The Seminole Project: Renewable Energy for Municipal Water ...

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Universities Council on Water Resources

Journal of Contemporary Water Research & Education Issue 151, Pages 50-60, August 2013

The Seminole Project: Renewable Energy for Municipal Water Desalination Ken Rainwater, Phil Nash, Lianfa Song, and John Schroeder Texas Tech University, Lubbock, TX

Abstract: This demonstration project addresses the continuing depletion of the Ogallala aquifer, the current principal source of potable ground water for much of the Texas High Plains. The project site is Seminole, Gaines County, Texas. Brackish ground water from the much deeper Santa Rosa aquifer in the Dockum group is produced and treated by reverse osmosis (RO) for potential use in the city’s municipal supply. The electrical power for the well pump and RO system is assisted by a 50-kW wind turbine. Financial support was from the City of Seminole, Department of Energy, Texas Water Development Board, Bureau of Reclamation, Texas Department of Agriculture, and State Energy Conservation Office. The Santa Rosa well and wind turbine were installed in 2011, and the RO system, turbine, well, and related infrastructure were ready for continuous operation in early 2013. A one-year demonstration will follow to document the seasonal electricity contributions from wind and grid sources. Keywords: Brackish ground water, desalination, renewable energy, wind turbine

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his paper describes the implementation of a field-scale demonstration project in which renewable wind energy assists in power supply for a brackish ground water well and reverse osmosis (RO) system to produce potable drinking water. Innovative combinations of proven technologies are needed to provide affordable water in many rural and small communities in the southwestern United States. This project also demonstrates the positive interactions of multiple agencies that encourage technology advances to promote the future stability of rural communities. Municipalities in the Texas High Plains face ongoing challenges as they plan for long-term water supplies for their citizens. All of these municipalities depend on the relatively shallow and typically fresh Ogallala aquifer for all or part of their potable water. The recent extended drought has greatly diminished surface water supplies in Lake Meredith, White River Lake, and Lake Mackenzie, which held 0.0, 4.2, and 6.5 percent of their capacities as of February 2013 (TWDB 2013). These three lakes normally contributed to the water supplies of 19 cities, increasing their current ground water needs. In addition, longterm irrigation withdrawals in excess of recharge UCOWR

in the Texas High Plans have led to steady depletion of the Ogallala aquifer. Based on local water level declines observed from 1990 to 2004, researchers at the Texas Tech University Center for Geospatial Technology applied geographic information system tools to estimate and map the time until the local saturated thicknesses get too thin (< 30 ft) to allow sufficient pumping rates to supply center pivot systems (Center for Geospatial Technology 2006). For much of the Southern High Plains of Texas, south of Amarillo, only 30 to 50 years remain after 2004 for traditional irrigated agriculture, and municipalities may have to expand or relocate their well fields. More recently, many public water supply systems in the Texas High Plans have been reminded by the Environmental Protection Agency (EPA) and the Texas Commission for Environmental Quality that their ground waterbased supplies are out of compliance with federal standards. Typically, Ogallala ground water has received only disinfection prior to distribution, although homeowners could always consider additional point-of-use treatment. In the Southern High Plans, many local well fields are impacted by fluoride, arsenic, total dissolved solids (TDS), Journal of Contemporary Water Research & Education

Renewable Energy for Municipal Water Desalination and other primary or secondary drinking water maximum contaminant levels (MCLs). In a project funded by the U.S. Bureau of Reclamation, we collected information on 40 cities from the Texas Commission for Environmental Quality and the New Mexico Environment Department files to see if any had exceedances in at least their worst water supply well (Swift et al. 2009). The findings are provided in Table 1, which also includes the reported population and average daily demand, Qavg, in MGD. Exceedances of both primary and secondary MCLs were noted. Most of these communities used Ogallala water, but some used other local shallow aquifers. Overall, 39 of the 40 cities had one or more exceedances, and Table 2 breaks down the exceedances by parameter. These results indicated that, even with their existing ground water supplies, these municipalities are likely to require more involved treatment processes beyond disinfection or blending with less impacted well water to reduce the target constituents below the MCLs. Added treatment capability will require new infrastructure and operation and maintenance costs, including electricity. As these issues of decreasing freshwater supply and water quality compliance were being noted, the Texas Water Development Board started the Brackish Ground water Desalination Initiative in 2004 to facilitate use of brackish ground water across the state, such as the Dockum or Santa Rosa aquifer beneath the Ogallala in the Texas High Plans (Arroyo 2011). The Texas Water Development Board ’s Innovative Water Technologies program carries out that mission, and its interests often are in cooperation with the U.S. Bureau of Reclamation’s Desalination and Water Purification Program, which was originally authorized by the Water Desalination Act of 1996. In 2005, researchers from the Texas Tech Wind Science and Engineering (WiSE) Center and Water Resources Center began to explore the potential for connecting locally-owned renewable wind energy systems with the electrical needs for pumping and treating brackish ground water. It is well known that electricity can be 30 to 50 percent of the total cost of RO treatment, and renewable wind energy is readily accessible in the Texas High Plans, so the WiSE and Water Resources Center researchers began to investigate the potential for combining locally owned community wind systems with

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rural municipalities’ water production, treatment, and distribution infrastructure requirements. The intent was for behind-the-meter application of the renewable energy to reduce the community’s grid electricity needs when the wind is sufficient, with the possibility of shifting a significant portion of the electrical needs associated with drinking water delivery to that same time window, essentially storing lower cost energy in the produced water (Swift et al. 2009). Figure 1 provides a conceptual sketch of the addition of a brackish water production and treatment system to an existing municipal water system. It should be noted that concentrate management is another significant issue with any RO or desalination system, especially at inland sites that cannot just discharge to the ocean. Through public outreach workshops, the research team was approached by Mayor Mike Carter and other officials of Seminole, Texas, a town of about 6,300 residents with a declining Ogallala well field impacted by arsenic and fluoride. Seminole is the county seat of Gaines County, which is known for its irrigated and dryland agriculture as well as oil and gas production, so the city officials were comfortable with the possibility of drilling deeper wells into the Dockum group to tap the water in the interbedded sandstones and gravels, known to some locally as the Santa Rosa aquifer. The depth to the producing zone(s), water quality, and potential well flow rates were not well known locally, but recent expansions of wind turbine installations in the region were encouraging. The WiSE and Water Resources Center research team agreed to work with the City to develop and deploy a field-scale demonstration project, and reporting those efforts is the primary purpose of this manuscript. The project objectives included obtaining funding from various agencies and grants, planning and installation of a new well in the Dockum aquifer, selection and installation of an appropriate RO system, selection and installation of a 50 kW wind turbine, design and construction of other site infrastructure, and initiating appropriate operations to collect and report useful data from the demonstration project. As of the date of this manuscript, the demonstration project has been completely constructed, and official continuous operation of the system began in June 2013 for a period of 12 months. Later documents will provide the results from the demonstration period.

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Rainwater, Nash, Song, and Schroeder

Table 1. Communities with EPA Primary (bold italics) and Secondary (bold) MCL Exceedances (worst well reported). Qavg MGD

TDS mg/L 500

As mg/L 0.01

Cl mg/L 250

F mg/L 4, 2

SO4 mg/L 250

14400

2.750

1150

0.003

210

4.2

209

5.5

0.05

18.7

12866

1.448

714

0.008

87

4.4

202

2.6

0.12

13.5

City

County

Pop.

Hereford

Deaf Smith

Levelland

Hockley

NO3 Fe mg/L mg/L 10 0.3

Gross α pCi/L 15

Lamesa

Dawson

9942

1.570

1150

0.018

315

2.2

327

5.3

0.00

7.2

Andrews

Andrews

9652

2.388

660

0.038

157

4.4

116

2.2

0.00

3.4

Seminole

Gaines

5910

1.847

531

0.017

116

4.1

99

3.4

0.15

5.4

Tulia

Swisher

5200

0.795

2020

0.003

389

5.3

436

0.4

0.13

7.1

Denver City

Yoakum

3985

0.852

948

0.014

316

2.3

169

2.6

0.00

4.5

Crane

Crane

3191

1.053

464

0.013

59

1.5

147

2.2

0.00

4.8

Tahoka

Lynn

2910

0.405

1020

0.003

321

1.0

225

1.0

0.01

4.8

Stanton

Martin

2900

0.329

1111

0.020

302

2.4

425

10.1

0.00

2.0

Wolfforth

Lubbock

2710

0.442

652

0.015

76

5.8

131

2.2

0.00

10.7

Seagraves

Gaines

2334

0.328

788

0.049

120

4.7

223

10.9

0.00

6.7

Shallowater

Lubbock

2300

0.380

725

0.012

67

2.9

177

7.6

0.09

47.3

Morton

Cochran

2245

0.379

1050

0.015

217

3.6

342

5.1

1.00

6.4

Lorenzo

Crosby

1372

0.172

351

0.016

24

2.5

32

1.5

0.00

9.8

Plains

Yoakum

1350

0.931

1124

0.015

184

4.3

446

3.2

0.01

6.3

Booker

Lipscomb

1200

0.282

785

0.005

239

1.4

105

2.6

0.21

9.6

O’Donnell

Lynn

1011

0.100

1262

0.003

352

1.0

348

0.0

0.00

na

Silverton

Briscoe

780

0.111

358

0.012

19

3.5

19

1.1

0.02

na

Meadow

Terry

750

0.110

930

0.028

164

4.8

274

6.8

0.01

17.9

Lefors

Gray

560

0.093

3666

0.010

1926

0.2

4

1.5

0.07

0.0

Vaughn

Guadalupe

540

0.198

na

0.009

na

3.2

na

na

na

50.1

Wilson

Lynn

532

0.045

1336

0.009

275

4.0

350

11.0

0.00

16.9

Turkey

Hall

500

0.065

1237

0.005

157

1.5

437

17.1

0.01

10.8

Smyer

Hockley

480

0.053

1000

0.012

92

5.2

176

3.0

0.01

23.6

0.004

231

1.9

286

14.6

0.01

na

0.006

83

1.9

169

1.3

0.02

6.7

Quitaque

Briscoe

463

0.105

1124

Wickett

Ward

455

0.118

586

New Home

Lynn

440

0.047

859

0.026

135

5.0

171

5.0

0.00

10.0

Texhoma

Sherman

371

0.100

330

0.004

12

2.0

72

2.1

0.01

13.8

Welch

Dawson

354

0.049

1295

0.027

298

4.6

408

17.2

4.08

14.6

Floyd

Roosevelt

350

na

657

0.012

135

4.2

290

4.5

0.00

na

Loop

Gaines

300

0.031

654

0.031

27

4.9

197

7.0

0.00

na

Goldsmith

Ector

250

0.079

494

0.017

72

3.2

83

2.6

0.03

na

Wellman

Terry

225

0.038

823

0.037

108

5.7

241

5.3

0.01

8.8

Elida

Roosevelt

189

0.022

897

0.012

na

2.3

na

na

na

na

Opdyke West

Hockley

180

0.050

628

0.014

53

5.9

127

6.7

0.11

8.1

Whitharral

Hockley

175

0.054

1040

0.007

107

4.4

395

11.0

0.16

17.0

Dodson

Collingsworth

120

0.030

335

0.002

9

0.7

40

13.8

0.02

2.9

Grassland

Lynn

75

na

1732

0.020

659

5.0

332

13.0

0.00

16.6

Flomot

Motley

40

na

749

0.007

131

2.0

168

19.0

0.00

4.6

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Figure 1. Integrated wind-RO layout for an inland municipality (Swift et al. 2009). Table 2. Summary of Municipal Supply Exceedances. Parameter TDS Fluoride Arsenic Sulfate

Number of Cities 33 29 24 14

Parameter Chloride Nitrate Gross α Iron

Number of Cities 10 10 8 2

Funding Sources As with many demonstration projects, it is often necessary to leverage multiple sources of funds, and municipalities in Texas have access to some federal pass-through funds and state funds through different state agencies. The City of Seminole is mentioned first, as their local funds, managed by City Administrator Tommy Phillips, purchased the project site and provided the electrical connection to the grid. The City will retain the infrastructure at the site and be responsible for its day-to-day operation.


The Renewable Energy Demonstration Pilot Program in the Texas Department of Agriculture provided a large portion of the project funding as Seminole’s demographic characteristics qualified for low- and moderate-income incentives. The Texas Water Development Bureau provided most of the funds for the Dockum well, with the balance coming from the Texas Department of Agriculture grant and the Llano Estacado Underground Water Conservation District (LEUWCD). The State Energy Conservation Office (SECO) within the office of the Texas Comptroller provided part of the funds for the wind turbine purchase that was combined with Texas Department of Agriculture funds. The WiSE and Water Resources Center contributed funds from a multi-year Department of Energy project that were primarily used for geologic and engineering consultant services, the RO system, and engineering and project management services. A grant consulting firm, AJ Howco Services, provided overall coordination for contractual and financial requirements.

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Brackish Ground Water Well At the inception of the project in 2005, the primary reference describing the Dockum aquifer was by Bradley and Kalaswad (2003), who had collected all the previous reports and data held by the Texas Water Development Bureau and others. Later, Ewing et al. (2008) built on the work of Bradley and Kalaswad (2003) and others during development of a ground water availability model

intended to simulate hydraulic conditions within the aquifer. Figure 2 (Ewing et al. 2008) shows the extent of the Dockum aquifer in Texas and nearby New Mexico and Oklahoma, as well as estimated contours of TDS. The plus and circle symbols identify the locations of wells with available data for major ion water quality. It is clear that most of the available wells existed in the zones with lower TDS values, making large areas of the contour map uncertain. Of course, when the fresher

Figure 2. Extent and total dissolved solids (TDS) contour map of the Dockum aquifer (Ewing et al. 2008). UCOWR


Renewable Energy for Municipal Water Desalination Ogallala aquifer, which overlies the Dockum, was available, the local landowners and industrial water consumers had no reason to tap the lower aquifer, so much less is known about the Dockum aquifer, affecting the detail available to the authors and others interested in the local conditions. A label and arrow were added in Figure 2 to show the site location in Seminole, near the 5000 mg/L TDS contour. It is obvious that there were few historical data points near the project sites from the waterbased literature. The state database also had little lithological information to go with the historical water samples, so the number and position of water-bearing zones in the Dockum was unclear. Anecdotal information from local well drillers indicated that at least two different water-bearing layers might be encountered, one at less than 1000 ft of depth below ground surface and a second near the bottom of the Dockum about 2000 ft below ground surface. Engineers from Parkhill Smith and Cooper, Inc. (PSC) were retained to produce the well specifications according to Texas Commission for Environmental Quality requirements and assist in the procurement process. The location for the brackish ground water well, referred to as SR-1, was set by the City at latitude 32º 41’ 06.415”N, longitude 102º 40’ 0.727”W, at the local elevation of approximately 3300 ft

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above mean sea level. This site is located within 510 acres on the south side of Seminole recently purchased for installation of additional Ogallala water supply wells. Cirrus Associates (Cirrus 2009) evaluated available nearby geophysical logs and constructed north-south and east-west cross sections to describe the subsurface conditions and project potentially productive zones in the Dockum aquifer prior to the procurement of the drilling contract. Cirrus (2009) identified two possible productive zones, from 450 to 580 ft below ground surface in the upper Dockum (Trujillo Formation) and from 1440 to 1840 ft below ground surface in the lower Dockum (Santa Rosa horizon). The drilling contract was awarded to West Texas Water Well Service (WTWWS) for an 1800 ft well, and the drilling was completed in July 2011. To protect the shallow Ogallala aquifer, 12.25 in steel surface casing was placed and cemented in a 17.5 in hole to a depth of approximately 274 ft, terminating about 100 ft below the base of the Ogallala and the underlying Cretaceous layer. An 11 in hole was advanced below to a total depth of 1808 ft, and a 7 in steel casing was installed and cemented. Cirrus (2011) collected samples for the geologic log. Geophysical gamma and neutron porosity logs were run by E-P Wireline/Schlumberger. The logs were interpreted by Dr. Judy Reeves of Cirrus and

Figure 3. Drawdown and pumping rate during the 36 hr pumping test on August 4-5, 2011.


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Dennis Powers, another geologist who consults with WTWWS on deep wells. The most promising zones were noted from 540-650 ft, 890-920 ft, and 1610-1770 ft. The three zones were perforated with two perforations shot per foot. WTWWS performed well development and pump testing in early August. The initial depth to water was 743 ft, which was below the uppermost perforated interval. A 36 hr pump test was performed with the pump intake set at 1600 ft. Figure 3 shows the records of pumping rate and drawdown in the pumping well vs. time for the next 36 hr. The drawdown stabilized at approximately 180 ft in less than 30 min and remained at that value for the rest of the test duration. The pump was then turned off, and the well recovered to a stable depth to water of approximately 746 ft within 30 min. These results were very encouraging, as the stable pumping rate of 150 gpm was three times the target of 50 gpm planned for the demonstration project. The position of the water column in the well allowed selection of a pump with its intake less than 1000 ft from the ground surface, which fell within the range of commercially available water well pumps. The original budget for the well included a 50 gpm pump with its intake planned near the bottom of the well, at a nominal 1800 ft depth, which would require a more expensive and unique pump configuration. The pump selected was a Grundfos Model 85S20018, 20 hp pump to deliver 50 gpm at 900 ft of total dynamic head. An unofficial water sample was found to have TDS of 7130 mg/L, and it was unclear how waters from one or more producing zones might be mixing. Project funding did not allow for a packer test to separate and sample from the perforated zones. An In-Situ Data Troll® was installed downhole just above the pump to monitor water level (as proportional to pressure head), temperature, and electrical conductivity (which can be converted to TDS) over time. The datalogger was set to record data on 10 min time intervals.

Reverse Osmosis Treatment System PSC engineers also assisted with the procurement of the RO system for the demonstration project based on their previous experience with similar treatment projects and Texas Commission for Environmental Quality

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regulatory requirements. The general goal of the specification was a complete operational skid-mounted RO system to treat an inflow of at least 50 gpm of brackish water to meet the Texas Commission for Environmental Quality’s primary drinking water standards, with pretreatment capability for cartridge filtration, pH adjustment, and antiscalant addition. The target recovery factor was at least 70 percent with a salt rejection rate of 95 percent and minimum membrane life of two years. The RO system was purchased from Crane Environmental in December 2010 with Texas Tech Department of Energy funds. Concentrate management is an important aspect of any desalination system. Alternatives considered included an evaporation pond, additional RO for the concentrate flow, and discharge into the City’s wastewater collection system. After discussion with PSC and the City staff, the choice for this demonstration project was to simply blend the permeate and concentrate flows in a lift station and pump the mixture into the City’s wastewater collection system. This alternative would require the least attention from the City staff, and the flow rate would be small enough to easily dilute into the City’s wastewater flow without impacting the wastewater treatment plant. The lift station and associated sewer line were designed by West Texas Consultants and constructed in 2012. A 30 ft by 30 ft metal building was constructed at the site to contain the RO system. The building and the infrastructure between the well and the RO system were also designed by West Texas Consultants and constructed in 2012. Electricity from the local grid connection was also included, so that the well and RO system can operate continuously, not just when sufficient wind energy is available.

Wind Turbine The 50-kW wind turbine was purchased from Entegrity Wind Systems, partnered with West Texas Consultants and construction contractors for the site engineering and installation. The turbine’s nacelle and blades are supported by a 100 ft galvanized steel lattice tower, and the blades are 23.7 ft long, resulting in a rotor diameter of 49.2 ft at a centerline hub height of 102 ft. The nominal


Renewable Energy for Municipal Water Desalination maximum height of the turbine is 127 ft, and an appropriate Federal Aviation Administration determination of no hazard to air navigation was required because of the proximity of the turbine to the Seminole Airport. Both the wind turbine and the local electrical grid are connected to the RO building with two separate meters so that the contributions of both sources can be tracked over time. During the demonstration period, the well and RO system will be run continuously, using renewable wind energy when available and grid electricity otherwise. The seasonal variations in wind energy generation are of primary interest. Final commissioning of the wind turbine was imminent at the time of this manuscript.

Initial Operation After the RO system was installed and grid electricity was available, initial startup was scheduled in the fall of 2012 with representatives of Crane Environmental, even though the wind turbine had not yet been commissioned. Surprisingly, the static water level in SR-1 rose from its temporarily stable 740 ft below ground surface after drilling and development to about 96 ft below ground surface over several months. The certified cementing of the surface casing must be preventing any inflow to SR-1 from the shallower Ogallala aquifer, so the higher water level must be caused by the pressure in one of the

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three perforated zones. It was unknown whether this shallower static water level would persist during continuous operation or if the static water level would drop back to the 740 ft below ground surface noted after development, so the research team chose to observe the water level variations caused by temporary pumping events such as those that might follow the startup event. In anticipation of the startup event, an official water sample was collected by PSC from the SR-1 well after one hour of continuous pumping for laboratory analyses at TraceAnalysis, Inc., in Lubbock. Table 3 summarizes the results of those analyses, and provides a comparison to the water quality reported for the City of Seminole’s nearby new Ogallala well, denoted as AK in the table. The TDS level of 2330 mg/L was well below the 7130 mg/L reported in the grab sample in July 2011, which was collected with a temporary pump set at 1600 ft below ground surface. It is apparent that some mixing between two or more of the perforated zones must be occurring in the well, and that mixing process would of course be influenced by running the pump. Typically, TDS increases with depth, so the lower TDS water was likely from one of the two upper perforated zones. Startup of the RO system with Crane Environmental, City of Seminole staff, and PSC took place on October 2 through 5 using grid-based power. According to the Crane representative, the RO system operated properly and dropped the

Figure 4. Drawdown and total dissolved solids variations during January 2013.


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TDS in the water from over 2000 mg/L to less than 100 mg/L easily. Several City of Seminole water staff members were trained on the operation of the RO system, and they ran the well and RO system for 30 min to 1 hr three to five days per week to prevent deterioration of the membranes and other parts of the system. Figure 4 shows the changes in drawdown of the water level and TDS during January 2013. While the water level recovered quickly, the TDS value felt by the sensor above the pump rose from about 2000 mg/L to as much as 10,000 or over 30,000 mg/L after the pump was turned off for about 15 hr, then dropped back to the 2000 mg/L level, indicating significant mixing within the well as the water level changes. Hydraulically, the water level in SR-1 typically dropped about 200 ft or more when the pump was on, then returned within an hour or so to 96 ft below ground surface. Under these conditions, the intake side of the well pump experienced much greater pressure than expected, such that the discharge flow rate and pressure were much higher than the 50 gallons per minute and 10-15 psi expected by the variable speed booster pump between the well pump and the RO system. The short-term mitigation of this issue was to divert part of the well discharge to simply flow into the farmland near the well head using a tee and valve and thus control the flow and pressure to the booster pump. The long-term fix for this unexpected condition was installation of a variable frequency drive and pressure transducer to control the well pump, reducing the motor speed from 60 Hz to 35 Hz to deliver the proper flow and pressure of 40 to 60 psi to the RO system. This addition rendered the intermediate booster pump unnecessary, and it was removed. Continuous operation of the complete system began on April 18, 2013, starting with a 24 hr test period with the direct assistance of the Crane Environmental field representative overseeing the City of Seminole water utilities staff. The team monitored system performance on the RO system’s touch-screen monitor, which reported permeate and concentrate flows, pressures, conductivities, and pH values, as well as the incoming raw water conductivity, pH, pressure, and temperature. A hand-held Myron L™ water quality instrument provided an alternate means of checking conductivities

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and pH values with grab samples from various sample valves around the system. As the system ran during the first 24 hr, the team noted that the incoming raw water conductivity slowly rose from about 3600 to 13000 µs/cm, which respectively corresponded to TDS values of 2300, as in the sample collected in August 2012, to 7000 ppm, as in the sample collected during the 36 hr pump test. This higher TDS value indicated the long-term pumping caused mixing with in the well, and the RO system design and operation easily accommodated this feedwater condition. The permeate and concentrate flow rates settled at 40 and 14 gallons per minute, respectively, for a volumetric recovery rate of 74 percent, and the permeate TDS value stabilized at about 450 ppm. The system ran continuously until May 2, when the well pump motor failed due to an electrical ground fault. The pump and motor were pulled by a local pump contractor, who then ordered a replacement 20 hp motor. The new motor and pump were reinstalled on June 14, and the complete well and RO system were restarted on June 17. Even after being idle for six weeks, the RO system’s operating conditions stabilized to the same flow and parameter values established previously in April. This document was completed in June 2013, as the official 12-mo demonstration period began. The demonstration project will run for 12 months, as we collect operational data on the amount of water pumped and treated, electrical usage from both wind turbine and grid sources, and the performance of the RO system. City staff will have primary responsibility for day-to-day operations, with support from the Water Resources Center researchers. A final report will be prepared in summer 2014.

Conclusions This project demonstrates a new approach to municipal water supply and treatment that can be applied in west Texas and other locations with access to brackish ground water and wind energy. Most often, power generators think only of their needs to produce and sell electricity to customers across their region, while municipalities either have to obtain and treat their own local water


Renewable Energy for Municipal Water Desalination supplies or purchase the water and/or treatment from a water utility. Rural communities with less than 10,000 population may struggle with purchase and operation of the necessary infrastructure to meet both the volumetric water demands and the regulatory drinking water standards. The project team will provide operational and financial data from this 12 month demonstration that will allow both the City of Seminole and other municipal decision- makers to quantitatively consider similar options under similar conditions. In general, properly designed RO systems tend to work well no matter the source of electricity. The technical elements of this project have previously been proven independently successful, and this project basically brings the technologies together in an unusual combination. The combination of technologies required significant funding beyond the City’s means, so multiple sources of grant funds were aggregated from state agencies, the LEUWCD, and the Texas Tech WiSE and Water Resources Center research funds. Cooperation between the funding agencies and various vendors was facilitated by AJ Howco Services. Procurement and installation of the Dockum well required the assistance of PSC and Cirrus consultants to reduce the budgetary uncertainties and confidently meet Texas Commission for Environmental Quality regulations for drinking water wells. The assistance of PSC was also important in procurement of the RO system and identifying appropriate vendors. Texas Tech researchers were able to lead the wind turbine procurement, and collaboration between West Texas Consultants and EWS was necessary to meet engineering and financial requirements within the budgeted funds. West Texas Consultants led the design and construction management for the site infrastructure with input from the Texas Tech team and PSC. The City water department staff accepted their roles in the present and future operation of the demonstration project. All parties involved look forward to the coming 12 month demonstration period. The project results should be informative for other rural municipalities in the region that are considering renewable energy applications, brackish ground water treatment, or both.


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Acknowledgments The authors wish to express their gratitude to several people who make this project possible. First, we thank the City of Seminole city administrator Tommy Phillips, former mayor Mike Carter, current mayor Wayne Nixon, the city council, superintendent Gary Duncan, and water foreman Tommy Williams for their support and hands-on participation. Funding and cooperation were provided by Travis Brown of the Texas Department of Agriculture and its Office of Rural Affairs, Sanjeev Kalaswad and Jorge Arroyo of the Texas Water Development Bureau, Pamela Groce of the State Energy Conservation Office, and Lori Barnes and the Board of the Llano Estacado Underground Water Conservation District. Kay Howard of AJ Howco served as contract administrator for the City and the state agencies. Gil Gillespie and West Texas Water Well Services drilled the well and installed the initial pump. Technical consultants included Judy Reeves of Cirrus Associates for hydrogeologic services, Zane Edwards, Leonard Nail, John Kelley, and Daniel Albus of Parkhill Smith and Cooper for well and RO system specifications, and Chad Tompkins and Jon Link of West Texas Consultants for site design and construction oversight. Jim Heath of Entegrity Wind provided the 50-kW wind turbine in cooperation with West Texas Consultants. David Anderson of Anderson Welding Pump and Machine Service installed the VFD for the pump motor and the replacement motor. Jim Almond and Keith Summerford of Crane Environmental oversaw the installation and operation of the RO system. The Water Resources Center and Wind Science and Engineering Center were funded through a grant from the Department of Energy.

Author Bios and Contact Information Ken Rainwater, after receiving his Master’s and Ph.D. in Civil Engineering from the University of Texas, joined Texas Tech University in 1985 and has served as the Director for the Texas Tech University Water Resources Center from 2002 to 2012. Dr. Rainwater’s research focuses on water resources management, ground water flow and contaminant transport, ground water rights, remediation of contaminated soil and ground water, and watershed management. He is the principal or co-principal investigator on several ongoing projects, which include field observations of recharge to the Ogallala aquifer, impacts of climate variability on surface and ground water resources, and watershed management through removal of nuisance vegetation. Texas Tech University Water Resources Center, Box 41023, Lubbock, Texas, 79409-1023. He can be reached at: [email protected].

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Phil Nash received his B.S. and M.S. degrees in Civil Engineering from Texas Tech University. He recently retired after 6 years as the Director of the Texas Tech Center for Multidisciplinary Research in Transportation. His prior positions included senior researcher at Texas Tech and Southwest Research Institute, and as research engineer and vulnerability analyst with the Air Force. His primary research interests include renewable energy systems, structural dynamics, weapons effects, and transportation engineering.Texas Tech University Water Resources Center, Box 41023, Lubbock, Texas, 79409-1023. Email: [email protected]. Lianfa Song earned both his B.S. and M.S. degrees from the Peking University, China, and his Ph.D. degree from the University of California, Los Angeles. Dr. Song previously taught at Beijing Normal University, Hong Kong University of Science and Technology, and the National University of Singapore as assistant professor. He is currently an associate professor in the Department of Civil and Environmental Engineering, Texas Tech University. Dr. Song’s major research interests are physical and chemical processes in water and wastewater treatments with a recent focus area in membrane science and technology in water desalination and purification. He has published over 70 research papers and book chapters.Texas Tech University Water Resources Center, Box 41023, Lubbock, Texas, 79409-1023. Email: lianfa.song@ ttu.edu. John L. Schroeder, Ph.D., is the Director of the National Wind Institute and a Professor in Atmospheric Science at Texas Tech University.. His focus includes relating the meso, micro, and turbulence scales of the atmosphere to the applied engineering communities. Dr. Schroeder has worked with Sandia National Laboratories and Vestas to develop the Scaled Wind Farm Technology (SWiFT) Facility at Texas Tech University. He led the development of several noteworthy atmospheric observation platforms including the StickNet platforms and Texas Tech Ka mobile research radars, and the expansion of the West Texas Mesonet to more than 70 surface stations and an integrated SODAR network.National Wind Institute, Texas Tech University, Box 41023, Lubbock, Texas, 79409-1023. Email: [email protected].

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References Arroyo, J. 2011. Updates on TWDB’s Innovative Water Technology Programs, Report to Texas Water Development Board, Austin, Texas. Available at: http://www.twdb.state.tx.us/innovativewater/ doc/20110405_Updates_IWT_Program.pdf. Bradley, R. and S. Kalaswad. 2003. The Ground Water Resources of the Dockum Aquifer in Texas, Report 359. Texas Water Development Board, Austin, Texas. Center for Geospatial Technology. 2006. Estimated Usable Aquifer Lifetime, Ogallala Map Series, Texas Tech University Available at: http://www. gis.ttu.edu/OgallalaAquiferMaps/MapSeries.aspx. Cirrus Associates, LLC. 2009. Evaluation of the Proposed Well Location for a Municipal Water Supply Well in the Dockum Aquifer, Gaines County, Texas, Project No. 02-013600.03, Report to Texas Tech University Wind Science and Engineering Center, Lubbock, Texas. Cirrus Associates, LLC. 2011. Geology Report Dockum Well SR-1, City of Seminole, Gaines County, Texas, Project No. 02-013600.01, Report to Texas Tech University Water Resources Center, Lubbock, Texas, 68. Ewing, J., T. Jones, T. Yan, A. Vreughenhil, D. Fryar, J. Pickens, K. Gordon, J. Nicot, B. Scanlon, J. Ashworth, and J. Beach, 2008. Groundwater Availability Model for the Dockum Aquifer. Final Report, Texas Water Development Board, Austin, Texas. Swift, A., K. Rainwater, J. Chapman, D. Noll, A. Jackson, B. Ewing, L. Song, G. Ganesan, R. Marshall, V. Doon, and P. Nash. 2009. Wind Power and Water Desalination Technology Integration Report 146, Bureau of Reclamation, Denver, Colorado. Texas Water Development Board. 2013. Texas Reservoirs, Water Data for Texas. Available at: http://waterdatafortexas.org/reservoirs/statewide, accessed February, 2013.
