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Drillers from the drilling company Boart Longyear, which is headquartered in Salt Lake City, are working on a well for Rudd Farms. When the well is done, it will reach between 3,000 to 4,000 feet below the surface, making it the deepest irrigation well in Oregon, according to Brett Rudd of Rudd Farms. Chris Baxter/The Observer
Large rig drilling deepest irrigation well in Oregon northeast of La Grande
by Kelly Black/For The Observer
A well being drilled in rural Union County may help expand a scientific understanding of sub-surface water flows in the Grande Ronde Valley.
A large rig is drilling 3,000 to 4,000 feet down into the basalt in search of water for Rudd Farms, which is about seven miles northeast of La Grande on Wallsinger Road.
“It will be the deepest irrigation well in Oregon,” said Brett Rudd, who is the co-owner of Rudd Farms.
Depending on the well and how it was designed, deep wells through the basalt can cost anywhere from $1 million to $3 million, according to Robert Stadeli, business development manager at drilling company Boart Longyear, which is headquartered in Salt Lake City. Some owners, like Rudd, defray costs by supplying things like materials and fuel.
“I caught them in-between jobs at a good time,” said Rudd. “I can keep costs lower.”
Well drillers estimate the cost to drill a well by the foot. Rudd said that while shallower wells into the upper alluvial layer run approximately $100 per foot, a deep basalt well can cost around $300 a foot.
Rudd chose Boart Longyear for the project because of the confidence he has in its technique and equipment, including its reverse circulation drilling process, a special mud tank and onsite lab analysis.
“They have drilled all over the world,” Rudd said. “The crew has given me a lot of confidence.”
Stadeli estimates drilling crews will be working on the Rudd Farms’ well for six to eight weeks.
Rudd hopes to recoup costs of installing the well within seven years.
“Of course, this depends on the weather, the market and the Chinese,” Rudd said.
The Chinese are one of the world’s biggest buyers of corn, wheat and soybeans.
“If I get water, it should triple production on dry land farming,” said Rudd.
Currently, Rudd uses dry land farming techniques that requires two years of moisture to get one crop by allowing the land to lie fallow. When Rudd plants winter wheat, he gets about 80 bushels per acre every two years. With irrigation, this could increase up to 110 bushels per acre each year.
Irrigation would also allow Rudd to raise higher value crops like grass seed and peppermint.
Rudd’s initial irrigation plan involves running three center pivots that will cover 480 acres. Each pivot requires about 1,100 gallons of water per minute.
“I’m hoping to have 2,000 GPM,” Rudd said.
A lesson in geology and water rights
Below the topsoil, the Grande Ronde Valley has layers of sands and gravels intermingled with silts and clay called the alluvial layer. This layer can run up to 2,500 feet deep in places. Below this layer is about 1,000 feet of the Powder River Volcanic Field and then the deep Columbia River Basalt, which was formed from lava flows. Regional geological maps show that the Columbia River Basalt can extend to depths of 1,000 feet below sea level in the Grande Ronde Valley.
The top alluvial layer has been utilized extensively for irrigation and other purposes. According to Water Master Shad Hattan, the Oregon Water Resources Department is generally not issuing new water right permits for this top layer unless the user can mitigate for impacts.
“Permits are generally being denied,” said Hattan.
Farmers, like Rudd, seeking new water rights must drill into the Columbia River Basalt.
According to Hattan, a number of wells in the Grande Ronde Valley penetrate the basalt including municipal wells in La Grande, Imbler and Union and some irrigation wells near Imbler.
Drilling into the basalt involves satisfying state requirements as well as highly sophisticated drilling equipment.
In order to maintain separation between water in the upper alluvial layer and the lower basalt aquifer, Rudd must use 16-inch well casings surrounded with about three inches of concrete down through the upper alluvial layer until he reaches 20 feet into the solid basalt.
Even with an experienced drilling company, working with Oregon state geologists and a years worth of pre-planning, there are a lot of unknowns.
According to Rudd, the geologists’ first guess was that he would hit basalt at around 1,950 feet.
“We’ve drilled 2,500 feet and just hit our first signs of basalt,” Rudd said.
Geologists will analyze the mineral content of the rock to determine if the basalt is upper Powder River volcanics or the deeper Columbia River Basalt. Rudd has to drill into the lower Columbia River Basalt.
At 1,950 feet the crew drilled through a big chunk of tree. They got wood chips about three inches long.
“It smelled like wood and looked like wood,” Rudd said.
Creating a groundwater model
Some in the community have expressed concern about tapping into what they call an ancient aquifer deep in the Columbia River Basalt.
According to a 1985 U.S. Geological Survey report, pumping from the Columbia River Basalt for irrigation in Morrow and Umatilla counties resulted in regional level water decline.
The permit for Rudd’s well requires annual water level measurements that will help monitor ground water levels and recharge of water into the aquifer, according to Ivan Gall, manager of the Groundwater Group at the State of Oregon Water Resources Department. Gall hopes to work with Rudd to get quarterly readings.
A measurement taken in March before the irrigation season might show a higher water level then a measurement taken after the irrigation season. But another measurement taken the following March should show a replenishment of the water level, so that the March water level readings are the same. If March water level measurements start to go down, then the aquifer is not being recharged as hoped.
Replenishment for the aquifer in the Columbia River Basalt may come in part from the Blue Mountains, according to George Chadwick, a water resources engineer based in La Grande. Although the basalt has low permeability vertically, which limits surface water from reaching the aquifer, because the basalt was laid down in volcanic layers, water tends to flow laterally along the layers. This lateral flow may allow water from the surrounding mountains to recharge the basalt aquifer.
“In general, there are a fair amount of unknowns,” Gall said.
The unknowns include the impact of drought cycles, the degree of recharge of water to the aquifer and rate at which recharge occurs.
Drilling Rudd’s basalt well may aid understanding of sub-surface water flows in the basin by helping geologists create a sub-surface map.
The drillers are taking samples every 10 feet, providing the state with a look into the type of sediment and rock down through the layers.
“It is a unique opportunity to get samples deep in the basin,” Gall said.
Geologists use chemistry in rocks — much like a geneticist would use DNA — to identify lava flows and create a subsurface map.
“There is a chemical fingerprint on individual lava flows,” said Jason McClaughry, Eastern Oregon regional geologist for Oregon Department of Geology and Mineral Industries. “If we can analyze the chemistry of another deep well, it refines the picture we get of subsurface geology.”
A subsurface map of the layers of basalt as well as data on which layers have water and what direction the water flows will help McClaughry, Gall and others create a Ground Water Flow Model.
The Ground Water Flow Model will help shape regulations for water use in the Grande Ronde Valley.