PHASE 3 AND 4 TECHNICAL MEMORANDA 

EVALUATION OF SALINITY CONTROL 

ALTERNATIVES ENVIRONMENTAL AND 

ECONOMIC FEASIBILITY 

for 

 PARADOX VALLEY 

SALINITY CONTROL UNIT 

 by 
P HASE 3 AND 4 TECHNICAL MEMORANDUM – EVALUATE E NVIRONMENTAL AND E CONOMIC FEASIBILITY

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Table of Contents 

Introduction ....................................................................................................................................1 

Alternatives Eliminated From Further Evaluation in Phase 2 ..................................................1 

 Alternative 6A: SAL-PROC .....................................................................................................1 

 Alternative 13: Line West Paradox Creek Wetlands ...............................................................2 

Phase 3 and 4 Evaluation Methodology .......................................................................................2 

Alternative 1: Enhance Existing Injection System ....................................................................3 

Alternative 2: Additional Injection Well ....................................................................................6 

Alternative 3: Divert West Paradox Creek ................................................................................8 

Alternative 4: Zero-Liquid-Discharge ......................................................................................12 

Alternative 5: Dewvaporation ...................................................................................................23 

Alternative 6: Other Innovative Treatments ...........................................................................25

 Alternative 6B: Vibratory Shear Enhanced Process (VSEP) .................................................25 

Alternative 9: Conventional Evaporation Basins ....................................................................27 

Alternative 11: Agricultural Land Management ......................................................................31 

Alternative 14: Integrated Evaporation Pond and Treatment Approaches ...........................32 

Summary of Findings ..................................................................................................................34 
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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, 9 were evaluated for technical merit. During the 

evaluation of technical merit, Alternative 6A, SAL-PROC, and Alternative 12, Line West 

Paradox Creek Wetlands, were eliminated from further evaluation. This technical memorandum 

will justify the elimination of Alternatives 6A and 12 as well as discuss the environmental and 

economic feasibility of the remaining 10 alternatives. Utilizing the numbering system used in 

the Phase 1 Technical Memorandum, 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 6B: Vibratory Shear Enhanced Process; 

• Alternative 9: Conventional evaporation basins; 

• Alternative 11: Agricultural land management; and 

• Alternative 14: Integrated evaporation pond and treatment approaches. 

Alternatives Eliminated From Further Evaluation in Phase 2 

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 

alternatives, refer to the sections on Constraints in the Phase 1 Technical Memorandum for more 

complete information. 

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 more marketable 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). 

Due to the problems implementing the process in Australia and the limited amount of more 

marketable products in the Paradox brine, the SAL-PROC process does not appear to be 

technically or economically viable for the Paradox project. 
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Alternative 13: Line West Paradox Creek Wetlands 

The wetlands and wildlife ponds adjacent to the Dolores River in the brine inflow area cover 

hundreds of acres. Lining such a large area to reduce, but not eliminate, the salt loading will not 

be economically feasible. Alternative 3, Divert West Paradox Creek, can accomplish the same 

results at a much lower cost. Thus, this alternative has been dropped from further consideration. 

If diversion of West Paradox Creek is infeasible, some benefit may be derived from limiting the 

time the wildlife ponds are filled prior to the migration season. Currently the wildlife ponds are 

filled whenever there is water in West Paradox Creek. Limiting the time the ponds are filled will 

limit the time that recharge of the aquifer is occurring. Thus, reducing brine inflow. 

Phase 3 and 4 Evaluation Methodology 

The approved “Approach to the Work” for Phases 3 and 4 provides that the FCE team will 

evaluate each candidate alternative for environmental and economic feasibility. To accomplish 

this objective, the remaining candidates were configured in a preliminary manner to identify the 

environmental issues associated with the alternative and the cost of implementing each 

alternative. 

Environmental Feasibility Evaluation 

FCE team members have contacted local, county, state, and federal agencies to determine the 

environmental issues associated with the various alternatives. The environmental issues 

identified for each alternative will be discussed in the body of this report. The general 

environmental impacts of the existing facilities are discussed as part of Alternative 1. 

Environmental issues related to the alternatives will only be discussed if they vary from the 

issues already addressed in Alternative 1. The relative ease or difficulty related to addressing the 

environmental issues will also be discussed in the evaluation. 

Economic Feasibility Evaluation Methodology 

An appraisal grade cost estimate has been prepared for each alternative to assess the relative 

merits of the various alternatives. The appraisal grade cost estimate includes: the capital costs 

associated with constructing the facilities associated with each alternative, the permitting and 

environmental mitigation costs estimated based on the environmental feasibility evaluation, and 

30% of the capital costs for contingency and engineering. To allow comparison of the current 

brine disposal system to the alternatives, the capital costs are based on the cost to dispose of 230 

gpm of brine (310 acre-feet), and/or 109,000 tons/year of salt. Some of the alternatives can be 

expanded to treat a larger volume of brine than is currently being injected. Some of the 

alternatives do not treat the brine but will reduce the volume of brine to be treated and/or 

improve the efficiency of brine treatment alternatives. For these alternatives, the cost and the 

salt reduction have been estimated and a cost per ton of salt removed was calculated. In 

association with the capital costs, the annual operation and maintenance costs have been 

estimated for each alternative. 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, 
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as provided in Reclamation’s Federal Register Notice1 dated November 16, 2007, to determine 

an annualized cost of capital. The annualized cost of capital plus annual O&M cost was then 

used to compare the current system to the alternative. The operation and maintenance costs for 

the current system are approximately $2.9 million. The alternatives that utilize the current 

extraction system will include a portion of the operation and maintenance costs. It is estimated 

that approximately $300,000 of the O&M costs are associated with the extraction system. 

Alternative 1: Enhance Existing Injection System 

This alternative represents the baseline by which the other alternatives being evaluated can be 

compared. The only enhancement to the current operation that has been identified is to 

concentrate the brine further before injection. The costs and environmental issues associated 

with the process to concentrate the brine will be discussed in other alternatives. The costs and 

environmental issues identified here are for the current operating conditions for the system. 

Namely, a brine injection rate of 230 gpm (310 acre-feet) and an average salt disposal of 109,000 

tons. 

Environmental Feasibility 

When developing a plan for the control of brine inflow to the Dolores River in the Paradox 

Valley, the Bureau of Reclamation (BOR) originally intended to use a large evaporation basin. 

In addition to local opposition for the plan, the EPA recommended that deep well injection be 

used for brine disposal. Given the local opposition and EPA’s recommendation, the current deep 

well injection system was built. 

Environmental issues addressed in relation to the current system include: 

Groundwater Quality. Whenever brine is injected into an aquifer there is concern that it may 

adversely impact a fresh water aquifer. The Leadville formation, where the brine is to be 

injected, already contains brine with a TDS of approximately 218,000 mg/l. The water in 

Leadville formation is unusable and injection of brine will only slightly increase the salinity of 

the in-situ water located 15,000 feet below the surface. The depth and isolation of this formation 

render migration of the brine to usable aquifers virtually impossible. The BOR obtained a Class 

V injection well permit pursuant to Underground Injection Control Regulations of the 

Environmental Protection Agency (EPA). To obtain this permit, BOR had to demonstrate that 

brine injection would not adversely impact fresh water aquifers. Near surface groundwater 

quality will not be impacted by deep injection. 

Water Rights. Extraction of brine adjacent to the Dolores River reduces the inflow to the river. 

As a result of the depletion to the river, caused by the extraction of brine, a water right has been 

obtained by BOR. In 1972, the BOR obtained a conditional water right for 4.94 cfs. This water 

 

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

(Volume 72, Number 221, Page 64669]
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right has a priority associated with it. The priority of the water right will not allow continuous 

extraction. To compensate for the priority of the water right, BOR prepared an augmentation 

plan that would store water in McPhee Reservoir for release when depletions to the Dolores 

River occurred due to out-of-priority pumping of the brine extraction wells. The water right in 

McPhee Reservoir is for 700 acre-feet. Since current pumping is limited to 230 gpm (0.42 cfs), 

310 acre-feet adequate water rights for the depletion to the Dolores River are in place. 

Surface Water. Operation of the unit will cause a depletion to the Dolores River of 230 gpm or 

310 acre-feet under current operating conditions. As mentioned above, BOR has water rights for 

this depletion. Operation of the Paradox Unit does not impact flow or water quality in the East 

or West Paradox Creeks. In the past, fresh water from the Dolores River has been pumped for 

mixing with the brine prior to injection. Fresh water extraction from the Dolores River is not 

currently occurring but may occur in the future. McPhee Reservoir was constructed on the main 

stem of the Dolores River upstream of the Paradox Valley in 1985 and provides mitigation for 

the small depletions resulting from the Paradox Unit. In 1996, BOR obtained additional water 

for release from McPhee Reservoir downstream to the Dolores River. These releases will more 

than offset the small depletion caused by operation of the Paradox Unit. The Paradox Unit does 

not discharge to the Dolores River or its tributaries. Therefore, surface water quality will not be 

degraded as a result of the unit. Water quality of the Dolores River is improved due to the 

extraction of the brine prior to its flow into the river. 

Vegetation. Construction of the current facilities resulted in some permanent impacts. Small 

areas around wells, access roads, areas around the surface treatment building, and injection well 

facilities have the vegetation permanently removed. Other areas impacted by construction have 

been revegetated. The small depletion of groundwater inflow to the Dolores River has been 

replaced by releases from McPhee Reservoir. Removing some of the brine may result in fresher 

water being available for riparian vegetation in the brine inflow area. No further impacts to 

vegetation are expected from the operation of the unit. 

Wetlands and Riparian Habitats. The most significant wetland habitat is located across the river 

from the brine well field on the west bank of the Dolores River. This wetland is dominated by 

tamarisk and is situated along the river and lower portions of West Paradox Creek. The wetland 

is supported by saturated soils resulting from the meandering of West Paradox Creek, summer 

storm runoff, snow melt, agricultural runoff, and possibly groundwater flowing from West 

Paradox Valley. Pumping brine from the east side of the river has not appeared to impact 

wetlands on the west side of the river. Removal of brine may actually improve the water quality 

of the groundwater supporting the wetlands. 

Fisheries. Operation of the unit will deplete the flow in the Dolores River. However, releases 

from McPhee Reservoir will compensate for the small amount of inflow to the river prevented by 

pumping the brine. Removing some of the salt loading to the river will improve water quality 

thereby improving the fish habitat. Operation of the unit will improve the fishery. 

Wildlife. Impact of the project on wildlife is limited to the disruption caused by human activity 

as a result of operating the unit on a long term basis. The small depletion to the Dolores River is 
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compensated for by releases from McPhee Reservoir. The small footprint of the current system 

does not impact access to the river by wildlife and has caused little reduction of habitat. 

Threatened and Endangered Species. The May 1997 DPR identified 10 threatened and 

endangered species that could be impacted by the Paradox Valley Unit. The BOR did not find 

any impact due to the project on any of the identified threatened and endangered species. The 

Fish and Wildlife Service (FWS) did not agree with BOR assessments relative to the endangered 

fish in the Colorado River. The Fish and Wildlife Service concluded that the Paradox Unit 

would jeopardize the continued existence of the Colorado Squawfish, humpback chub, bonytail 

and razorback Sucker resulting in the destruction or adverse modification of their critical habitat. 

The FWS conclusions are based on the assumption that any depletion to the Colorado River will 

adversely affect these endangered fishes. However, the FWS concluded that because the average 

depletion was less than the sufficient progress threshold, participation by BOR, i.e. payment of 

fees, in the Colorado River Recovery Implementation Program would mitigate the impact of the 

unit. BOR continues to disagree with the FWS, that operation of the unit would deteriorate water 

quality in the Colorado River, since the operation of the unit prevents over 100,000 tons of salt 

from entering the Colorado River. FWS has not altered its position since the Environmental 

Assessment (EA) was completed in 1997. FWS was contacted and indicated that the Black 

Footed Ferret (listed as endangered), Gunnison’s prairie dog (listed as endangered), and the 

Yellow-billed cuckoo (listed as a candidate species) may be present in the Paradox Valley. The 

status of the Gunnison Sage Grouse is currently in litigation and may be listed depending on the 

outcome of the lawsuit. FWS does not believe the Southwest Willow Flycatcher is in the area. 

Cultural Resources: During permitting of the unit, several sites were identified on the lands 

acquired by BOR that are eligible, or may be eligible, to be on the national Register of Historic 

Places. The facilities associated with the unit were designed to avoid impacting any 

archaeological and historic properties. BOR and the Colorado State Historic Preservation 

Officer agreed that no effect on cultural resources would occur as a result of the construction, 

operation or maintenance of the unit facilities. 

Air Quality: The extracted brine contains hydrogen sulfide. The current system is not closed 

and approximately 350 lbs/year is released to the atmosphere. The state of Colorado does not 

currently regulate this release. However, there is potential that this release may be regulated in 

the future. 

Indian Trust Assets: There are no Indian Trust Assets in the Paradox Valley. 

Environmental Justice: Analysis conducted as part of the 1997 EA indicated the minority and 

low-income groups would not be adversely impacted by the Paradox Unit. 

All necessary permitting and mitigation efforts have been completed for the construction, 

operation and maintenance of the current Paradox Salinity Control Unit. 
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Economic Feasibility 

In September 2003, the capital cost associated with the current brine injection system was 

identified to be $66,302,211. This is the most recent capital cost available. This capital cost 

includes the permitting, mitigation, and engineering costs, in addition to the cost of the extraction 

wells, injection wells, and associated facilities. Assuming a 30-year life span and 4.875% 

interest rate, the capital recovery cost is $4.25 million/year. The current system operation and 

maintenance cost is approximately $2.9 million annually. Operation of the unit began in 1996 

and is expected to have a 30-year life span. Based on this information, the annualized cost of the 

system is $7,152,000/yr. Using the average salt removal tonnage, since the injection rate was 

reduced to 230 gpm, of 109,000 tons/year, the cost per ton of salt removed is $65.61/ton. 

Alternative 2: Additional Injection Well 

A second injection well was anticipated when the deep well injection plan was being developed 

and implemented. However, the cost of the first injection well precluded installation of the 

second injection well at that time. 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. The second well 

should not be hydraulically connected to the first injection well site due to faulting between the 

two sites. 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. Approximately two miles of 10-inch HDPE pipeline is 

anticipated, plus a directional-drilled river crossing. 

Environmental Feasibility 

The environmental issues and impacts related to Alternative 2 have already been addressed and 

are expected to be similar to those previously delineated for Alternative 1 (Existing Injection 

System). With an additional injection well, inducing micro earthquakes is likely to occur. The 

magnitude of these additional earthquakes is predictable but unknown. Mitigation could be 

similar to activities with the existing well, including reduced injection rates and periodic resting. 

The EA for the existing system will need to be updated to reflect the second injection well but 

the effort required should be much less than needed for the original EA. New facilities 

associated with a second well will be a pipeline to connect the surface treatment facilities to the 

new injection well and the facilities associated with the injection well. Only the environmental 

issues related to these new facilities are addressed below. 

Groundwater Quality. Whenever brine is injected into an aquifer there is concern that it may 

adversely impact a fresh water aquifer. The second injection well will discharge into the same 

formation as the current injection well. The BOR will need to obtain a Class V injection well 

permit pursuant to Underground Injection Control Regulations of the EPA for the second 

injection well. With all of the information available on the first injection well, it should not be 

very difficult to obtain an injection permit. 
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Water Rights. Extraction will not exceed current water rights even with a second injection well. 

No water rights issues are anticipated. 

Surface Water. A second injection well will not alter operation beyond what is already 

permitted. However, the pipeline connecting the surface treatment facility to the second 

injection well may cross under the Dolores River. The river crossing will require a Section 404 

permit from the Army Corps of Engineers. This permit should not be very difficult to obtain. 

However, the actual underground 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. If costs allow, an overhead crossing of the 

Dolores River may be used to eliminate these problems. 

Vegetation. Vegetation will be temporarily impacted by pipeline construction. The injection 

well facilities will be on land previously disturbed by oil drilling so significant vegetative 

impacts are not expected. . 

Wetlands and Riparian Habitats. Pipeline construction will impact riparian areas adjacent to the 

river. The impact will be temporary and will be addressed in the Section 404 permit for the river 

crossing. 

Fisheries. Impact on fisheries should not change from the current situation. 

Wildlife. Impact of the project on wildlife is limited to the disruption caused by human activity 

as a result of operating the unit on a long term basis. The small footprint of the second injection 

well will not impact access to the river by wildlife and will cause little, if any, reduction of 

habitat. 

Threatened and Endangered Species. No additional threatened and endangered species issues 

are expected as a result of a second injection well. 

Cultural Resources: A cultural resources survey will need to be conducted prior to any 

construction. Any sites identified will need to be avoided. 

Air Quality: Hydrogen sulfide will be handled in the same manner as it is in the existing system. 

The addition of a second injection well appears to be environmentally feasible. 

Economic Feasibility 

Capital facilities for an additional injection well system would include: 

• Second injection well (assumed to be an 51⁄2-inch bore to a depth of 16,850 feet); 

• Second wellhead; and 

• Additional surface facilities to test well and pipeline. 
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The existing extraction wellfield and pipeline have sufficient capacity to supply two injection 

wells, and expansion and/or upgrading is not required. Although some minor expansion of the 

extraction system may improve unit efficiency. 

If the second well replaces the current well, the capital costs, including contingencies and 

engineering, are projected to be about $84.4 million (2008 dollars). Annualized over 30 years at 

4.875% interest, capital recovery is approximately $5.41 million/year. Annual O&M costs are 

projected to be about $2.9 million/year. Resultant total annual cost would be $8.31 million/year. 

The resultant unit cost of salt removal, at 109,000 tons/year, is $76.2/ton. 

Existing injection pressure falloff data and analysis suggest that a second injection well operated 

alternately with the existing injection well would prolong the life of each well thereby reducing 

the annualized cost. If the second injection well is installed to operate in conjunction with the 

existing well, the additional capital costs will be the same $84.4 million. However, if the wells 

are alternately operated, the life expectancy of the wells will more than double. For this study it 

is assumed that the life expectancy of the wells will be 60 years to be conservative. Annualized 

over 60 years at 4.875% interest, capital recovery is approximately $4.37 million/year. Since the 

two wells will be operated alternately, the power costs, staffing costs, and part replacement costs 

should not change dramatically. The total cost to operate both wells and extraction facility is 

approximately $3 million/year. Resultant annual cost would be $7.37 million/year. The 

resultant unit cost of salt removal, at 109,000 tons/year, is $67.6/ton. 

Alternative 3: Divert West Paradox Creek 

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. Combinations of creek bypass and reduction of agricultural recharge are also 

possible. By reducing West Paradox Valley recharge, the brine flowing into the river may be 

reduced dramatically. 

It may appear that further evaluation of this alternative contradicts the decision to not evaluate 

Alternative 16, Fresh Water Cutoff Wells, further due to difficulties understanding the regional 

hydrogeology. However, there are two major differences between the two alternatives. The first 

is the difference between understanding the regional groundwater system and understanding the 

local groundwater system. The success of Alternative 16 relied upon understanding where water 

from the regional aquifer interacts with the salt dome to produce brine. Little if any data is 

available to determine this. Data has been collected within the Paradox Valley that provides 

some understanding of the groundwater system in the valley. Previous groundwater studies have 

focused on the local rather than the regional system. The second difference is that we can 

identify the sources of fresh water recharge in the Paradox Valley and eliminate some of them, 
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such as leaking ditches and canals, at the surface. Intercepting regional groundwater will require 

deep wells and expensive studies to identify where to put the wells. Controlling freshwater 

recharge in the Paradox Valley has a much greater chance of success than finding and extracting 

fresh water in the regional aquifer before it contacts the salt dome. 

There are four possible configurations of this Alternative, as follows: 

3(A) Piping West Paradox Creek through the reach where it spreads across a large area and 

recharges the aquifer adjacent to the Dolores River; 

3(B) Replacement of the current system of open ditches and ponds with a pressurized 

irrigation system, ; 

3(C) Piping West Paradox Creek from the existing diversion dam at the west end of the valley 

and conveying the water to the Dolores River near the existing highway bridge. ; and, 

3(D) Piping West Paradox Creek from the existing diversion dam at the west end of the valley 

and conveying the water to the Dolores River near the existing injection well along with 

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

irrigation system. 

The environmental feasibility of these four configurations is similar and is discussed below. 

Environmental Feasibility 

Technically this alternative is simple. However, it creates many challenging environmental 

issues and an Environmental Impact Statement (EIS) will need to be prepared. The 

environmental issues related to this alternative are identified below. 

Groundwater Quality. The point of this alternative is to reduce fresh water recharge in the area. 

With the reduction in fresh water recharge, the groundwater levels are expected to drop. The 

reduction of fresh water recharge is also expected to increase the salinity of the fresh 

groundwater near the surface. Groundwater inflow to the river, and thereby brine inflow to the 

river, will be reduced. 

Water Rights. Piping West Paradox Creek may actually increase the volume of fresh water 

flowing into the Dolores River by reducing the evaporation losses. Water rights on West 

Paradox Creek will be met through deliveries from the creek bypass facilities. Therefore, West 

Paradox Creek water rights would not be impacted. 

Surface Water. Modifications to West Paradox Creek and at the outlet to the Dolores River will 

require working with the Army Corps of Engineers to obtain a Section 404 permit. Unlike other 

states, the State of Colorado relies exclusively on the Army Corps of Engineers to regulate all 

activities that impact streams, creeks or rivers. Under this alternative, all flow in West Paradox 

Creek, other than high flow events, would be diverted into the pipeline. 
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Domestic Water Supplies. Water supplies for some homes and businesses in the West Paradox 

Valley are derived from local domestic wells. A program to reduce leakage from canals, ditches, 

and farm fields may adversely affect those wells. Depending upon the option selected, it may be 

necessary to integrate development of a rural domestic water system into this alternative. 

Depending upon ability to pay and other factors, the local community may be able to assume a 

part of the cost of such a system. 

Vegetation. Diverting West Paradox Creek will reduce or eliminate the water supported 

vegetation areas along the creek. Under provisions of the Fish and Wildlife Coordination Act, 

this loss of vegetation will need to be mitigated. 

Wetlands and Riparian Habitats. Diverting West Paradox Creek will dry up an unknown portion 

of the wetlands at the lower end of the creek adjacent to the Dolores River. Under provisions of 

the Clean Water Act and the Fish and Wildlife Coordination Act, this loss of wetlands will need 

to be mitigated with in-kind replacement of an equivalent acreage of comparable quality 

wetlands. The replacement wetlands would need to be located in an area where leakage would 

not cause salt loading to the Dolores River. 

Fisheries. West Paradox Creek is diverted completely for irrigation during the irrigation season. 

However, return flows keep water in sections of the creek year round. Due to sections of the 

creek being dry for much of the year, West Paradox Creek is not likely to support a year round 

fish population in the area impacted by this alternative. Fish from the Dolores River or from 

perennial areas above irrigation diversions may use sections of the creek that would be impacted 

by this alternative when water is available. These potential impacts will need to be addressed in 

an EA/EIS. Flows in the Dolores River may increase slightly due to the diversion of West 

Paradox Creek thus, improving the Dolores River fishery. 

Wildlife. Any wildlife that uses the wetland and riparian vegetation will be impacted by the 

diversion. Impacts to wildlife will need to be identified in an EIS and may need to be mitigated. 

Threatened and Endangered Species. Because this alternative will impact flows in a tributary to 

the Colorado River and will impact wetlands, threatened and endangered species become an 

important issue to be addressed in an EIS. BOR participation in the Colorado River Recovery 

Implementation Program will likely address the endangered fish in the Colorado River but not 

any species impacted by changes to wetlands. 

Cultural Resources: A cultural resources survey will need to be conducted prior to any 

construction. Any sites identified will need to be avoided or mitigated. 

Air Quality: This option should have no air quality issues to be addressed. 

The diversion of West Paradox Creek as proposed would create significant environmental 

concerns and require in-kind mitigation of the habitat, wetlands, and species that would be 

impacted. 
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Economic Feasibility 

The construction costs associated with these options will include the cost of environmental 

permitting, studies, and mitigation, which are difficult to quantify at this juncture. 

Option 3(A) -- Diversion of the lower 3,200 feet of West Paradox Creek. The construction and 

permitting costs (with contingencies and unlisted items) are estimated to be $1.3 million 

($300,000 for the actual construction and $1 million for the permitting effort). Operation and 

maintenance costs for the pipeline will be less than $5,000 per year. The expected life of the 

pipeline is 50 years. Based on this information, the annualized cost of the system is $75,000/yr. 

Due to the limited time frame that the creek would be diverted, the reduction in salt loading will 

be less than the 5,000 tons previously estimated although it will still occur during the most 

effective time period. It is estimated that salt loading can be reduced by 4,000 tons/year. Using 

this salt removal tonnage, the cost per ton of salt removed is $18.75/ton. As mentioned before, 

additional measurements should be made to better quantify the reduction in salt loading before 

any permitting or design efforts are made. 

Option 3(B) -- Replacement of the current system of open ditches and ponds with a pressurized 

irrigation system. It is estimated that there are approximately 46 miles of canals and ditches that 

can be replaced by a pressurized irrigation system. The current system serves about 4,000 acres 

of irrigated farmland, mostly (75%) using sprinkler irrigation. Reconstruction of this delivery 

system would cost about $1,000 per acre or $6 million for the entire system (with contingencies 

and unlisted items), including $2 million for the EIS. Operation and maintenance of the system 

will be turned over to the local irrigation company so there should not be any annual Federal 

O&M costs. The expected life of the pressurized irrigation delivery system is 50 years. Based 

on this information, the annualized cost of the pressurized irrigation system would be about 

$322,000/yr. 

Assuming that re-use of tail water and return flow is now being accomplished; deep percolation 

without system improvements is estimated to be about 0.5 acre-feet per acre. Approximately 3 

acre-feet of water is diverted for each of 4,000 acres. This corresponds to about 2,000 acre-feet 

per year of deep percolation. It is assumed that half of the deep percolation could be eliminated 

by system improvements. Assuming 14% of the 1,000 acre-feet becomes brine, a pressurized 

irrigation system could reduce brine inflow by 140 acre-feet. Additional measurements will need 

to be made to validate these assumptions. With brine at 250,000 mg/l, the salt loading can be 

reduced by 48,700 tons/year. Using this salt removal tonnage and the combined annual 

equivalent cost of the pressurized irrigation system ($322,000 per year), the cost per ton of salt 

removed is $6.61/ton. 

BOR has no jurisdiction over the irrigation system in West Paradox Valley. This alternative 

would need to be instituted by the local irrigation company. BOR may encourage the irrigation 

company to pursue salinity control funding for the project but cannot make the irrigation 

company install the improvements. 

Option 3(C) -- Piping West Paradox Creek from the existing diversion dam at the west end of the 

valley and conveying the water to the Dolores River. To accomplish this, a 6-mile, 30-inch 

diameter pipeline would start at the current irrigation diversion structure and discharge near the 
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bridge over the Dolores River. A 30-inch pipe will handle nearly all flows in West Paradox 

Creek except for a few days during spring runoff. The existing channel would still be used for 

these peak flows. The cost to install this proposed system would be approximately $12 million 

(including contingencies and unlisted items). An EIS would add $2 million to the cost, so the 

total construction, engineering, and permitting costs are estimated to be $14 million. Operation 

and maintenance of the system will be turned over to the local irrigation company so there 

should not be any annual Federal costs. The expected life of the pipeline is 50 years. Based on 

this information the annualized cost of the system would be about $752,000/yr. 

Without replacement of the current system of open ditches and ponds associated with irrigation 

activities, the pipeline diversion would be limited to those quantities of water that are not needed 

for downstream irrigation on West Paradox Creek. Current diversions for irrigation dry up West 

Paradox Creek at the upper and lower ends. Assuming that the natural channel would handle 

only the infrequent flood flows and non-irrigation flows, excess water entering the wetlands 

along the Dolores River would be prevented, resulting in a salt load reduction of about 8,000 

tons per year. Using this salt removal tonnage and the annual equivalent cost of the pipeline 

($752,000 per year), the cost per ton of salt removed is $94/ton. 

This option would require coordination with the local irrigation company since BOR has no 

jurisdiction over the diversion structures in West Paradox Creek. The diversion pipeline design 

would also need to address all water rights downstream of the initial diversion. 

Option 3(D) -- Piping West Paradox Creek from the existing diversion dam at the west end of the 

valley to the Dolores River along with replacement of the current system of open ditches and 

ponds with a pressurized irrigation system. The combined cost of these two systems (with 

contingencies and unlisted items), including a $2 million EIS would be about $18 million. 

Operation and maintenance of the system would be turned over to the local irrigation company 

so there should not be any annual Federal O&M costs. The expected life of both the pipeline and 

the pressurized irrigation delivery system is 50 years. Based on this information, the annualized 

cost of the diversion pipeline and pressurized irrigation system would be about $967,000/yr. 

The combination of Options 3(B) and 3(C) is estimated to reduce the salt loading by 56,700 tons 

per year. Using this salt removal tonnage and the combined annual equivalent cost of the 

pipeline and pressurized irrigation system ($967,000 per year), the cost per ton of salt removed 

would be about $17.05 per ton. 

BOR would need to work with the local irrigation company as identified in options 3(B) and 

3(C) to institute this option of Alternative 3. 

As previously mentioned, before any permitting or design efforts are made, additional 

measurements should be made to better quantify the reduction in salt loading. Also, the cost of 

permitting and mitigation needs to be better defined, and the impact on domestic wells and the 

need/justification for a rural domestic water system to serve homes and businesses in West 

Paradox Valley need to be assessed. 
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Alternative 4: Zero Liquid Discharge 

Zero Liquid Discharge (ZLD) is being considered as an additional brine disposal approach to 

supplement the existing injection well program. 

The ZLD system would consist of three components: 

1. Brine crystallizer (BC) 

2. Solar power for the BC 

3. Solar gradient pond (SGP) for BC reject disposal, plus supplemental power 

The system would be sized to handle a similar flow as the current operating brine volume of 310 

acre-feet/year (approximately 300,000 gpd, or 200 gpm), and an average salt disposal of 109,000 

tons/year. 

A typical ZLD system includes a concentrator followed by a crystallizer. A concentrator is not 

required in Paradox because the brine is already concentrated to approximately 240,000 mg/l. 

Therefore, the brine can be fed directly into the crystallizer (BC) following pre-treatment for H2S 

removal to prevent BC corrosion. 

For large applications such as this, a forced-circulation, vapor compression crystallizer is 

commonly used. This type of crystallizer operates in an eight step process (see diagram below): 

1. The first step is to feed the crystallizer with highly concentrated water. 
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2. Secondly, this feed water joins recirculating brine and is pumped into a heat exchanger. 

The type of heater exchanger used can vary, but a shell and tube type is common. 

Scaling in the tubes is prevented by keeping the brine under pressure. This pressure is 

provided by flooding of the tubes. 

3. A small amount of recirculating brine is evaporated as it enters the crystallizer vapor 

body. 

4. The evaporation of water from the brine in Step 3 leads to the formation of crystals. 

Brine which is not evaporated (a majority) is then recirculated back to the heater. 

5. The crystals formed in Step 4 are purged from the system and sent to other systems, such 

as a centrifuge or evaporation pond, for further dewatering before disposal. 

6. To remove entrained particles, the vapor produced in the crystallizer vapor body passes 

through a “mist eliminator.” 

7. Once particles have been removed, the vapor is compressed. The compressed vapor is 

used to heat the recirculating brine when it condenses on the shell side of the heater. 

Using energy in this manner eliminates the need for providing the system with excess 

steam. 

8. Clean condensate from the heat exchanger is purged from the system. 

There are several advantages to using this type of crystallizer. One advantage is the automatic 

wash systems and remote graphic controls. Since onsite monitoring is not required, installation 

in remote locations is possible. Another advantage is that crystallizers generally are skidmounted and packaged with auxiliary equipment. Therefore, the installation process tends to be 

easier than other brine disposal options. A third advantage is that crystallizers have been 

installed in many areas of the United States and are a proven technology. 

Cost and energy usage are typically the biggest constraints with ZLD systems since the process 

is energy intensive. A typical crystallizer uses 250 kWh/1000 gal of feed/hour. For a flow of 

200 gpm at Paradox, 3,000 kWh/hr (26,000 MWhr/year) are needed for the crystallizer to 

operate. 

Another requirement of crystallizers is that they need to be cleaned every 4-6 weeks. This 

involves purging the volume in the crystallizer body to a storage tank and flushing the unit with 

service water. This process usually takes between 12-36 hours. A sequential cleaning regime 

could be developed to reduce downtime to about 1%. 

Crystallizers typically have two capacities: 75 gpm and 100 gpm. Either three of the 75 gpm 

crystallizers or two of the 100 gpm crystallizers could be used to meet the 200 gpm flow 

requirement. It is recommended to use two 100 gpm units, and apply a 95% plant utilization 

factor (PUF) to allow downtime for cleaning and preventive maintenance. As shown on the 

attached layout, dimensions are approximately 62’ by 64’. Since two of these units are necessary 
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to treat the current capacity, the total area required for crystallizers is about 11,000 sf, including 

space for a cleaning storage tank. 

Solar Power for the ZLD System 

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 the ZLD system is approximately 3 MW. For continuous operation of the system, 

additional capacity may be needed for both daylight operation and power to be stored in batteries 

for night time usage. 

The Paradox solar complex will need to have three main components: photovoltaic cells, 

inverters, and batteries. Each one of these is discussed in detail below. 

Photovoltaic Cells

Photovoltaic (PV) cells directly convert light into electricity. They are made from 

semiconductor materials such as silicon. A thin semiconductor wafer is specially treated to form 

an electric field, positive on one side and negative on the other. When light energy strikes the 

solar cell, electrons are knocked loose from the atoms in the semiconductor material. If 

electrical conductors are attached to the positive and negative sides, forming an electrical circuit, 

the electrons can be captured in the form of an electric current. This electricity can then be used 

to power a load. 

Below is a drawing of a PV module. Sizes listed on this drawing reflect a unit with maximum 

power of 175 watts so multiple modules will be needed for the Paradox system. Based on 

discussions with several vendors, approximately 5 acres are needed per MW. Therefore, a 3 

MW solar complex would require 15 acres of land. 
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The photovoltaic drawing reflects a stationary type module. Efficiency can be increased (15-

20% more energy per year) if a tracker is installed which tilts the rows from side to side 

following the sun. Trackers are not recommended for cold areas, however, because of problems 

that may arise with the freezing of mechanical parts. Therefore, this type of module was ruled 

out for usage in Paradox. 

One constraint with solar power in areas of snow is a decrease in production capacity when the 

panel is covered. One measure taken to combat this is installing panels 2 to 3 feet above the 

ground. Therefore, snow levels must reach this height before they would have an effect on the 

module’s production capacity. Secondly, since the modules have an outside layer of black glass 

and are tilted at approximately a 20° angle, heat is conducted which melts the snow and it is able 

to slide off. Modules are tested and designed to be resistant to hail that is 1 inch thick and up to 

60 mph. Therefore, panels should not be damaged by snow in the Paradox area and production 

will be slightly decreased only when snow pack levels reach above 3 feet. 

 

Inverter

An inverter is needed to convert direct current (DC) into alternating current (AC). The solar 

panels will produce DC current, whereas the concentrating system will need AC power. 

Batteries

Because solar energy is not continuously available (i.e., night time and cloudy days), storage is 

an important issue. 

The most widely utilized method for energy storage is batteries. There are several types of 

batteries currently in use: 

• Lead-acid battery 

• Zinc bromine 

• Sodium sulfur 

• Nickel cadmium 

• Vanadium redox 

Based on efficiency levels and experience history, only the lead-acid battery appears viable for a 

Paradox solar system. 

Lead-Acid Battery

Lead-acid batteries are the most common in PV systems because the initial cost is lower and they 

are readily available worldwide. In the charged state, each cell of the lead-acid battery contains 

electrodes of lead metal (Pb) and lead (IV) oxide (PbO2) mixed with other materials in an 

electrolyte of sulfuric acid (H2SO4). In the discharged state, both electrodes turn into lead (II) 

sulfate (PbSO4) and the electrolyte loses its dissolved sulfuric acid and becomes primarily water. 

Separators are used between the positive and negative plates of a lead acid battery to prevent 

short circuit through physical contact. 
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The size of the battery bank required depends on storage capacity needed, the maximum 

discharge rate, the maximum charge rate, and the minimum temperature at which the batteries 

will be used. Temperature has a significant effect on lead-acid batteries. For example, at 40°F 

the rated capacity is 75% while the capacity drops to 50% at 0°F. The battery in a PV system 

should be designed to supply needed power during the longest expected period of cloudy weather 

and should be sized at least 20% larger than this amount to verify the system will continuously 

operate. 

While there are many different sizes and designs of lead-acid batteries, the most important 

designation is whether they are deep cycle or shallow cycle batteries. Shallow cycle batteries are 

designed to supply large amounts of current for a short time period and stand small amounts of 

overcharge without losing electrolyte. They can’t tolerate being discharged more than 20% 

without severely shortening the life of the battery. Therefore, shallow cycle lead-acid batteries 

are not a good choice for PV cells. Deep cycle batteries, however, are designed to be repeatedly 

discharged by as much as 80% of their capacity and are, therefore, a good choice for PV 

modules. All lead-acid batteries fail earlier if they are not recharged completely after each cycle. 

Deep cycle lead-acid batteries which are sealed are relatively maintenance free and never need 

watering or an equalization charge. While sealed batteries are more costly, the maintenance free 

quality makes them more suitable for a remote location such as Paradox. 

Batteries should be stored inside a building/trailer, with an approximate area of 2,000 sf. 

Operation Schedule of the System 

As long as there is power available to the brine disposal system, it will be operational. In order 

to maintain operation 24 hours a day, 6 MW of power would need to be produced during 

daylight hours: 3 MW to operate the system directly, and 3 MW for battery storage to operate the 

system overnight. The system would be operational for all clear or partly clear days. In the 

Paradox area, this is up to 240 days annually. Economics will dictate whether or not it is viable 

to oversize the solar system for 24-hour operation. 

Solar Gradient Pond 

A solar gradient pond (SGP) is proposed to be included in the ZLD system for final disposal of 

the crystals formed in the BC. SGP systems are further described in Alternative 14. 

Environmental Feasibility 

Most environmental issues relative to ZLD have been addressed for the current system. Namely, 

the environmental issues related to the system that extracts the brine and conveys it to a central 

location. It is assumed that the ZLD facilities will be constructed adjacent to the surface 

treatment facilities where BOR already owns property. The EA generated for the existing 

facility will need to be updated to reflect the ZLD system. Since the ZLD facility will utilize a 

relatively small area of previously disturbed land, updating the EA should not be very difficult 

Groundwater Quality. The ZLD process will produce crystallized salt. This salt will need to be 

stored on-site before being hauled to a landfill for disposal. Although the groundwater beneath 
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June 08 19 of 35 

the facility is the brine that is being extracted, an impervious pad will be required to prevent the 

salt from leaching back into the groundwater during precipitation events. 

Water Rights. ZLD will not impact any water rights beyond what is currently occurring. 

Surface Water. A major factor associated with ZLD is that there is no liquid discharge that could 

impact surface water. Storm water from the facility will need to be controlled to prevent 

sediment loading to the Dolores River. A salt handling system will also need to be developed to 

prevent stockpiled salt from leaving the site in runoff. 

Vegetation. Some black greasewood and seabite will be impacted by the ZLD facility. 

However, the impact will be minimal due to very limited vegetation. Soil in this area is very 

saline, which limits vegetation. 

Wetlands and Riparian Habitats. No wetlands or riparian areas should be impacted by this 

alternative. 

Fisheries. Impact on fisheries should not change from the current situation. 

Wildlife. Impact of the project on wildlife is limited to the disruption caused by human activity 

as a result of operating the unit on a long term basis. The small footprint of the ZLD facility will 

not impact access to the river by wildlife and will cause little if any reduction of habitat. 

Threatened and Endangered Species. No additional threatened and endangered species issues 

are expected as a result of this alternative. 

Cultural Resources: A cultural resources survey will need to be conducted prior to any 

construction. Any sites identified will need to be avoided or mitigated. 

Air Quality: Most of the extracted brine contains hydrogen sulfide. The hydrogen sulfide would 

be released to the atmosphere as a result of the ZLD process if the hydrogen sulfide is not 

removed from the brine prior to starting the ZLD process. Hydrogen sulfide is very toxic and 

highly corrosive. If the hydrogen sulfide is to be vented, some treatment will be required to 

eliminate the hazard. An air quality permit may be necessary if any hydrogen sulfide is to be 

released. Currently, hydrogen sulfide is being released and the state of Colorado is not 

regulating that release. A permit may be necessary in the future. A process that oxidizes the 

hydrogen sulfide, to produce a solid that can be disposed of with the salt, is included in this 

alternative. 

A ZLD facility appears to be environmentally feasible. 

Economic Feasibility 

The two main components to the cost of the crystallizer are the capital cost and the energy cost. 

A single 100 gpm BC unit costs approximately $6.7 million for equipment, supply and design, 

and $4.5 million for installation. Therefore, the total cost for one 100 gpm unit installed is about 
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$11.2 million. The cost to provide and install two 100 gpm units is approximately $22.4 million. 

As mentioned previously, the energy required to operate a crystallizer is approximately 250 

kWh/1,000 gal/hr. Therefore, a feed of 200 gpm would require 3000 kWh/hr (26,000 

MWhr/year) for treatment. Assuming an energy cost of $.06/kWh, the result is a cost of $180/hr 

to power the crystallizers. If operation of the crystallizers is 24 hours a day and 346 days a year 

(allowing for cleaning and maintenance), energy costs would be approximately $1.5 million 

annually. However, the existing power system at Paradox does not have sufficient excess 

capacity for the ZLD system. Even considering partial power supply from the existing system 

(600 kW) and a solar gradient pond (50 kW), an additional power source (2.4 MW) is needed for 

the ZLD system. This would be met by the solar complex. 

Solar Gradient Pond Cost 

Capital cost of the SGP is expected to be about $1 million (refer to Alternative 14), and annual 

operation and maintenance (O&M) costs are estimated at $50,000. 

Solar System Cost 

The cost associated with installing a 3 MW solar farm (including inverters) is approximately $19 

million. This cost can vary due to several factors, including site conditions such as soil 

composition, weather, and electrical interconnections required during installation. Since there is 

a 30 year design life on the panels and a 25 year power guarantee, module replacement cost is 

not a major factor. However, it is recommended that a few spares be purchased at time of 

construction in case panels break due to vandalism or lightening strikes. O&M costs are about 

0.5% annually of the capital cost. Therefore, it is expected that O&M costs for the solar complex 

would be $100,000/yr. This cost is to conduct a visual annual inspection of panels for any 

damage. It also includes the cost for an electrician to open all cabinets to check for debris and 

arching and inspect inverters and disconnects. If a dry weather period is experienced, water 

trucks may be needed to spray the panels once or twice a year. 

The capital cost associated with inverters is included in the initial capital cost of the solar 

complex. However, inverters have a shorter life cycle than the solar modules and need to be 

replaced every 12 to 15 years. The replacement cost for a 0.5 MW inverter is $160,000. 

Therefore, to replace the inverters for the 3 MW solar farm, the cost would be approximately 

$1.0 million. The O&M costs associated with inverters are included in the 0.5% O&M costs for 

solar panels. Inverters need to be visually checked once annually to verify they are continuing to 

provide the required power. 

The costs associated with batteries can vary depending on the type of battery chosen. An 

average value for turnkey battery storage is about $600,000/MWh. Therefore, assuming battery 

operation for 12 hours and 3 MW of storage needed, the capital cost associated with battery 

installation may approach $21 million. O&M costs for battery storage is also dependent upon 

the battery type chosen, but an average value is about $0.02/kWh. Using the same assumptions 

as with capital cost (12 hours of operation and 3 hours of storage), the annual O&M costs for 

battery operation are approximately $720/day. Based on weather data, there are approximately 

240 fair and clear days at the Paradox site annually. This means the solar panels and batteries 
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can be expected to run approximately 240 days annually. Therefore, the annual O&M cost for 

batteries at Paradox is expected to be about $200,000. 

Scenarios 

Four scenarios are considered in the economic feasibility of Alternative 4 (ZLD): 

1. Operation for 8 months/year during daylight hours. 

2. Operation for 8 months/year, 24 hours per day, with batteries providing night ZLD 

operations. 

3. Operation for 8 months/year, daylight hours with solar power; 4 months/year, 24 

hours/day with existing power supply excess capacity. 

4. Operation for 8 months/year, 24 hours per day with solar power and batteries; 4 

months/year, 24 hours per day with existing power supply excess capacity. 

Production Options 

Condition Option 

A B C D 

Operation Schedule 

• 8 months/year – Solar Power 

• 4 months/year – Existing Power Supply 

• • • 

• 

• 

• 

Daily Schedule 

• Daylight – 12 hours 

• Day & Night – 24 hours 

• 

• 

 •(a)

 •(b)

Salt Removal (tons/year) 35,000 70,000 41,000 76,000 

(a) 8 months/year – solar power 

(b) 4 months/year – existing supply, excess power 
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Cost Summary 

(a) Includes battery replacement at $1.4 million/year

Component 

Scenario 

A B C D 

Day 

Only 

24 Hours

Day 

12 Hours 

12 Months 

24 Hours

12 Months 

Capital Cost ($M) 

• ZLD 

• Solar Complex 

• Batteries (night power) 

• SGP 

• H2S Stripping Plant 

22.4 

14.5 

- 

1.0 

2.3 

22.4 

29.0 

18.0 

1.0 

2.3 

22.4 

14.5 

- 

1.0 

2.3 

22.4 

29.0 

18.0 

1.0 

2.3 

TOTAL 40.2 72.7 40.2 72.7 

Capital Recovery ($M/yr) (4.875%, 30 yrs) 

• ZLD 

• Solar Complex 

• Batteries 

• SGP 

• H2S Stripping Plant 

1.44 

0.93 

- 

0.064 

0.15 

1.44 

1.86 

1.15 

0.064 

0.15 

1.44 

0.93 

- 

0.064 

0.15 

1.44 

1.86 

1.15 

0.064 

0.15 

TOTAL 2.22 3.99 2.22 3.99 

O&M ($M/yr) 

• ZLD 

• Solar Complex 

• Batteries (existing power) 

• SGP 

• H2S Stripping Plant 

• Existing Extraction Wells 

0.05 

0.13 

- 

0.05 

0.02 

0.30 

0.10 

0.26 

1.60(a)

0.05 

0.02 

0.30 

0.05 

0.13 

0.30 

0.05 

0.02 

0.30 

0.10 

0.26 

1.90(a)

0.05 

0.02 

0.30 

TOTAL 0.55 2.33 0.85 2.63 

Annual Cost ($M/yr) 

• ZLD 

• Solar Complex 

• Batteries (existing power) 

• SGP 

• H2S Stripping Plant 

• Existing Extraction Wells 

• Salt Disposal 

1.49 

1.06 

- 

0.12 

0.17 

0.30 

0.70 

1.54 

2.12 

2.75 

0.12 

0.17 

0.30 

1.40 

1.49 

1.06 

0.30 

0.12 

0.17 

0.30 

0.82 

1.54 

2.12 

3.05 

0.12 

0.17 

0.30 

1.52 

TOTAL 3.84 8.4 4.26 8.82 

Salt Removal (tons/yr) 35,000 70,000 41,000 76,000 

Unit Cost ($/ton) 109.7 120.0 103.9 116.1 
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Alternative 5: Dewvaporation 

When developing a plan for the control of brine inflow to the Dolores River in the Paradox 

Valley, the BOR originally intended to use a large evaporation basin. Subsequently, BOR chose 

to inject the brine into the Mississippian formation. This alternative would replace the current 

injection well with a Dewvaporation brine concentrator/crystallizer2

, with the crystallized salt 

solids being disposed of in a permitted land fill located about 25 miles from the current 

collection well filtering facility, near Naturita, Colorado. 

The Dewvaporation system would be designed to manage the current operating brine volume of 

330 acre-feet per year (300,000 GPD) and an average salt disposal of 109,000 tons. Assuming 

that saturation and crystallization would occur with about 27-percent moisture, about 220,000 

GPD of liquid would need to be removed from the brine. 

Removal of this volume of liquid would require about two hundred twenty (220), 1,000 GPD 

Dewvaporation units as well as land fill for disposal of 109,000 cu. yards per year of salt. 

Environmental Feasibility 

Most environmental issues relative to Dewvaporation have been addressed for the current 

system. Namely, the environmental issues related to the system that extracts the brine and 

conveys it to a central location. It is assumed that the Dewvaporation facilities will be 

constructed adjacent to the surface treatment facilities where BOR already owns property. The 

EA generated for the existing facility will need to be updated to reflect the Dewvaporation 

system. Since the Dewvaporation facility will utilize a relatively small area of previously 

disturbed land, updating the EA should not be very difficult 

Groundwater Quality. The Dewvaporation facility will be sited in a location near the existing 

collection well filtering facility. In normal operations, the combined facilities would operate 

without any liquid discharge, and therefore there would not be any release of the brine to local 

surface water or ground water. Potential groundwater contamination concerns, with the existing 

conveyance pipeline and injection well, would be eliminated as those facilities would no longer 

operate. The Dewvaporation process will produce crystallized salt. This salt will need to be 

stored on-site before being hauled to a landfill for disposal. Although the groundwater beneath 

the facility is the brine that is being extracted, an impervious pad will be required to prevent the 

salt from leaching back into the groundwater during precipitation events. 

Water Rights. Dewvaporation will not impact any water rights beyond what is currently 

occurring. 

Surface Water. A major factor associated with Dewvaporation is that there is no liquid discharge 

that could impact surface water. Storm water from the facility will need to be controlled to 

 

2

 Mr. Mike Clinton, a contributor to this document, retains a business interest in the Dewvaporation technology, 

stemming from litigation and a settlement agreement approved by the Maricopa County Superior Court, Arizona. 
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prevent sediment loading to the Dolores River. A salt handling system will also need to be 

developed to prevent stockpiled salt from leaving the site in runoff. 

Vegetation. Some black greasewood and seabite will be impacted by the Dewvaporation facility. 

However, the impact will be minimal due to very limited vegetation. Soil in this area is very 

saline, which limits vegetation. 

Wetlands and Riparian Habitats. No wetlands or riparian areas should be impacted by this 

alternative. 

Fisheries. Impact on fisheries should not change from the current situation. 

Wildlife. Impact of the project on wildlife is limited to the disruption caused by human activity 

as a result of operating the unit on a long term basis. The small footprint of the Dewvaporation 

facility will not impact access to the river by wildlife and will cause little if any reduction of 

habitat. 

Threatened and Endangered Species. No additional threatened and endangered species issues 

are expected as a result of this alternative. 

Cultural Resources: A cultural resources survey will need to be conducted prior to any 

construction. Any sites identified will need to be avoided. 

Air Quality: Most of the extracted brine contains hydrogen sulfide. The hydrogen sulfide would 

be released to the atmosphere as a result of the Dewvaporation process if the hydrogen sulfide is 

not removed from the brine prior to starting the process. Hydrogen sulfide is very toxic and 

highly corrosive. If the hydrogen sulfide is to be vented, some treatment will be required to 

eliminate the hazard. An air quality permit may be necessary if hydrogen sulfide is to be 

released. A process that oxidizes the hydrogen sulfide to produce a solid that can be disposed of 

with the salt is recommended to prevent potential permitting issues and prevent corrosion of the 

equipment by the hydrogen sulfide. 

In addition to the above issues, all necessary permitting and mitigation efforts will need to be 

completed for decommissioning the current injection well and delivery pipeline. 

A Dewvaporation facility appears to be environmentally feasible. 

Economic Feasibility 

Based upon a Navajo Generation Station crystallizer proposal submitted to BOR in early 2004, 

such a system would have the following components: 

• Two-hundred and twenty 1,000 GPD Dewvaporation Units 

• One Hydrogen Sulfide Stripping Plant 

• One 7,700 square-foot process building 

• 0.4 acres of Right-of-way 

• Piping and equipment installation 
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• 191 million pounds of process steam per year 

• 433 MWHrs of electricity per year 

• 1.00 equivalent person years of O&M labor 

• Supplies and chemicals 

• Land fill for salt disposal (109,000 cu. yards per year). 

Based upon the 2004 NGS proposal, scaled up to 2008 costs, total capital costs for such a 

configuration (with contingencies and unlisted items) would be about $12 millon (2008 dollars). 

Annualized over 15 years at 4.875 percent interest, the annual debt service payment would be 

about $1,150,000. 

Annual O&M, power, steam, and salt disposal costs would be about $3.5 million (2008 dollars). 

These costs are incremental increases to the $300,000/yr. current O&M costs, for the collection 

wells and filtration facility. Therefore, the annual O&M cost for this alternative would be about 

$3.8 million/year. 

The Dewvaporation Alternative would allow the collection and removal of 109,000 tons per year 

that now enter the Dolores River at an annual cost of $5 million per year and an incremental cost 

of about $45.84 per ton. 

Alternative 6: Other Innovative Treatments 

This alternative had been originally divided into four options. Of the four options originally 

proposed, only Vibratory Shear Enhanced Process (VSEP) has been carried forward from the 

technical feasibility phase. 

Alternative 6B: Vibratory Shear Enhanced Process (VSEP) 

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

VSEP concentrates the brine by extracting fresh water. 

Environmental Feasibility 

Many environmental issues relative to VSEP have been addressed for the current system. 

Namely, the environmental issues related to the system that extracts the brine and conveys it to a 

central location. However, VSEP can only concentrate the brine, not dispose of it. Hence 

another method of actual disposal will be necessary such as an evaporation basin, ZLD, or 

Dewvaporation. This section will only address the environmental issues specific to VSEP. 

The following are two major environmental constraints associated with VSEP: 

• Very high energy use caused by the extensive power that would be required to produce 

high feed pressures to overcome the osmotic pressures, related to the near-saturation salt 

levels in the Paradox brine; and 
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• Very high use of acid and caustic chemicals that would be needed for expected constant 

process plant cleanings. 

Quantitative estimates of these impacts cannot be made without further research and bench/pilot 

testing of the VSEP process. However, the following environmental impacts can be expected. 

Groundwater Quality. The VSEP process will produce a concentrated brine. This concentrated 

brine has the potential to degrade groundwater quality further if released. The concentrated brine 

will need to be handled to prevent any release to the groundwater. 

Water Rights. VSEP will not impact any water rights beyond what is currently occurring other 

than increasing the fresh water in the Dolores River if it is discharged to the river. Due to the 

quality of the water, BOR may be able to sell the water as culinary water to residents in the 

Paradox Valley. 

Surface Water. Surface water resources would need to be protected from the concentrated brine. 

If fresh water from the system is discharged to the river, a discharge permit will be needed. The 

discharge permit should be easy to obtain due to the quality of the water being discharged. 

Vegetation. Some black greasewood and seabite will be impacted by the VSEP facility. 

However, the impact will be minimal due to very limited vegetation. Soil in this area is very 

saline, which limits vegetation. 

Wetlands and Riparian Habitats. No wetlands or riparian areas should be impacted by this 

alternative. 

Fisheries. Impact on fisheries should not change from the current situation other than a 

possibility of improving water quality by discharging very clean water. 

Wildlife. Impact of the project on wildlife is limited to the disruption caused by human activity 

as a result of operating the unit on a long term basis. The small footprint of the VSEP facility 

will not impact access to the river by wildlife and will cause little if any reduction of habitat. 

Threatened and Endangered Species. No additional threatened and endangered species issues 

are expect as a result of this alternative. 

Cultural Resources: A cultural resources survey will need to be conducted prior to any 

construction. Any sites identified will need to be avoided. 

Air Quality: Most of the extracted brine contains hydrogen sulfide. The VSEP process may not 

prevent the hydrogen sulfide from getting into the fresh water. Hydrogen sulfide in the fresh 

water would make it unusable. Hydrogen sulfide may also damage the VSEP unit. A hydrogen 

sulfide stripping unit should be included as part of any VSEP unit. If the hydrogen sulfide is to 

be vented, some treatment will be required to eliminate the hazard. An air quality permit will be 

necessary if any hydrogen sulfide is to be released. Due to the toxicity of hydrogen sulfide 
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permitting of any releases will be difficult if not impossible. A process that oxidizes the 

hydrogen sulfide to produce a solid that can be disposed of with the salt is recommended. 

A VSEP facility appears to be an environmentally feasible component to a brine treatment 

system. 

Economic Feasibility 

The extremely high TDS levels in the Paradox brine would require the following VSEP process 

provisions: 

• Multiple RO/NF membrane trains, with resultant significant cost increase; 

• Very high feed pressures and feed pump/electrical equipment cost increases; 

• Special provisions and costs for expected constant membrane cleaning; 

• Extensive cleaning chemical deliveries, storage, and dosing; 

• Major risk of membrane scaling, notwithstanding the extensive cleaning regimen. 

Quantitative estimates of these costs are not possible without bench/pilot testing, which could be 

undertaken if VSEP is required in a multiple – project program. 

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 a smaller version of the Radium Site 

proposed in the 1979 DPR and evaporation basins in East Paradox Valley. 

Environmental Feasibility 

The environmental issues related to evaporation basins at the Radium Site or in the East Paradox 

Valley are the same. The environmental feasibility analysis is presented here for both options 

while the economic feasibility analysis for the options will be presented separately. The EA 

prepared for the current system will require fairly substantial additions to address the issues 

associated with the evaporation basins. The larger effort required is due to the large area 

impacted by construction of an evaporation basin and the fact that it will also be used as a 

landfill for the salt. Although the environmental issues associated with both sites are similar, it 

should be noted that the EPA has already expressed strong opposition to the Radium Site. 

Groundwater Quality. The Colorado State Department of Health and Environment, Solid and 

hazardous Waste was contacted to identify the environmental issues related to an evaporation 

basin. The salt in the evaporation is not considered a hazardous waste but the state will still 

require a double liner for the evaporation basins. The double liner may be 2 feet of clay 

(secondary) plus a synthetic liner (primary). It may also be two synthetic liners. The ponds will 

also need a groundwater monitoring system. A permit from the state of Colorado will be needed 

before any construction activities can take place. 
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Water Rights. The use of evaporation basins will not impact water rights. 

Surface Water. The evaporation basins would be designed such that runoff will be diverted away 

from the evaporation basins and discharge from the basins will not occur. 

Vegetation. A large area will be disturbed to build the evaporation basins. The vegetation 

impacted will likely be black greasewood, seabite, pinyon juniper, sage brush, cacti, yucca, salt 

brush, and some grasses. Some mitigation may be required if the area is shown to be critical 

habitat. 

Wetlands and Riparian Habitats. No wetlands or riparian areas should be impacted by this 

alternative. 

Fisheries. Impact on fisheries should not change from the current situation. 

Wildlife. Impact of the project on wildlife is expected to be greatest on migrating birds. The 

FWS may require that all birds be prevented from use of the evaporation basins by using nets or 

a noise making device. There is some conflict on this issue. The draft EIS for the Radium pond 

referenced a Colorado State University study that indicated the concentrated brine would not be a 

concern for migrating birds. It should also be noted that the evaporation ponds around the Great 

Salt Lake are used extensively by birds with apparently no negative impacts. However, for this 

discussion it is assumed that birds may need to be prevented from using the evaporation basins. 

The basins will also remove some habitat for upland species. This loss of habitat may require 

mitigation. 

Threatened and Endangered Species. There is some potential that an endangered species’ 

habitat will be impacted by the evaporation basins. Such impacts, if they occur, will likely 

require some mitigation. The assessment of the impacts and any mitigation would be part of the 

NEPA process. 

Cultural Resources: A cultural resources survey will need to be conducted prior to any 

construction. Any sites identified will need to be avoided. 

Air Quality: Most of the extracted brine contains hydrogen sulfide. Due to the very toxic and 

corrosive nature of hydrogen sulfide, the brine cannot be discharged to the evaporation basin 

until the hydrogen sulfide has been stripped from the brine. A hydrogen sulfide stripping unit 

should be included as part of any evaporation basin plan. A process that oxidizes the hydrogen 

sulfide to produce a solid that can be disposed of with the salt is recommended. 

EPA has expressed in the past a concern about wind blown salt. When salt precipitates out, it 

crystallizes and becomes a rock-hard mass. Two examples of this were observed by the BOR 

while preparing the 1978 Definite Plan Report, one on the Malaga Bend Experimental Salinity 

Alleviation Project in New Mexico and the other at Texas Gulf Sulfur at Moab, Utah. Both have 

a large pond with large amounts of precipitated salts around the edges. Vegetation around the 

two areas showed no sign that any salt had blown from the pond. The prevailing winds in the 

area, as measured at BOR stations at Bedrock are from the southwest. Any minor quantities of 
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windblown salt would be carried to the northeast and in the direction of the alkaline/salinetolerant vegetation. Records show the winds are at their most forceful in spring when the ground 

is dampest, further reducing the possibility of an airborne dust problem. 

The only noxious odors associated with the brine stem from hydrogen sulfide gas, which would 

be stripped from the brine before it reaches the evaporation pond. There would be no odors from 

bacteriological factors at the evaporation pond itself; because of severe osmotic pressure 

associated with brine, the pond would be essentially lifeless. Salt is not considered to be any 

worse than wind borne dust, but the dust issue will likely need to be addressed in an air quality 

permit application. 

In addition to the above issues, all necessary permitting and mitigation efforts will need to be 

completed for decommissioning the current injection well and delivery pipeline. 

An evaporation basin appears to be an environmentally feasible treatment option. However, the 

environmental issues to be addressed are more complex than for some of the other alternatives 

identified. 

Economic Feasibility 

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, was designed to hold 93,340 acre-feet with nearly 

26,000 acre-feet allocated for flood control and surcharge capacity, and was assumed that about 

5 cfs of brine would need to be evaporated. 

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

gallons per year or 310 acre-feet per year (0.43 cfs). 

Under this Alternative 9(A), the Radium Reservoir facility would be further downsized to reflect 

the smaller volume of brine now being collected. 

Based upon the scaled up 1997 cost estimates contained in the Supplemental DPR and indexed to 

2008 costs, total capital costs for such a configuration (with contingencies and unlisted items and 

without waterfowl netting) would be about $103 million (2008 dollars). Annualized over 100 

years at 4.785 percent interest, the annual debt service payment would be about $5.06 million per 

year. 

Annual O&M costs would be about $3.6 million per year (2008 dollars). 

The debt service and annual O&M costs of $8.66 million (2008 dollars), when compared to a 

total salt removal of 109,000 tons per year suggests a removal cost of $79.45 per ton. 
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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, 330 acres of evaporation surface area 

would need to be in operation to provide for evaporation of the 330 acre-feet per year of 

collected brine. 

At the current 109,000 tons per year collection rate, assuming 9 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 (about 8 feet 

of depth in a 330 acre evaporation basin). Only one or two ponds would need to be constructed 

over the 100 year project planning period. When filled with salt, an evaporation basin would be 

decommissioned by sealing the top and mounding the site in a manner to assure that precipitation 

runs off, thus preventing moisture infiltration. 

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

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 was 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 basin. 

For cost estimating purposes, we have assumed that the initial construction would involve 

development of one 330 acre pond with an average depth of 10 feet (3,300 acre-feet of storage 

capacity, which would be 80 percent filled with solids in a 100 year period). Based upon recent 

experience at the Palo Verde Nuclear Generating Station near Phoenix, double Butyl rubber lined 

evaporation ponds are costing from $250,000 to $450,000 per acre (2006 dollars). Since there is 

no recoverable groundwater under the East Paradox Valley, a lesser sophisticated lining 

approach may be acceptable. At the lower range of costs, 330 acres of evaporation ponds would 

have a capital cost of about $125 million (2006 dollars).

It is assumed that a Hydrogen Sulfide stripping plant could be located adjacent to current 

filtration equipment and would have a capital cost of about $4 million. 

Because of the conflict over migratory bird exclusion from evaporation ponds, costs have been 

calculated below for ponds without and with waterfowl netting. 

Without Waterfowl Netting -- Capital costs for the evaporation pond and Hydrogen Sulfide 

removal facility (with contingencies and unlisted items) would be about $129 million (2008 

dollars). With the evaporation pond cost annualized over 100 years and the hydrogen sulfide 

removal facility annualized over 30 years at 4.875 percent interest, the annual debt service 

payment would be about $6.4 million per year. 
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Annual O&M costs would be about $75,000 (2008 dollars). 

The debt service and annual O&M costs of $7.15 million per year (2008 dollars), when 

compared to a total salt removal of 109,000 tons per year, suggests a removal cost of $65.60 per 

ton. 

With Waterfowl Netting -- Capital costs for the possibly needed waterfowl netting (with 

contingencies and unlisted items) would be about $93 million (2008 dollars). Annualized over 

15 years at 4.875 percent interest, the annual debt service payment would be about $8.9 million 

per year. Adding these incremental costs to those above, would result in a total capital cost of 

$220 million and an annual debt service of about $15.35 million per year. 

Annual O&M costs would be about $75,000 (2008 dollars). 

The debt service and annual O&M costs of $15.1 million per year (2008 dollars), when 

compared to a total salt removal of 109,000 tons per year, suggests a removal cost of $147.71 per 

ton. 

Alternative 11: Agricultural Land Management 

Description of Alternative 

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

irrigated farmlands (1100 acres) nearest to the Dolores River would be leased and used for 

wildlife habitat purposes. It is estimated that deep percolation from these farmlands amounts to 

about 0.5 acre-feet per acre, or 550 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 77 acrefeet per year. 

Environmental Feasibility 

Environmental issues associated with this alternative are very limited since it involves taking 

private land and using it for wildlife habitat. However, since this is a federal project there will 

need to be NEPA compliance. The NEPA compliance for this alternative is expected to be fairly 

easy. 

This alternative is environmentally feasible. 

Economic Feasibility 

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

payments of about $65 per acre, resulting in an annual cost of about $71,500 per year. The 

USDA Conservation Reserve Program is currently paying $65/acre for highly productive land in 

the Grand Valley. It is expected that the rate in the Paradox Valley will be less. However, to be 
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conservative, a rate of $65/acre is assumed for this alternative. With a reduction of 77 acre-feet 

per year of 250,000 mg/l brine reduction, the associated salt load reduction would be about 

26,800 tons per year, with a resulting cost-effectiveness of about $2.67 per ton. 

Alternative 14: Integrated Evaporation Pond and Treatment 

Approaches 

Overall Concept. Under this alternative, overall collection well pumping would be increased to 

465 acre-feet/year to increase the salt removal by 50 percent and eliminate the current salt 

loading to the Dolores River. Also, the fluid being pumped into the injection well would be 

concentrated to 300,000 mg/l. About 72 acre-feet/year of fluid from the higher salinity (260,000 

mg/l) collection wells would be filtered and delivered to the injection well. An additional 393 

acre-feet/year of collection well pumping would be stripped of hydrogen sulfide and delivered to 

a 2.5-acre solar gradient pond (SGP) having a depth of 15 feet. The SGP would evaporate about 

2.5 acre-feet/year of brine and provide the heat energy needed to concentrate and dispose of the 

remaining brine. About 238 acre-feet/year of 312,000 mg/l reject from the brine concentrator 

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

blend (310 acre-feet/year of 300,000 mg/l brine) containing about 126,000 tons per year would 

be delivered to the existing well for injection. 

Operation of the Solar Gradient Pond. Of the 393 acre-feet/year of collected brine delivered to 

the SGP, two acre-feet would evaporate, 238 acre-feet/year would be returned to the injection 

well, and the remaining 153 acre-feet/year would be concentrated to a near solid state. 

Assuming that saturation and crystallization would occur with about 27-percent moisture, about 

120 acre-feet/year or about 107,000 GPD of liquid would need to be removed from the brine. 

Removal of this volume of liquid would require about eleven 10,000 GPD Dewvaporation Units. 

Operation of the Brine Concentrator. The 2.5 acre solar gradient pond could produce about 250 

GPM of 185oF brine. Total flow to the eleven Dewvaporation Units would be 242 GPM of 

which one-third would evaporate and two-thirds would become reject water, which would be 

returned to the solar gradient pond at about 100o. Although it may be possible to recapture 120 

acre-feet/year of 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. 

Environmental Feasibility 

The feature unique to this alternative is the solar gradient pond. The environmental issues 

relative to a Dewvaporation unit have been discussed previously. The solar gradient pond is 

similar to the evaporation basins with the exception that the pond will be much smaller and in a 

different location. The solar gradient pond will be approximately 2 acres in size. The pond will 

be in the current extraction area, possibly where evaporation ponds were formerly located. 

Groundwater Quality. The Colorado State Department of Health and Environment, Solid and 

hazardous Waste was contacted to identify the environmental issues related to a solar gradient 
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pond. The brine/salt in the pond is not considered a hazardous waste but the state will still 

require a double liner. The double liner may be 2 feet of clay (secondary) plus a synthetic liner 

(primary). It may also be two synthetic liners. The ponds will also need a groundwater 

monitoring system. A permit from the state of Colorado will be needed before any construction 

activities can take place. 

Water Rights. The use of evaporation basins will not impact water rights. 

Surface Water. The pond would be designed such that runoff will be diverted away from the 

ponds and discharge from the basins will not occur. 

Vegetation. A relatively small area will be disturbed to build the ponds. It is likely that the area 

has already been disturbed. The vegetation impacted will likely be black greasewood and seabite 

which is poor habitat. However, some mitigation may be required if the area is shown to be 

critical habitat for an endangered species. 

Wetlands and Riparian Habitats. No wetlands or riparian areas should be impacted by this 

alternative. 

Fisheries. Impact on fisheries should not change from the current situation. 

Wildlife. Impact of the project on wildlife is expected to be greatest on migrating birds. The 

FWS may require that all birds be prevented from use of the evaporation basins using nets or a 

noise making device. Cost estimates do not include netting to prevent bird use of the solar 

gradient ponds. 

Threatened and Endangered Species. There is little potential that an endangered species’ habitat 

will be impacted by the pond. However, mitigation will be required if the ponds impacts and 

endangered species. The assessment of the impacts and any mitigation would be part of the 

NEPA process. 

Cultural Resources: A cultural resources survey will need to be conducted prior to any 

construction. Any sites identified will need to be avoided. 

Air Quality: Most of the extracted brine contains hydrogen sulfide. Due to the very toxic and 

corrosive nature of hydrogen sulfide, the brine cannot be discharged to the pond until the 

hydrogen sulfide has been stripped from the brine. A hydrogen sulfide stripping unit should be 

included as part of any pond. A process that oxidizes the hydrogen sulfide to produce a solid 

that can be disposed of with the salt is recommended. 

A solar gradient pond appears to be an environmentally feasible when included with other 

treatment alternatives. 
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Economic Feasibility 

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

2004, such a system would have the following components: 

• Two and one-half acre Solar Gradient Pond with Piping 

• One-hundred ten 1,000 GPD Dewvaporation Units 

• One Hydrogen Sulfide Stripping Plant 

• One 3,850 square foot process building 

• 3 acres of Right-of-way 

• Piping and equipment installation 

• 217 MWHrs of electricity per year 

• 0.6 equivalent person years of O&M labor 

• Supplies and Chemicals 

• Land fill for 37,500 tons per year of salt disposal. 

Based upon the scaled-up 2004 NGS proposal, total capital costs for such a configuration (with 

contingencies and unlisted items) would be about $12.9 million (2008 dollars). Annualized over 

15 years at 4.875 percent interest, the annual debt service payment would be about $1.23 million 

per year. 

Annual O&M costs would be about $1.1 million (2008 dollars). 

These annual debt service and O&M costs are incremental increases to the $2.9 million current 

O&M costs and $8.462 million debt service for the collection wells, filtration facility, and 

injection well. Therefore, the annual debt service and O&M cost for this alternative would be 

about $13.7 million/year. 

The Integrated Evaporation Pond and Treatment Alternative would allow the collection and 

removal of 159,000 tons per year that now enter the Dolores River at an annual cost of about 

$85.90 per ton. 

Summary of Findings 

Table 1, below, summarizes the relative technical, environmental, and economic merit of the 

alternatives considered in this phase of the investigations. The Final Report will summarize all 

prior work and include recommendations on needed measures to address technical uncertainty 

and other future actions. 
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Table 1 

Summary of Results

Alternative 

No. Alternative Name 

Relative 

Technical 

Merit 

Environmental 

Feasibility 

Capital 

Cost 

($ Millions) 

Tons of Salt 

Removed 

per Year 

Expected 

Relative Cost 

Effectiveness 

($/Ton) 

1 Existing Collection and 

Injection System Good Excellent 66.3 109,000 66 

2A Replacement Injection 

Well Only Good Excellent 84.4 109,000 76 

2B 

Additional Injection Well 

operated with Current 

Well 

Good Excellent 84.4 109,000 68 

3(A) Divert Lower West 

Paradox Creek Good Poor 1.3 4,000 19 

3(B) West Paradox 

Pressurized Irrigation Good Excellent 6.0 48,700 7 

3(C) Divert West Paradox 

Creek 

Excellent Poor 14.0 8,000 94 

3(D) 

Divert West Paradox 

Creek with Pressurized 

Irrigation 

Excellent Poor 18.0 56,700 17 

4A ZLD – 8 months only 

during daylight Good Excellent 40.2 35,000 110 

4B ZLD – 8 months, 24 hrs 

per day Good Excellent 72.7 70,000 120 

4C ZLD – 8 mo. Daylight 

only, 4 mo. 24 hrs/day Good Excellent 40.2 41,000 104 

4D ZLD 12 mo, 24 hrs/day Good Excellent 72.7 76,000 116 

5 Dewvaporation Unproven Excellent 12.0 109,000 46 

6(B) 

Vibratory Shear 

Enhanced Process 

(VSEP) 

Questiona

ble Good unknown 109,000 unknown 

9(A) 

Conventional 

Evaporation Basin – 

Radium Site 

Good Fair 103.0 109,000 79 

9(B1) 

Conventional 

Evaporation Basin – 

East Paradox Valley 

Without Nets 

Good Fair 129.0 109,000 66 

9(B2) 

Conventional 

Evaporation Basin – 

East Paradox Valley 

With Nets 

Good Good 220.0 109,000 148 

11 Agricultural Land 

Management Good Good $71,500/yr. 26,800 3 

14 

Integrated Evaporation 

Pond and Treatment 

Approaches 

Fair Good 12.9 159,000 86