‘Greatest water quality improvement project in world’
International Colorado River group meets and hears case for new methods for salinity control
The Colorado River Citizens Forum met in Yuma on Wednesday to hear from two experts in water issues related to the Colorado River, one of whom was an expert in salinity control.
The forum is organized by the U.S. section of International Boundary and Water Commission, a binational body run in the U.S. and Mexico to enforce water agreements between the two countries.
Delivering updates to the forum on salinity control efforts for the Colorado River was Don Barnett, the executive director for the Colorado River Basin Salinity Control Program, a program directed by the Secretary of the Interior and acting through the
Bureau of Reclamation to control salinity levels for the water in the Colorado River.
“I, for some time, have been calling this the greatest water quality improvement project in the world,” he said. “Nobody has really been giving me challengers, and I haven’t found any.”
Barnett said the reason for his pride and confidence in the program he works for lies largely in the success it’s had in reducing the quantity of salt flowing downstream in the Colorado River and in improving the quality of water individual users and farmers receive in places like Yuma.
With the more than $1 billion spent annually on the program, the Colorado River Basin Salinity Control Program now averages an annual reduction in the salt content of the Colorado River by more than 3 million tons, Barnett said.
Estimates by the Bureau of Reclamation presented by Barnett say that the quantifiable damages from high salinity water are about $454 million per year to U.S. water users. The estimates say that amount would increase $120 million if the Salinity Control Program were not “to continue to be aggressively implemented.”
Barnett explained that 300 million years ago, the Earth’s geography had California and Mexico underwater with Yuma roughly on a shore. As that ocean water receded, it left behind an inland sea called
the Western Interior Sea that connected to the Gulf of Mexico. The salt in the Colorado River comes from what’s left over after the departure of the ocean and seawater that formerly covered most of the continent.
“I’m more or less comfortable saying there’s an infinite amount of salt waiting to make its way into the water,” Barnett said.
Barnett’s presentation focused mostly on salt coming from the Dolores River in western Colorado, which runs across the Paradox Valley. The valley gets its name because the Dolores River counterintuitively runs across the valley rather than down it because the river’s course was formed by fractures in the earth’s surface rather than gravity. This means that the Dolores River, a tributary to the Colorado, is in constant contact with the salt leftover from those prehistoric oceans and seas, which left most of their salt under rock and shale on the earth’s surface.
A big part of Barnett’s job is reducing the salt that will inevitably get in via the Dolores before it travels south to places like Yuma. Although Yuma has a Bureau of Reclamation office that does salinity control, their job is limited to salinity control in the area and of water traveling to Mexico through Morelos Dam.
The Bureau of Reclamation in Yuma has a desalting plant that uses reverse osmosis to take the salt out at a molecular level. However, the plant remains on stand-by, and if it were to be activated, it would only treat water traveling between Imperial and Morelos Dam and the surrounding
area.
Furthermore, to meet the needs in the upper basin, reverse osmosis wouldn’t do. Barnett needs a process that prevents salinity more than it desalinates.
The Yuma Desalination Plant is meant to remove brackish water, a mixture of salt water and fresh water that typically accumulates with large amounts of groundwater runoff. Barnett and the Salinity Control Program treat brine water, which is very salty water that comes from underground and brings a large amount of salt from deposits of rock and shale.
Brine water like the water that streams from the Dolores River and into the Colorado River is what Barnett is trying to desalinate, which means he’s not treating the Colorado River for desalination directly, but rather heading off a significant source of its salt.
To remove salt from a tributary like the Dolores River, the Salinity Control Program uses injection wells, which pumps water deep underground through rocks with pores like limestone or sandstone to filter out the salt.
“The problem with this is that we’re basically fracking rocks and creating earthquakes by injecting salt into the earth,” Barnett said.
Now, Barnett and the Salinity Control Program are looking for alternatives that can keep up with the injection wells, which treat more than 200 gallons of water per minute.
An idea like reverse osmosis wouldn’t work because the Colorado River water is used industrially and residentially. Reverse
osmosis creates bottle-quality water that can be consumed but creates problems for residential and industrial use like seepage through pipes. When the desalting plants use reverse osmosis, they tend to harden it again before it’s distributed.
The alternative that the Salinity Control Program understands the most is evaporation ponds. This method effectively recreates the water cycle and the way freshwater is created by putting water in manmade ponds so that it can be evaporated with heat and leave the salt behind.
However, Barnett said that there’s also favor toward a fairly new method called Brine Crystallization. This means using pressure to condense the salt into crystals that are easier to remove. Barnett said that this method is low energy, which means it has environmental and economic benefits, but it’s also low yield, which means it’s slower. Still, Barnett said he sees the method as a promising, innovative and long-term solution.
“This is something a few years ago we weren’t even talking about, but now we’re here talking about it,” he said. “Where do we want to go for the next 50 years with this? The states swallow most of the costs on this, so this concerns them. We want a solution that they’ll work with.”
The Bureau of Reclamation offices in Western Colorado that operate Paradox Valley water treatment facilities have already started assessing brine crystallization technology as an alternative, but the problem they’ve run into
is what to do with the salt they leave behind.
“They couldn’t find anyone to take the salt after pumping it up,” Barnett said. “They put out ads telling people that they were giving away salt: no one came. They couldn’t even pay people to take it.”
A similar concern comes up with evaporation ponds. Traditional evaporation ponds have man-made salt basins that accompany them. However, these have created environmental concerns. The primary concern has been that the salt damages the ecosystem around the water and destroys food sources for migratory birds. The salt also has to be sprayed down regularly so that it doesn’t blow away and damage air quality.
The Salinity Control Program has run through what seems to be every conceivable use for the salt, Barnett said, but few stick. They’ve heard suggestions of using the salt for icy Colorado roads, but the concern is that snow would melt and the runoff would carry the salt back to the river. The quantities of salt being collected are also too high to disappear by becoming road salt.
Either way, Barnett said, the Salinity Control Program needs a way to control the salt coming out of the Dolores River for the benefit of everyone downstream, especially farmers.
“Salinity damages in the upper basin means damages in the lower basin that are significant,” Barnett said. “Water users in the lower basin will feel any changes in the upper basin. If you have a farm of head lettuce, leafy lettuce, your
productivity is sensitive to this high salinity level. The farmers will be the first to notice high salinity levels. Most of the damage happens to ag users.”
Downstream also includes Mexico, and high salinity levels affect U.S. relations with Mexico. Part of the Bureau of Reclamation’s job in Yuma is to check that the water going to Mexico across Morelos Dam meets a salinity standard specified in a 1944 water treaty with Mexico.
The most immediate solution Barnett sees is to continue to support the Salinity Control Program, which he proudly calls the “greatest salinity control program in the world.” The program is funded annually by the congressional appropriations process, so every year the program has to make a case for Congress to continue funding them.
However, Barnett said, that can be difficult because the better the program does their job, the more invisible they become. For them, obvious scenarios for attention would be negative, so they need public support.
“For those affected, for those concerned, write to Congress. It’s a way to make a difference, and we could use that support. One of the problems is that there’s no pizzazz to what we do,” Barnett said. “If we’re doing our job right, no one should know who we are. It’s like the way we are with our local water treatment facilitator. No one knows who he is until the water’s brown, then his picture’s on the front of the newspaper.”