater in the theory that reducing 

the volume of fresh groundwater will reduce the production of brine and thereby reduce the salt 

loading to the river. While phreatophytes may indeed reduce fresh groundwater flow towards 

the river it is likely that the areas that could support phreatophytes, such as willows and 

cottonwoods, are already doing it and planting more phreatophytes would require irrigation. 

Thus eliminating any benefit derived from the water removed by the phreatophytes. 

Alternative 15: Line the Bed and Banks of the Dolores River 

This is the same as Alternative 10, with a different method used to isolate the river from the 

brine. Thus, this alternative has the same problems identified for Alternative 10 and has been 

removed from further consideration. 
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Alternative 16: Fresh Water Cutoff Wells 

The theory behind this alternative is that if the fresh water that becomes the brine is removed, 

then no brine will be created. The first problem with this is the difficulty in identifying where 

the recharge area for the water that becomes the brine is located. The investigation to understand 

the groundwater system would be very expensive and would likely determine that the source of 

the water is a regional aquifer that could not be isolated. If the source water for the brine could 

be removed, there is a possibility that the water would be replaced from another source. For 

example, the water level of the fresh water layer that “floats” on the more dense brine in the 

Paradox Valley may drop down far enough to come in contact with the salt dome, thereby 

becoming brine. Thus, eliminating the freshwater layer but not the brine. Given the very 

complicated groundwater system, the large expense necessary to understand the groundwater 

system, and the very limited potential for success, further investigation of this alternative cannot 

be justified. 
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Phase 2 Evaluation Methodology and Summary of Findings 

This approved “Approach to the Work” for Phase 2 provides that, “the FCE team will evaluate 

each candidate alternative for technical viability.” To accomplish that objective, the remaining 

candidates were configured in a preliminary manner to identify major structural components, 

their operational characteristics and relative cost, and cost effectiveness. 

Volume of Brine to be Managed – The volume of brine pumped from the collection system and 

injected in recent years, (about 100 million gallons per year or 310 acre-feet per year (0.43 cfs) 

containing about 109,000 tons of salt per year), is significantly lower than was originally 

anticipated. However, the current collection well operating regimen is intercepting only about 

two thirds of the salt load. Therefore, any strategy for reconfiguring the facilities would need to 

be able to handle a maximum annual volume of about 420 acre-feet per year (0.58 cfs) of brine, 

and 147,000 tons of salt per year. 

Evaluation Methodology – An effort was made to identify relatively comparable systems and 

their costs, to be able to assess the relative merits of the various alternatives. As to the cost and 

cost-effectiveness of alternatives considered in this report, only those available “ball park” costs 

were assessed and these were “scaled” to the specific configuration of that alternative, without 

attempting to bring them to a uniform cost estimate date or develop “comparable” estimates of 

cost for each alternative. This was done to provide a sense of relative economic merit and make 

recommendations as to whether a specific alternative should be further evaluated in Phase 3 

(Environmental Feasibility). In evaluating the relative economics of specific alternatives, an 

estimate of the useful life of the alternative was made, and a discount rate of 4.875% was used, 

as provided in Reclamation’s Federal Register Notice1

 dated November 16, 2007. Cost estimates 

made as part of this phase are very preliminary and will not be presented until they can be 

refined further in Phase 4. 

This technical memorandum provides justification for eliminating some of the initially identified 

alternatives. Table 1 summarizes the recommendations and technical merit of the various 

alternatives 

 

1 CHANGE IN DISCOUNT RATE FOR WATER RESOURCES PLANNING [Federal Register: November 16, 2007 

(Volume 72, Number 221, Page 64669]
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Table 1 

Summary of Results 

Conceptual Groundwater and Surface Water Interaction 

Alternatives 3, 11, and 12 are predicated on the theory that reducing groundwater recharge in the 

western portion of the Paradox Valley will decrease the volume of brine flowing towards the 

Dolores River. There are a number of observations that support this theory. These observations 

are: 

1. Salt loading to the Dolores River typically decreases during the summer when West 

Paradox Creek is diverted for irrigation. During this period, the wetlands and ponds 

adjacent to the river in the brine inflow area are dry. Many graphs have been prepared 

showing this relationship. One of these figures is included in the attachments (see Figure 

A-1). 

2. During the winter of 2003-2004, a landowner adjacent to the river in the brine inflow 

area constructed some ponds. When the ponds were filled from West Paradox Creek it 

was observed that salt loading to the river increased. It has also been observed that a 

decrease in the salt loading corresponded to the time when the ponds dried up. When 

water was plentiful in 2006 and the ponds didn’t dry up, the salt loading to the river did 

not decrease as in previous years. The memoranda prepared by Andy Nicholas, Facility 

Manager of the Paradox Valley Unit, are included in the attachments. 

3. In general, it appears the annual total salt loading is lower during drought years than it 

is during years with normal, or above normal precipitation (see Table A-1 in the 

Alternative 

No.

Alternative Name Relative 

Technical Merit

Expected Relative 

Cost Effectiveness 

($/Ton)

Recommend for 

Evaluation in Phase 3

1 Enhance Existing Injection System Poor Excellent Yes 

2 Additional Injection Well Good Poor Yes 

3 Divert West Paradox Creek Good Good Yes 

4 Zero-Liquid-Discharge Good Fair Yes 

5 Dewvaporation Unproven Excellent Yes 

6(A) SAL-PROC Unproven Unknown No 

6(B) Vibratory Shear Enhanced 

Process (VSEP) 

Questionable Unknown Yes 

9(A) Conventional Evaporation Basin – 

Radium Site 

Good Poor Yes 

9(B) Conventional Evaporation Basin – 

East Paradox Valley 

Good Excellent Yes 

11 Agricultural Land Management Good Excellent Yes 

12 Add Liner to West Paradox Creek 

Wetlands 

Good Poor No 

14 Integrated Evaporation Pond and 

Treatment Approaches 

Fair Excellent Yes 
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Attachments). The correlation between annual precipitation and annual salt loading is not 

perfect, but there does appear to be a pattern. The fact that the correlation is not perfect 

indicates the complexity of the system, suggesting that other factors, such as the ponds 

mentioned above, impact the salt loading rate. 

4. When the Paradox Valley Unit was being developed in the 1970s over 200,000 

tons/year of salt was estimated to be flowing into the Dolores River. In the last 7 years 

the combination of injected brine and salt loading to the river averages about 147,000 

tons/year. Between these times much of the irrigation in the valley has converted from 

flood to sprinkler irrigation. Pumping of the fresh water layer has also likely increased. 

This observation suggests that improved irrigation efficiency has contributed to the 

reduction in total salt loading. 

Flow records were kept for two sites on West Paradox Creek between 1944 and 1952. The first 

site is the West Paradox Creek near Paradox, which is at the west end of the Valley, before 

irrigation water is diverted. The second site is the West Paradox Creek near Bedrock, which is 

near the confluence with the Dolores River. Charts generated from this data (see Figures A-3 to 

A-9 in the Attachments) indicate that the flow of West Paradox Creek near Paradox is largely 

diverted during spring runoff and the irrigation return flow returns to the creek as drainage 

accretions during the fall and winter. During the 1944-52 period, West Paradox Creek 

contributed approximately 3,100 acre-feet per year to the Dolores River, while approximately 

6,200 acre-feet were diverted for irrigation. Since the valley is underlain by a salt formation, it is 

logical that some portion of the 3,100 acre-feet per year that is not consumptively used is 

contacting the salt dome and contributing to the brine that is surfacing in the river and being 

pumped from the collection wells. 

The patterns of historical Dolores River salt loading and the historical flow of West Paradox 

Creek near Bedrock have a similar shape, as shown in the Figure 1: 
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Figure 1 

Dolores River Average Salt Pickup

Vs. West Paradox Creek nr Bedrock Flow

10,000

12,000

14,000

16,000

18,000

20,000

22,000

24,000

26,000

Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

Month

1971-11 Average Salt 

Pickup (Tons per Month)

0

100

200

300

400

500

600

700

1941- 52 Average Flow 

(Acre-Feet per Month)

Dolores

River

Salt

Pickup

West

Paradox

Creek

near

Bedrock

Data collected between 2000 and 2006 show that an average of 37,000 tons per year of salt and 

4,100 acre-feet per year flowed into the river as it passed through the Paradox Valley. Most of 

the flow entering the Dolores River is relatively fresh runoff, therefore, if the 37,000 tons per 

year was comprised solely of 260,000 mg/l brine, it would be contained in about 110 acre-feet 

per year of brine. 

Between 2000 and 2006 the collection wells withdrew an average of 310 acre-feet and 109,000 

tons per year from the groundwater system. Therefore, a total of 420 acre-feet and 147,000 tons 

per year of salt reached the Dolores River and collection wells combined. From Figure 1 it can 

be assumed that some part of the 3,000 acre-feet per year of West Paradox Creek agricultural 

deep percolation could contact the salt dome. If only 420 acre-feet per year or 14 percent thereof 

reaches the Dolores River and collection wells, 14 percent of any prevented deep percolation 

would directly reduce the Paradox Valley salt load. For example, if the recharge to the aquifer 

beneath West Paradox Valley was reduced by 100 acre-feet this would correspond to a 14 acrefoot reduction in brine volume. Assuming a 260,000 mg/l brine this corresponds to a 4,900 ton 

reduction in salt loading. This estimate is based on data that is over 50 years old and some 

assumptions as to the correlation between salt loading and the flow of West Paradox Creek. Data 

representative of current conditions should be collected to verify conclusions drawn based on 

this theory 

Whether, some of the irrigation infiltration contacts the salt dome (or not) reducing recharge in 

the western Paradox Valley should reduce the flow of brine towards the river. The fresh water 

layer above the brine in the west Paradox Valley provides the gradient (pressure) that creates the 
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flow of brine towards the river. Reducing the recharge will reduce the gradient (pressure) that 

causes the brine to flow towards the river. Therefore, the rate of brine flow towards the river will 

be reduced if recharge is reduced. Additional groundwater data will be needed before any 

quantification of this reduction can be attempted. 

For evaluating the salt load reductions associated with Alternatives 3, 11 and 12, it is assumed 

that 14 percent of reduced deep percolation reduces an equivalent quantity of 260,000 mg/l brine 

inflow to the Dolores River and the collection wells. 

 
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Alternative 1: Enhance Existing Injection System 

In the Phase 1 Technical Memorandum it was proposed that the effectiveness of the existing 

system could be enhanced by concentrating the brine further before injection. Concentrating the 

brine, thereby increasing the amount of salt removed from the river, is technically feasible. 

Alternative 14 discusses the use of a solar gradient pond to concentrate and heat the brine. This 

is one method for concentrating the brine that appears to be feasible. Although concentrating the 

brine is technically feasible there is potential for the well to be damaged if components of the 

brine, such as calcium sulfate, become too concentrated. Calcium sulfate will create a scale in 

the well if concentrations exceed saturation. 

The sodium chloride concentration in the brine is below saturation. Thus, the sodium chloride 

concentration of the brine can be increased and still be below the point at which precipitation 

occurs. However, other salts in the brine such as calcium sulfate may be near saturation in the 

brine. Further concentration of calcium sulfate or other salts may cause precipitation or scaling 

in the well. Adding to the complexity is the changing solubility of the salts with temperature. 

Some salts are more soluble at higher temperatures while solubility decreases for other salts as 

temperature rises. Solubility increases as temperature increases for sodium chloride while 

solubility of calcium sulfate decreases with increasing temperature. The injection formation 

temperature is currently 30 to 50o

 F higher than the temperature of the injected brine. Therefore, 

precipitation or scale may not be a problem on the surface but may clog the injection well as 

temperatures increase in the well. Given the tremendous investment in the existing injection 

well any increase in the brine concentration should be modeled carefully before a higher 

concentration brine is injected. 

The Bureau of Reclamation has made a considerable effort to optimize the existing injection 

system. All other enhancements identified during this evaluation have already been studied 

and/or implemented prior to this study. It is recommended that the current brine disposal system 

continue to be operated. Increasing the concentration will make the operation more effective at 

disposing of salt but there is a significant risk of damaging the injection well. It appears that 

there are better alternatives available that have less risk. 

This alternative will be evaluated in the next phases to provide a baseline for comparison against 

the other alternatives. 
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Alternative 2: Additional Injection Well 

There are two primary technical issues relating to the feasibility of a second injection well on the 

Paradox project: 

 Location 

 Viability of drilling through the salt dome 

The proposed location of the second well is near the north side of the Paradox Valley near a 

former oil exploration well. This location will allow the second injection well to be completed in 

the same formation as the first well but it should not be hydraulically connected to the first 

injection well site due to faulting between the two sites. The challenge associated with this site 

will be drilling through the salt dome. The infrastructure needed to connect a second injection 

well to the existing extraction system will be needed. This will include a crossing of the Dolores 

River since the proposed site is on the west side of the river. The river crossing will be difficult 

since it will undoubtedly encounter brine in the excavation. This brine cannot be pumped into 

the river after sediment treatment, as is normal procedure due to the salt content. The brine will 

need to be disposed of in the current injection well or some other way 

Drilling through the salt dome in order to reach the desired Leadville limestone formation below 

appears to be technically viable. A river crossing where the excavation encounters the brine is 

also technically feasible. However, both will be very expensive. The costs will be identified as 

part of economic feasibility phase of this study. 

This option should be retained for further evaluation. 
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Alternative 3: Divert West Paradox Creek 

As mentioned above the success of this alternative is predicated on the theory that reducing 

groundwater recharge in the western portion of the Paradox Valley will decrease the volume of 

brine flowing towards the Dolores River. When originally conceived, this alternative was to pipe 

or line West Paradox Creek through the wetland areas adjacent to the river in the brine inflow 

area. With the theory that all groundwater recharge in the western Paradox Valley impacts salt 

loading this alternative can be expanded to include the reduction of agricultural recharge in the 

valley. This would include lining or piping the open ditch system and lining or eliminating the 

numerous ponds in the valley. By reducing the agricultural recharge, the brine flowing into the 

river may be reduced dramatically. 

Short Diversion of West Paradox Creek

Flow records indicate that a pipe capacity of 50 cfs will handle all but the major storms. Flow is 

typically on the order of 20 cfs when not being diverted for irrigation. Assuming that the 

pipeline is sized to handle the majority of flows expected on West Paradox Creek a 36-inch 

diameter pipeline at a slope of 2% should be sufficient. The existing channel will still be needed 

to handle the few days when spring runoff exceeds the capacity of the pipeline or when there are 

large thunderstorms. A pipeline through the wetland area would need to be approximately 

3,200-feet long to bypass the areas of high recharge. It is estimated that this pipeline could 

reduce approximately 5,000 tons of salt loading to the river each year. The 5,000 tons of salt 

removed is an estimate based on limited data. Data, such as groundwater levels (fresh and 

brine), flow in West Paradox Creek, and salt loading rates need to be collected on a regular basis 

before a more accurate estimate for salt removal can be made. 

Full Replacement of Existing Irrigation System

This alternative involves piping West Paradox Creek from the existing irrigation diversion, and 

replacement of the current system of open ditches and ponds with a pressurized irrigation 

system. This pressurized irrigation system would allow application rates to be optimized to 

reduce agricultural recharge of the aquifer. To accomplish this, a 6-mile, 30-inch diameter 

pipeline would start at the current irrigation diversion structure and discharge near the bridge 

over the Dolores River. A 30-inch pipe will handle nearly all flows in West Paradox Creek, 

except for a few days during heavy spring runoff and during large thunderstorms. The existing 

channel would still be used for these peak flows. The diversion of West Paradox Creek has the 

potential to generate high pressures at the discharge to the river. This pressure could be used to 

generate power for the other aspects of the project. If the pressure is not used to generate power 

then pressure reducing valves and/or energy dissipation structures will be needed. 

Approximately 8 miles of 6 to 24-inch diameter pipe would be needed to replace the current 

system of ditches and ponds. 

Although presented as part of the full replacement the piping or lining of West Paradox Creek in 

the western portions of the valley does not need to be included. The piping of the current system 
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of ditches and on-farm improvements can likely be justified in the same manner as similar 

salinity control projects throughout the Upper Colorado River Basin. Namely, eliminate losses 

in open canals and ditches to reduce salinity of return flows. Environmental issues have the 

potential to make piping of West Paradox Creek difficult. However, replacing open ditches with 

a pressurized irrigation system should not encounter environmental problems. 

Both the short diversion and full replacement of the existing irrigation system should be retained 

for further evaluation. 
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Alternative 4: Zero-Liquid-Discharge 

Based on the work to date, ZLD remains as a proven technology. There are several industrial 

installations treating brine near the flow and salinity levels of the project. It will probably be 

necessary to only construct a crystallizer since the high salinity levels negate the need for a brine 

concentrator. This will help to keep the construction costs within manageable levels. 

Since there is limited power supplied to the Paradox site, solar energy can be used to offset 

power requirements from the grid. Depending on the concentrating process chosen, the needed 

offset for Paradox is approximately 3 MW (230 gpm system). This is over 3 times the power 

usage by the injection well. 

Electricity can be generated from the sun in several ways. For a small or medium-sized 

application such as Paradox, photovoltaic cells can be used. A solar cell, or photovoltaic cell, is 

a device which converts light into electricity using the photoelectric effect. Photons in the 

sunlight hit the solar panel and are absorbed by semiconducting materials. Electrons are 

knocked loose from their atoms, allowing them to flow through the semiconducting material and 

to produce electricity. An array of solar panels then converts the solar energy into a usable 

amount of direct current electricity. 

Figure 2 below is a graph of incident solar radiation available at Grand Junction, Colorado on a 

monthly basis. As can be seen, solar energy is not always constant. Summer months have more 

sunlight available, and hence, more solar energy available for use. Because solar energy is not 

continuously available (i.e., night time and cloudy days), storage is an important issue. Solar 

energy is most often stored as heat (thermal) or as electrical energy. 
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0

500

1000

1500

2000

2500

3000

January

February

March

April

May

June

July

August

September

October

November

December

Monthly Incident Solar Radiation (Btu/ft2/day)

Figure 2: Average Incident Solar Radiation at Grand Junction, CO 

Thermal storage uses various methods and materials to store solar energy. Solar energy can be 

stored thermochemically with phase change materials. Suitable materials include organics such 

as paraffins and fatty acids or inorganics such as salts, metals, and alloys. A paraffin wax 

thermal storage system consists of a solar hot water loop connected to a paraffin wax tank. 

During the storage cycle, hot water flows through the storage tank and melts the paraffin. Stored 

heat is then extracted from the tank as the wax resolidifies. Eutectic salts can also be used 

effectively because they are non-flammable, nontoxic, low-cost, have high specific heat 

capacities, and can deliver heat at temperatures compatible with conventional power systems. 

Rechargeable batteries can be used to store electricity from a photovoltaic system. This system 

entails a photovoltaic power source connected to a battery bank via a charge controller and 

inverter. Lead acid batteries are the most common type of battery used with photovoltaic 

systems because they are relatively economical and readily available. Lead acid batteries have 

an energy density of about 110-140 kJ/kg and a charge/discharge efficiency of 70-92%. They 

typically cost between $150-200 per kWh. Sizing of lead batteries depends on the amount of 

storage desired. Typically, storage can not be for more than about a month due to the natural 

discharge of the battery. This is a feasible option for Paradox, but solar power would only be 

supplied for approximately 9 months of the year. During winter months, snow may interfere 
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April 08 18 of 28 

with the functioning of the solar panels. Since power can only be stored for about a month, it 

doesn’t appear feasible to store power for usage during all winter months. 

Electrical energy storage in the form of a battery would be needed and could store energy for up 

to a month. Although sunlight is still provided in the worst month of the year, snow may 

interfere with the operation of the solar panels. Therefore, power may only be able to be 

supplied approximately 9 months of the year. Land requirements are about 5 acres/MW so about 

15 acres may be needed. These facilities could potentially be located within the 350 acres 

presently owned by Reclamation. 

This alternative should be retained for further evaluation. 
P HASE 2 T ECHNICAL M EMORANDUM – E VALUATE T ECHNICAL M ERIT OF A LTERNATIVES 

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April 08 19 of 28 

Alternative 5: Dewvaporation 

The dewvaporation system would be designed to manage a brine volume of 420 acre-feet per 

year (382,000 GPD). Assuming that saturation and crystallization would occur with about 27% 

moisture, about 280,000 GPD of liquid would need to be removed from the brine. The 

approximately 147,000 tons/year of salt generated by this alternative would need to be disposed 

of in a licensed landfill. 

Removal of this volume of liquid would require about twenty-two (28), 10,000 GPD 

Dewvaporation Units. 

Based upon a Navajo Generation Station crystallizer proposal submitted to Reclamation in early 

2004, such a system would have the following components: 

• Twenty-eight 10,000GPD Dewvaporation Units; 

• One 9,000 square foot process building; 

• 0.5 acres of Right-of-way; 

• 241 million lbs of process steam/yr.; 

• 533 MWHrs of electricity per year; 

• 0.3 equivalent person years of O&M labor; 

Pilot scale tests of this technology have been very favorable. However, it has not been used at 

the scale and proposed concentrations in this project. Preliminary cost estimates indicate that 

this alternative may have very favorable costs per ton of salt removed. 

This alternative should be retained for further evaluation. 
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April 08 20 of 28 

Alternative 6: Other Innovative Treatments 

This alternative has been divided into two options. These options remove the majority of salt 

and other minerals but still require some method to dispose of brine reject. Thus, 

implementation of any of these options will still require some method of brine disposal. 

However, the volume of brine to be disposed of is far less and may be offset by the production of 

sellable products. 

Alternative 6A: SAL-PROC 

The primary advantage of the SAL-PROC process is that it has the potential to produce a 

commercial product. However, data shown previously indicates that the Paradox brine is mostly 

sodium and chloride rather than recoverable products such as magnesium, potassium or sulfate. 

A recent SAL-PROC project being pursued by Geo-Processors in Australia has resulted in 

several implementation constraints, and will not be completed (Source: SKM, Keith Collett, 

personal communication). 

The SAL-PROC process does not appear to be technically viable for the Paradox project and 

should not be evaluated further. 

Alternative 6B: Vibratory Shear Enhanced Process (VSEP) 

VSEP has primarily been used for the treatment of low-flow, high solids, industrial wastewaters. 

One study, held at Big Bear Valley in California, was conducted specifically to determine design 

and operational data for use in concentrate management. Assessment of the feasibility of VSEP, 

as well as key design parameters for the design of a full-scale facility, was determined. 

Pilot studies show that both reverse osmosis and nanofiltration membranes can be used in the 

VSEP unit. Concentrate volumes can be reduced by up to 85% if a two-stage VSEP process is 

implemented. VSEP recoveries exceeding 85% result in a decreased flux and the need for high 

feed pressures, which are less than optimal operating conditions. Recoveries greater than 85% 

also resulted in an increase in the lifecycle costs of operating the VSEP. Acid and caustic 

cleanings are needed approximately twice a week, a relatively high cleaning frequency relative to 

conventional RO, to maintain flux. The RO membrane showed better performance than the NF 

membrane at a similar flux range. Permeate quality from the RO membrane was excellent, with 

chloride, TSS, TDS, and sulfate values being very small. 

Since VSEP permeate has very good water quality, blending is possible to increase overall 

recovery of the facility. VSEP does significantly reduce concentrate volume. This makes the 

use of either a wetland or evaporation pond more viable because land requirements would be 

much smaller. VSEP has been shown to be a viable alternative for concentrate management. It 
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April 08 21 of 28 

produces very good quality permeate and can reduce concentrate volumes by up to 85%. 

However, a secondary step would still be needed to treat the concentrate. 

VSEP is technically viable and could be included as a component of a multi-project program for 

Paradox. It should be retained for further analysis, with focus on the O&M costs, particularly for 

the high brine concentrations. 
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April 08 22 of 28 

Alternative 9: Conventional Evaporation Basins 

When evaluating this alternative it became apparent that two options were possible for the use of 

a conventional evaporation basin. These two options are discussed below. 

Alternative 9(a): Conventional Evaporation Basin – Radium Site 

The original Radium Dam evaporation basin was to be located 21 miles to the southeast in Dry 

Creek Basin, had a surface area 3,630 acres, and was designed to hold 93,340 acre-feet with 

nearly 26,000 acre-feet allocated for flood control and surcharge capacity. 

The volume of brine pumped from the collection system in recent years, about 100 million 

gallons per year or 310 acre-feet per year (0.43 cfs), is significantly lower than was originally 

anticipated. However, the current collection well operating regimen is intercepting only about 

two thirds of the brine. Therefore, a conventional evaporation pond strategy to replace the 

existing injection well would need to be able to handle a maximum annual volume of about 150 

million gallons per year, or about 420 acre-feet per year (0.6 cfs) of brine. 

The 1997 Supplement to the DPR contained cost estimates for the original, and a downsized 

project. Included in the following table are the cost estimate for the original Radium Site and 

downsized version. The reported costs were escalated to 1994 costs. No effort has been made to 

escalate costs to 2008 since the costs in 1994 dollars exceed the cost of another injection well. 

The projected cost per ton of salt removed will be far above what is acceptable. However, this 

alternative will be carried forward as a comparison for the other alternatives proposed. 

Original 

1979 plan 

(October 1994 $$) 

Downsized 

1979 plan 

(October 1994 $$) 

Description (5 cfs) (1.5cfs) 

Brine well field 3,683,310 13,683,310 

Hydrogen sulfide stripping plant 4,850,127 3,959,214 

Brine pipeline 12,920,320 8,888,606 

Brine pipeline pumping plants 9,565,574 6,410,077 

Radium dam,dike, and evaporation pond 56,054,857 34,776,000 

Transmission lines and substations 1.291,065 2,764,793 

Permanent operating facilities 375,121 370,312 

Operation and maintenance housing 835,607 120,231 

Capitalized movable equipment 2,245,919 2,245,919 

Service facilities 1,732,532 1,732,532 

Depreciation and salvage <3,034,636:> <3,034,636:> 

 

Emergency reserve O&M fund 329,434 256,092 

Wildlife mitigation 1,067,653 496,555 

Subtotal 91,916,883 62,669,005 

Cultural resource program 18,035 18,035 
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April 08 23 of 28 

Alternative 9(b): Conventional Evaporation Basin – East Paradox Valley 

A series of evaporation basins could be formed in East Paradox Valley by excavating the basins 

and using the excavated material to construct surrounding dikes that would range in height from 

25 to 80 feet. The resulting ponds would vary in capacity from 1,670 to 8,900 acre-feet and in 

surface area from 130 to 500 acres. At any one time 420 acres of evaporation surface area would 

need to be in operation to provide for evaporation of the 420 acre-feet per year of collected brine. 

At the current 109,000 tons per year collection rate, assuming nine acre-feet of volume for every 

42,000 tons, about 23 acre-feet per year of accumulated salt would need to be contained in the 

ponds. Over 100 years, the accumulation of solids would be about 2,300 acre-feet. Only two or 

three ponds would need to be constructed over the 100 year project planning period. 

To prevent seepage, the ponds would be lined with impervious material, such as butyl rubber, 

HDPE, PVC, vinyl, or treated clay (derived from local shale formations such as the Mancos or 

Morrison). The ponds would be constructed one at a time, as needed, during the 100-year 

operational life of the unit. As each one is filled with salt deposits, it would be covered with earth 

and seeded, and a replacement pond would be developed. 

A Hydrogen Sulfide stripping plant would be included, and it is assumed that the existing 

collection well and conveyance system would have the pumping capability to deliver the 

collected brine to the nearby evaporation basins. 

Measures to prevent waterfowl from using the ponds may need to be included. One possible 

approach would involve installation of netting over the ponds, similar to that used in the Imperial 

Valley commercial fish rearing ponds. 

Preliminary cost estimates indicate that cost for this alternative will be in the acceptable range. 

This alternative should be further evaluated in phases 3 and 4. 
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April 08 24 of 28 

Alternative 11: Agricultural Land Management 

Description of Alternative 

This alternative proposes a five year demonstration program to be conducted, where those 

irrigated farmlands nearest to the Dolores River would be leased and used for wildlife habitat 

purposes. To retain the agricultural viability of those lands, the lands would be tilled and a single 

irrigation would be applied each year to establish a wildlife supportive cover crop. 

There are about 1,100 acres of West Paradox Valley irrigated farmland within about two miles of 

the Dolores River. It is estimated that deep percolation from these farmlands amounts to about 

1.0 acre-feet per acre, or 1,100 acre-feet per year. Based upon analysis of flow and salt loading 

from the West Paradox Creek agricultural area, placing these lands in a conservation reserve 

would reduce deep percolation into the saline aquifer by about 14% thereof, or 154 acre-feet per 

year. 

The program could be modeled after the USDA Conservation Reserve Program with annual 

payments of $500 per acre. Preliminary cost estimates indicate that the cost per ton of salt 

removed is within the acceptable range. This alternative should be retained for further 

evaluation. 
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April 08 25 of 28 

Alternative 12: Add Liner to West Paradox Creek Wetlands 

The 300 acre West Paradox Valley wetland pond nearest to the Dolores River would be lined 

with clay, butyl rubber, HDPE or plastic membrane. To prevent damage from grazing cattle, the 

pond area would be excavated when dry to a depth of two feet, the liner installed, and the 

excavated material replaced over the liner. The volume of excavated material would be about 1 

million cubic yards. After more in-depth investigation, it may be found that the entire pond may 

not need to be lined and/or a local clay formation may provide the needed water-tight material. 

Water is maintained in Pond 3 for about 100 days per year. When water has been in the pond, an 

incremental additional Dolores River salt load of 50 tons per day has been observed. 

Accordingly, lining Pond 3 may be able to prevent as much as 5,000 tons per year from entering 

the Dolores River. 

Preliminary cost estimates indicate that synthetic liners would exceed the acceptable cost per ton 

of salt removed. However, if a locally available source of clay can be found the cost may 

become acceptable. This alternative is not recommended for further evaluation. 
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April 08 26 of 28 

Alternative 14: Integrated Evaporation Pond and Treatment 

Approaches 

Overall Concept – Under this alternative, the fluid being pumped into the injection well would 

be concentrated to 300,000 mg/l. About 72 acre-feet per year of fluid from the higher salinity 

(260,000 mg/l) collection wells would be delivered to the injection well. An additional 258 acrefeet per year/yr. of collection well pumping would be stripped of hydrogen sulfide and delivered 

to a 2-acre solar gradient pond (SGP) having a depth of 15 feet. The SGP would evaporate about 

2 acre-feet per year of brine and provide the heat energy needed to concentrate and dispose of the 

remaining brine. About 143 acre-feet per year of 320,000 mg/l reject from the brine concentrator 

would be blended with the 72 acre-feet per year of filtered (260,000 mg/l) pumped water, and the 

blend (215 acre-feet per year of 300,000 mg/l brine) containing about 87,000 tons per year would 

be delivered to the existing well for injection. The impact on the injection well of increasing the 

salinity of the injected brine is unknown. There is potential that the higher salinity could destroy 

the well. 

Operation of the Solar Gradient Pond – Of the 258 acre-feet per year of collected brine delivered 

to the SGP, two acre-feet would evaporate. 143 AF/yr. would be returned to the injection well 

and the remaining 115 acre-feet per year would be concentrated to a near solid state. Assuming 

that saturation and crystallization would occur with about 27 percent moisture, approximately 78 

acre-feet per year or about 70,000 GPD of liquid would need to be removed from the brine. 

Removal of this volume of liquid would require about seven (7), 10,000 GPD Dewvaporation 

Units. 

Operation of the Brine Concentrator – The 2-acre solar gradient pond could produce about 200 

GPM of 185o F brine. Total flow to the seven Dewvaporation Units would be 210,000 GPD or 

about 150 GPM, of which one-third would evaporate and two thirds would become reject water. 

Although it may be possible to recapture the 78 acre-feet per year of the evaporated fluid as 

distillate, such collection may become problematic and, for the purpose of this analysis, it is 

assumed that the saturated vapor from the Dewvaporation units is vented to the atmosphere. 

Program Features 

Based upon a Navajo Generation Station crystallizer proposal submitted to Reclamation in early 

2004, such a system would have the following components: 

• Two acre Solar Gradient Pond with Piping; 

• Seven 10,000 GPD Dewvaporation Units; 

• One 2,500 square foot process building; 

• 0.4 acres of Right-of-Way; 

• 0.2 equivalent person years of O&M labor; 

• Land fill for 21,000 tons per year of salt disposal 
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Alternatives 4 and 5 contemplate the use of zero liquid discharge (ZLD) technology and 

Dewvaporation to reduce the collected brine to a solid state to be disposed in a permitted land 

fill. These alternatives need electric power and heat energy for their operation. 

Solar gradient evaporation ponds collect heat at the bottom of the pond through a fluid inversion 

process, where the heavier brines settle to the lower level of the pond and collect the available 

atmospheric and solar heat energy. Such ponds typically provide process heat at near boiling 

stage while evaporating water from the surface as a conventional solar evaporation pond. 

The integration of the ZLD technology, with a small solar gradient evaporation pond to provide 

heat energy to further concentrate the brine along with continued use of the existing injection 

well, could provide potential to remove additional salt from the Dolores River without increasing 

the volume of injected brine. 

This alternative should be carried forward for further evaluation. 
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April 08 28 of 28 

Consultation, Coordination and Selection of Phase 3 and 4 

Alternatives 

After completing the technical evaluation of the alternatives it is recommended that the 

following alternatives be evaluated further as part of Phases 3 and 4. 

• Alternative 1: Enhance existing injection system; 

• Alternative 2: Additional injection well; 

• Alternative 3: Divert West Paradox Creek; 

• Alternative 4: Zero Liquid Discharge; 

• Alternative 5: Dewvaporation; 

• Alternative 6B: Vibratory Shear Enhanced Process; 

• Alternative 9: Conventional evaporation basins; 

• Alternative 11: Agricultural land management; and 

• Alternative 14: Integrated evaporation pond and treatment approaches. 

The alternatives removed from further consideration were technically unfeasible or preliminary 

cost estimates indicated costs greater than $200/ton of salt removed. 
P HASE 2 T ECHNICAL M EMORANDUM – E VALUATE T ECHNICAL M ERIT OF A LTERNATIVES 

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ATTACHMENT A 

DATA 
P HASE 2 T ECHNICAL M EMORANDUM – E VALUATE T ECHNICAL M ER

P ARADOX V ALLEY S AL

April 08 
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April 08 

MEMORANDUM 

 

06/09/06 

To: File 

From: Andy Nicholas, Facility Manager 

 Paradox Valley Unit (PVU) 

Subject: Private Ponds/Wetlands on West Side of Dolores River – Paradox Valley, Colorado 

During investigations for salinity control at Paradox Valley in the 1970’s, salt loading in the 

Dolores River at Paradox Valley averaged 500 to 600 tons per day (PVU Final Environmental 

Statement, pg. B16, March 1979). In 1993, during the injection test to determine the rate at 

which Paradox Valley Brine could be disposed in the injection well, salt loading in the Dolores 

River averaged 345 tons per day according to available USGS data. As the injection test 

progressed and eventually, as the plant was brought into full production, the average daily salt 

load was reduced to 180 tons per day in 1999. During this period, the area across and slightly 

upriver from the upper well field was a natural wetland as the water from West Paradox Creek 

diffused from the creek’s main channel and spread over a relatively large area near its confluence 

with the Dolores River. 

From 1998 to 2004, western Colorado experienced below normal precipitation (Figure 1) which 

depleted the amount of West Paradox Creek water from reaching the wetland area and 

consequently caused the area to dry out. During that period, a general decline in Dolores River 

conductivity was observed (Figure 2). 

Paradox, Colorado Ann. Precip (in)

0

2

4

6

8

10

12

14

16

18

1996 1997 1998 1999 2000 2001 2002 2003 2004 2005

Year

Annual Precip (in)

Annual Precip (in)

Avg. Ann. Precip 1977 to 2005

 Figure 1 

In late 2003, a land owner on the west side of the Dolores River constructed a series of shallow 

ponds in the wetland area. During that time salt loading at Paradox Valley was estimated at less 
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April 08 

than 50 tons per day (Figure 2). In early 2004, water from West Paradox Creek was diverted 

into the ponds, filling the ponds with water. Concurrently, an increase in conductivity in the 

Dolores River was observed (Figure 2). In March of 2004, as the irrigation season began, water 

was diverted before reaching the ponds and they dried up. As the ponds dried up, the 

conductivity in the river returned to very low readings. 

After the irrigation season in late 2004, the ponds were again filled with water and again the 

conductivity increased significantly in the river. The winter of 2004/2005 was one with above 

average precipitation which provided abundant water resources throughout the 2005 irrigation 

season and allowed the ponds to remain full all summer. The ponds have remained full during 

the 2005/2006 winter and the conductivity in the river has not returned to the low levels observed 

during periods when the ponds/wetlands were dry. 

Monthly Salt Loading

0

100

200

300

400

500

600

700

Oct-93

Feb-94

Jun-94

Oct-94

Feb-95

Jun-95

Oct-95

Feb-96

Jun-96

Oct-96

Feb-97

Jun-97

Oct-97

Feb-98

Jun-98

Oct-98

Feb-99

Jun-99

Oct-99

Feb-00

Jun-00

Oct-00

Feb-01

Jun-01

Oct-01

Feb-02

Jun-02

Oct-02

Feb-03

Jun-03

Oct-03

Feb-04

Jun-04

Oct-04

Feb-05

Jun-05

Oct-05

Feb-06

Month/Year

Daily Average (t/d)

Salt Loading in tons per day

 Figure 2 

There appears to be a direct correlation between increased salinity observed in the river and both 

the natural wetlands that previously existed and water in the ponds. The appearance is that the 

natural brine aquifer below the wetland/ponds is being raised and commingling with the fresh 

West Paradox Creek water. As the level of the aquifer is raised it may be allowing additional 

brackish discharge into the Dolores River. 

The wetland that existed prior to construction of the ponds and now the ponds may be 

contributing a substantial amount of salt to the river by elevating the local aquifer. It would 

benefit the CRBSCP, downstream users, and the landowner to find a solution if a relationship 

does exist between the ponds/wetland and increased salt load in the river. 
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April 08 

MEMORANDUM 

 

06/14/06 

To: Files 

From: Andy Nicholas, Facility Manager 

 Paradox Valley Unit (PVU) 

Subject: Private Ponds/Wetlands on West Side of Dolores River 

On April 24, 2006, I contacted Rick Schnaderbeck, FWS, regarding information on the nature of 

the grant that funded construction of the ponds on Greg Irwin’s property across the river from the 

Upper Well Field. I explained to Rick my suspicion of a correlation between increased salinity 

in the river when water was diverted into the ponds. We discussed my theory of the water 

leaking from the ponds thereby elevating the brackish aquifer and promoting additional 

discharge into the Dolores Riverbed. Rick asked if I would like to have a meeting or conference 

call with FWS, BOR and the landowner and I suggested that I talk to Greg Irwin first to 

determine his interest in conducting a test. The test would be to essentially allow the ponds to 

dry out in order to observe any apparent correlation of salinity reduction in the river. 

A couple of days later I spoke with Greg Irwin and he agreed to divert the water from the pond 

closest to the river, since that pond seems to have the greatest influence on the changes in river 

salinity. 

On approximately May 1, 2006, I observed the level in the ponds and they were full. 

I again observed the ponds on May 12 and noted that the levels in all three ponds had dropped 

significantly. 

On May 22, I noted that the easternmost pond, the pond closest to the river was dry. The other 

two pond levels were approximately the same level or slightly lower than on May 12. 

Each month I use the attached spreadsheet to calculate estimated salt loading in the Dolores 

River through Paradox Valley. The two sites measuring the electrical conductivity are USGS 

operated and maintained stations. Site 009EC is located at the Bedrock Bridge as the river enters 

the valley. Site 090EC is located in the canyon north of the valley as the river exits the valley. 

Historically, as the river stream flow decreases, salt loading increases. Since May 1, the stream 

flow has decreased from approximately 110 cfs to approximately 75 cfs on May 25, yet the salt 

loading is decreasing, which indicates an apparent correlation between the easternmost pond 

drying up and salt loading in the river. 
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April 08 

On June 12, I noted that the easternmost pond, the pond closest to the river was dry, the middle 

pond was almost completely dry, and the westernmost pond still had some water, but was very 

low. 

On June 9, the estimated salt pickup through Paradox valley was 72 tons per day. On June 13, 

the estimated salt pickup was 55 tons per day. 

The USGS had equipment problems from June 1 through June 8, so the data from EC090 for that 

period is lost. 
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April 08 

Figure A-2 

West Paradox Creek 1944-52 Average Monthly Flow

0

100200300400500600700

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Month

Average Acre-feet per Month 

West Paradox Creek nr Bedrock 00060, Discharge, Acre-feet per Month 
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Figure A-3 

Figure A-4 
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Figure A-5 

Figure A-6 
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Figure A-7 

Figure A-8 
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Figure A-9