Mont. team tackles saline seep pollution
CONRAD, Mont. — Farmers west of the Missouri River should be on the watch for saline seep problems, especially with increased rainfall and changes associated with the decline of the Conservation Reserve Program.
Saline seeps are damaging nonpoint source pollution problems that result in groundwater, surface water and soil contamination. High water tables remove salts from bedrock sources, lifting them to the surface. When the water evaporates, the salts are deposited, making the soil unproductive until the salts are leached back when the water table subsides.
“Some saline seeps that had been repaired in the past will now recur,” says Jane Holzer, program director for the Montana Salinity Control Association. Created in 1979, the association is located in Conrad, Mont., about 60 miles north of Great Falls. It is an entity of the Montana Association of Conservation Districts.
The project was created to take saline seep research from the universities and government and apply it to individual cases for reclamation. In the 1980s, the state estimated it had more than 300,000 acres of formerly productive cropland out of production because of saline seeps. No recent figures are available, Holzer says.
Since 1980, the team — three technical and two support staff — has worked with more than 1,000 landowners and projects. It has worked on 18 watersheds (2,000 to 600,000 acres) using funds from the Non-point Source Pollution Program, which originated from the U.S. Environmental Protection Agency.
Into the Dakotas
Wade Bott, a state soil scientist with the Natural Resources Conservation Service in Bismarck, says the majority of concern areas in North Dakota are west of the Missouri River in the sedimentary plains. It’s the same situation in South Dakota.
“Typically, it’s an area where you get water perking down in a recharge area, above where the seep is,” Bott says. “That hits a less permeable layer and the water will move laterally rather than vertically. When it hits the edge of a hill, the water picks up salts from the parent material. That raises the electrical conductivity of the soil — a soil property we use to measure the level of salinity.” That can make it difficult to establish any plants, including crops.
He says Dunn, Stark, Slope, Bowman, Adams and Grant counties have problems with the seeps, and it’s thought that more than 5 percent of the land area — or one in 20 acres — is affected by seep salts. He says some farmers try drainage tile to solve the problem, which isn’t likely to work.
Many farmers are very knowledgeable about their seep problems, but some don’t know all the facts. “If they’re treating the visual scar on the ground, then they’re not likely aware of how that was caused through the management practices,” Bott says.
Jay Fuhrer, an NRCS district conservationist in Bismarck for Burleigh County, says he doesn’t expect to see much of the saline seep issue east of the Missouri River, in part because of more continuous rotations of crops that grow every year and use the moisture.
“I don’t foresee anything on the scale of Montana’s problem. Even when this area used summer fallow extensively, we never had the saline seeps Montana had.”
Seep problems don’t respect landowner boundaries and require scientific diagnosis, Holzer says. Seeps are particularly a problem in north-central Montana, where some farmers use crop-fallow programs. If the fallow land accumulates more water than the subsequent crop can use before it percolates deeper into the soil profile, saline seeps become possible.
One landowner may have a seep problem that puts harmful salts on his land because of an underground water flow off a bedrock beneath the surface on a neighbor’s land, which may have no visual surface water problem at all.
“That’s the main reason we went to watershed projects,” Holzer says. “You have no reason other than the good of your heart, but if we can prove that you’re a recharge area, you can become eligible for a cost-share. That’s why an incentive helps on a recharge area.” A recharge area flows out to the saline seep or to a discharge.
Watershed-wide projects are typically grant-funded so individual farmers don’t have to pay for the thorough groundwater flow studies that are needed.
On individual projects, landowners can compete for federal cost-share through the Environmental Quality Incentive Program. EQIP pays for a portion of the groundwater investigation, a portion of the seed and seeding, which costs about $35 to $45 an acre. The agency will handle 75 to 100 percent of the cost to get a recharge area — which flows out to the saline seep or to a discharge — forage established.
The state of Montana gives baseline funding to projects, and landowners pay a cost-share — $3,000 to $4,000 — to operate a project. A typical project might be a quarter-section of land, serving a grid of eight to 15 wells, depending on topography.
For three years, the landowner also receives an annual payment.
“We don’t call it an incentive payment anymore but ‘income foregone,’” Holzer says. “There is a transition from going from cereal grain to hay. You can lose a whole year’s income because there’s no hay off that first year.”
Funds were formerly for five years, but now only run three years. To achieve the groundwater trend, the land has to stay in the alfalfa or a perennial for at least five years. Some leave it 10 years.
No haying equipment
Holzer says the CRP that started in 1985 has been a great tool to address salinity because it gave producers the economic ability to convert broad acres to perennial crops. CRP contracts have been expiring in larger numbers, which likely will cause saline problems to increase or recur.
One of the problems today is that some landowners have no haying equipment and no livestock to use forages.
“In that case, the CRP was a natural tool,” Holzer says. “Now they would have to manage it in some way.
“We’re encouraging people to be judicious as they take land out of CRP,” Holzer says. “Anything that they know was saline at one time, why don’t they leave that perennial forage on that spot? It might be 10 percent of the total acreage they have and consider it a cost of business that can prevent a saline seep from coming back as fast.”
It’s tricky because sometimes the groundwater levels are not the same as the surface topography. Holzer says it’s more important to conduct a study on rolling or flat land.
Researchers install shallow monitoring wells in a grid system and measure depths of the water table to determine groundwater flows and directions. From that, they identify the higher elevation recharge area.
“We learned a long time ago that it’s futile to only address the saline area — to try to grow something there or try to tile drain it. It doesn’t fix the problem,” Holzer says. “Instead of treating the symptom, you treat the problem, which primarily in Montana was in dryland (nonirrigated) and it was a crop-fallow system.”
The crop-fallow system
In the 1980s, many farmers changed from crop-fallow to a more intensive cropping system, which reduced some of the problems.
There is little summer-fallow in northeast Montana counties now, where recent increased precipitation has allowed re-cropping. Farmers there were heavier in spring wheat and durum and alternative crops such as field peas, lentils and chickpeas.
The Golden Triangle from Glacier east to Havre and south to Great Falls, is a different story. This area originally was primarily winter wheat and fallow, and then more barley came in. Farmers often intermittently use alternative crops or fallow rotations. In the past 10 years, there hasn’t been enough rainfall to re-crop every year, so many more farmers have gone to spring wheat or barley in one year, followed by a fallow and the fall seeding of winter wheat.
“If you think of a 24-month crop-fallow period, if you’re growing only a spring wheat crop or durum, out of that 24 months you only have something actively growing for three months, when the roots are using soil moisture,” Holzer says. “In the other 21 months, you receive more moisture than you can store in the rooting zone. That moisture that leaches below into the rooting zone becomes the recharge.”
Initially, the Montana Salinity Control Association used perennial forage plantings in the so-called recharge area — an area of underground shale. The perennials tend to use all of the precipitation and dry out the deep subsoil moisture in the seep area.
Alfalfa can root 20 to 25 feet deep, depending on the variety. “You can dry out the soil to that depth and then have a reservoir of dry soil to store moisture in the future when you rotate away from the perennial forage and back to an annual cropping system,” Holzer says. “We encourage people to re-crop as economically feasible and to use alternative crops, and not always be in a wheat-fallow, wheat-fallow system.
“All you need to do is lower the water table,” Holzer says. “Natural precipitation will leach those salts back down to wherever the water table has been stabilized. We like to see that 7 feet below the surface. A saline seep is where the water is typically within 3 feet of the surface. Then you get that capillary action, which pulls water to the surface. It evaporates and leaves the salt. Over time, the salt accumulates and it can create a thick salt crust.”
Tiling: a short-term fix
In the 1970s, the Soil Conservation Service cost-shared tile drainage costs in saline seeps. That ended because of concerns about passing along water quality problems.
In Alberta and Saskatchewan, farmers drained for years after it was no longer allowed in Montana, Holzer says. In the past, it was cost-prohibitive to space tiles closely enough to have any impact.
“That was when land was $400 an acre,” Holzer says. “When it’s higher-priced, it’s a different situation. But even then, tile drainage doesn’t solve the problem. It just transfers it to your neighbor.”
In Montana, very little tile drainage is done, in part because, by law, effluent must be as good or better than the state water it gets flushed into.
“Any creek, any waterway, any groundwater is owned by the state,” Holzer says. “You can’t put your saline water into a state water system. Basically, drainage has not been used in (nonirrigated) dryland. First of all, it’s not cost-shared and second, it doesn’t solve the problem.”
Most of the team’s work is with nonirrigated ground. “We do work with irrigated land, but the cure is totally different than what you do for dryland, normally,” Holzer says.
“In either case, you try to lower the groundwater. In dryland, the crop-fallow system has caused a high water level. So we want to reverse that with deep-rooted perennial crops in the recharge area. That’s different than if you’re out on an irrigated flat with a water table 4 or 5 feet (below the surface) and there’s really nothing an individual can do to lower it himself with cropping.”
Holzer says tile drainage in a seep area is a short-term fix — five to 20 years. Individually, water coming out of a problem may not be poor quality, but cumulatively, tile drainage passes on salts that have to go somewhere. As the water evaporates, it leaves salts. The same is true for nutrients, including nitrates.
“In Montana, they would not be allowed to do the tile draining, and it’s from a water quality standpoint,” Holzer says. And salts are the biggest quality issue.