Technology for treating saline groundwater for agriculture

July 11, 2016

A new water resource for agriculture

The issue of freshwater supply is a critical factor of future U.S. global prosperity, national security and economic development. As droughts and water shortages persist, a greater need has arisen to conduct research on the development of low-cost energy technologies that could treat saline groundwater cheaply in large enough volumes for use in crop irrigation. Some of the most promising research and development (R&D) to date uses high-negative ion flux, along with static and variable low-frequency and radio-frequency electromagnetic fields to produce significant effects on water molecules, salt cations and organisms that distinguish it from related technologies.

This area of R&D suffers from its association with low-frequency electromagnetic fields. Its causes and effects are considered by many scientists to be pseudoscience, whereas the real problem is a lack of performance testing in paired field trials conducted by independent and qualified third parties with standardized testing protocols under a range of environmental conditions using treated and untreated (control) low-salinity groundwater (LSGW) from 1,500 to 9,000 mg/l total dissolved salts (TDS).

Figure 1. Depth to saline groundwater in the United States (generalized from Feth and others, 1965). Image courtesy of USGS

The map (see Figure 1) initially produced in 1950 by the U.S. Geological Survey (USGS) on the distribution of saline groundwater has not been updated since 1965. The USGS is currently conducting a study to identify and determine the characteristics of the significant brackish water sources in the U.S. This study is slated to be completed in September 2016.

However, given the estimated total volume of water on earth, the estimated volume of saline groundwater is 0.94 percent, and the volume of available freshwater is 0.76  percent.

In 2011, a consultant was hired to organize a series of paired field tests with farmers using a patented technology developed in the 1980s and subse­quently modernized by TransGlobal H2o LLC (TGH2o) in Houston, Texas, to develop scientific data for the validation of crop production benefits. Using TGH2o technologies to treat saline groundwater, the long-term goal was to validate a decade of farmer antidotal benefits and to optimize the technology for different crops, soils and environmental conditions.

Photos courtesy of TransGlobal H2o

Units previously demonstrated reduction in corrosion and scale formation in irrigation pumps, pipes and sprayers, and maintenance, with increased pump water volumes and lowered electricity use. The theory the technology uses is a two-step process,  which first introduces a negative charge into irrigation water, similar to the effect of lightening in clouds. In the first step, the introduction of the negative charge increases hydrogen bonding of water molecules making the water more negative, increasing surface tension, adhesion, cohesion and surface tension of these water molecules. This makes the irrigated soil stay wetter longer, such as when the treated water evaporates slower because of increased hydrogen bonding, and therefore is more available for seed germination and plant growth.

In paired field trials (2013 to 2015), farmers reported increases in crop production/acre of treated over untreated saline groundwater with an electricity cost of less than $10 per month for 300 or more acres depending on soil types and irrigation application methods (ditch, spray or drip irrigation) in several crops:

  • 7.5 percent organic strawberries
  • 14 to 17.4 percent lettuce and spring mix
  • 70 percent barley and oats

Photos courtesy of TransGlobal H2o

1984 ‘peak water’

In 1984, water use reached "peak water," leveled off at 260 billion gallons per day (bgd) by all uses, where it has remained since (±2 bgd). As drought conditions persisted in the U.S., the focus became reducing the 80 to 90 percent of water used in agriculture by implementing new irrigation technologies and water use restrictions. Low-energy, low-cost technologies were needed to treat LSGW for use in irrigation. Current desalination technologies are expensive because of the volume of water (34 percent) required for irrigation in agriculture.

Current droughts

Figures released on May 15, 2016, by NASA show that global land and sea temperatures were 1.11ºC warmer in April than the average temperature for the month from 1951 to 1980. These temperatures led to the hottest April on record globally and made it the seventh month in a row to have broken global temperature records.

The latest figures smashed the previous record for April by the largest margin ever recorded. That made three months in a row that the monthly record was broken by the largest margin ever, and seven months in a row that were at least 1ºC above the 1951 to 1980 mean for that month. When the string of record-breaking months started in February, scientists talked about a climate emergency. This emergency will significantly impact crop production in the second half of 2016 in the southern and western states, when less freshwater will be available for irrigation.

Comparison of seedpods after 80 days, more than 1.5 times more seeds per seedpod. Photo courtesy of TransGlobal H2o

Results of paired field trials

Paired field trials were conducted in Buckeye, Arizona (barley and oats); Camarillo, California; (four varieties of spinach and spring mix); and Salinas, California (organic strawberries), using treated and untreated LSGW in test plots. These tests found increased treated crop production/acre: 70 percent (barley and oats during 120 days); 15 to 18 percent (spring mix and spinach, 30-day crops); and 7.5 percent for (organic strawberries). The trials were designed to deliberately test for measurable differences in plant development, growth and crop production in poor soils using treated and untreated LSGW for irrigation 1,500 to 4,000 milligrams per liter (mg/l) total dissolved salts (TDS).

The technology has been used by farmers to treat irrigation water in California, Arizona and Texas for the following crops during the past decade:

  • Strawberries (bedded up, on drip irrigation, sometimes sprinklers, from a well)
  • Wine and table grapes (sometimes on drip, sometimes on sprinkler, from a well)
  • Oranges and avocados (rotary spray at the base of the tree, from a well)
  • Lettuce and spring mix (sprinkler, from a well)
  • Cauliflower, cabbage and broccoli (sprinkler, from a well)
  • Ornamental flowers (sprinkler from a well, sometimes from a reservoir)
  • Beans (drip or sprinkler, from a well)
  • Tomatoes (drip, sometimes sprinkler, from a well)
  • Broccoli (sprinkler, from a well)
  • Corn (ditch irrigation, from a well)
  • Cotton (ditch irrigation, from a well)
  • Sorghum (pivot irrigation, from a well)
  • Golf course grass (sprinklers, from a well)

To date, four cooperative farm demonstration projects have been conducted, and four more are underway. These paired field trials were designed to deliberately test for measurable differences in plant development, growth and crop production. Results of irrigation with treated versus untreated water from these studies and from L.D. Hardesty’s paired field trials with barley and oats (Buckeye, Arizona) included:

  • Faster seed germination occurred by seven days, and root hairs developed.
  • More seeds germinated by five times per unit area.
  • Faster root growth was seen by five to seven days.
  • Faster plant growth and leafing out occurred with healthier, greener plants.
  • Plants were twice as tall with bigger leaves and increased flowering.
  • Faster seedpod germination and seed development was seen in seedpods by 10 days.
  • One and a half times more seeds were produced per seedpod.
  • Significantly reduced plant death from osmotic stress occurred in plants irrigated with treated water than those irrigated with untreated water when both were subjected to a 2-inch rain fall that dissolved deposited soil surface salts.
  • Significantly reduced plant stress and death (desiccation) occurred because of exposure to heat from high air temperatures (110°F to 118°F) and during periods of high, dry winds in test sites irrigated with treated water.
  • Soil salinity analysis of six surface soil samples (0 to 8 inches) were collected from three rows and two depths (0 to 4 and 4 to 8 inches) from the treated and untreated test plots found in ditch irrigated treated soils. The following results were observed:
    • a. Mean salinity was 39 percent lower.
    • b. Mean sodium was 42 percent lower.
    • c. Mean nitrogen was 38 percent lower in treated soils (taken up by plants) after four months of treated row irrigation. Soil salinity analysis of soils irrigated by drip irrigation (four months) were 20 percent lower in soluble salts (organic strawberries).
  • Soil irrigated with treated water remained wetter longer (24 to 36 hours) than untreated water, providing water conservation of 25 to 30 percent.

Paired field trials with organic strawberries

In field trials during the past three years, farmers have reported a 7.5 to 70 percent increase in crop production per acre (30-day to 120-day crops) with an electricity cost of less than $10 per month to irrigate more than 300 acres. The technology has been used in 2- to 14-inch irrigation pipes to treat saline water from 1,500 to 9,000 mg/l TDS and treated hydraulic fracturing/produced water (200,000 mg/l TDS, which is 6.25 times the salinity of seawater).

Author’s note: I would like to thank L.D. Hardesty, his son David and his grandson Dan for their knowledge and assistance in conducting the study in Buckeye, Arizona.

Michael A. Champ, Ph.D., is a consultant to TransGlobal H2o in Houston, Texas. He has held senior positions in academia, government and industry, assessing toxic effects of chemicals in aquatic and marine environments and conducting due diligence to assess the benefits of new advanced environmental technologies. He can be reached at [email protected]. Learn more about TransGlobal H2o at

Sponsored Recommendations

NFPA 70B a Step-by-Step Guide to Compliance

NFPA 70B: A Step-by-Step Guide to Compliance

MV equipment sustainability depends on environmentally conscious design values

Medium- and low voltage equipment manufacturers can prepare for environmental regulations now by using innovative MV switchgear design that eliminates SF6 use.

Social Distancing from your electrical equipment?

Using digital tools and apps for nearby monitoring and control increases safety and reduces arc flash hazards since electrical equipment can be operated from a safer distance....

Meet the future of MV switchgear

SureSeT new-generation metal-clad. Smarter. Smaller. Stronger.