River Study To Impact Region's Growth

A study on the Illinois River's watershed will help determine where and how developers should build, farmers fertilize and engineers locate roads in Northwest Arkansas for decades to come.

"There could not be anything bigger environmentally than the ramifications of the results of that study," said Tom Hopper, chairman of Crafton Tull. The Rogers-based company is one of the region's largest engineering and architectural consulting firms.

Northwest Arkansas' largest cities sit on a plateau made up in part of eroded, channeled limestone underneath a layer of clay and soil, Hopper said. Water draining from that plateau ends up in either the Illinois River watershed to the west or, to a lesser extent, the White River basin in the east. A portion of rainwater after storms goes into an underground environment and becomes "groundwater," he said.

Protecting the Illinois River's watershed has steered decisions on development, farm management, city drainage and road construction for decades during the region's rapid growth, Hopper said.

Arkansas and Oklahoma commissioned the two-year study by Ryan S. King, an aquatic biologist at Baylor University, as a solution to ongoing legal disputes over the river. The Illinois is a protected scenic river in Oklahoma.

Disputes arose between Arkansas and Oklahoma when researchers found that cloudiness in the river and Lake Tenkiller in Oklahoma was caused by a rise in phosphorus levels. The phosphorus fed undesired algae, causing the murk. This was the most visible of phosphorus' undesired effects, which included risks to wildlife in the river.

Oklahoma's efforts to impose phosphorus standards on Arkansas city wastewater treatment plants went all the way to the U.S. Supreme Court in 1992. The court ruled Oklahoma can set limits for rivers that a bordering state's cities have to meet.

"Wastewater plants are the most obvious targets" for controlling phosphorus, said Don Marr, chief of staff for the city of Fayetteville. "They require permits, and those permits can be challenged in court."

A 2005 lawsuit brought by the attorney general of Oklahoma against Arkansas poultry companies over chicken litter used for fertilizer has languished in federal court. The suit contends runoff from the phosphorus-rich fertilizer is polluting the river. The trial ended Feb. 18, 2010, but the judge has yet to rule on the case.

Finding The Limit

The two states dispute what is a safe limit on the amount of phosphorus the river's environment can withstand. The study agreement was reached after Oklahoma adopted a proposed limit of 0.037 milligrams per liter and Arkansas protested.

King's study will determine the limit. Once the study concludes in 2016, both states are bound by their agreement to do whatever it takes to keep the river within that limit. That includes a commitment to reduce the phosphorus level if needed.

How the people in each state stay within the phosphorus limit is not a subject of the study, said Derek Smithee, chief of the water quality programs division on the Oklahoma Water Resources Board. Smithee was one of the three members from Oklahoma who were appointed to the six-member board overseeing the study. The other three came from Arkansas, and together they agreed unanimously upon King.

"He's going to find what amounts to a speed limit," Smithee said. "He's not going to tell us how the phosphorus got there or assign blame. He's going to find a number and say, 'This much phosphorus and no more.'

"What we do after we know that limit will be a lot like losing weight. You can diet or you can exercise, or you can diet less and exercise more or diet more and exercise less," he said.

"We're not totally blind to the source, but that's not the subject of the study, so we're pretty blind to it," Smithee said. "If we can stay within the limit by sprinkling pixie dust, that's fine with us."

Defensible Results

The study is one of the most intensive of its kind in the United States, King said.

"We have picked 35 sites and will be testing each of them at a very high frequency -- every other month," he said. "This is intense enough that when we're done, we're going to have a scientifically defensible number, one that stands up," King said.

The testing extends far beyond water samples. For instance, well-regarded specialists will examine algae samples. Not all algae is the same, and microscopic examination in a laboratory is needed to confirm the difference, he said.

Some nuisance types of algae can only grow in high-phosphorus areas.

"Some are phosphorus hogs," he said. "Those types use a lot more phosphorus than others, and grow once the level of phosphorus gets above a certain level." So samples of phosphorus in the water downstream may not show how much phosphorus was there before that algae grew.

The thickness and extent of algae, calculating the algae's "biomass" and determining exactly what type it is can provide a better record of what phosphorus levels are day in, day out than random water sampling alone, he said. Even a thin film of algae can amount to a serious amount if it is spread widely enough, he said.

Waters with various depths, flows and underwater surfaces will be tested, King said. Samples of aquatic insects, crayfish, fish and snails will be taken and estimates made of the density of those populations. "Snails are prolific grazers of algae," King said, so more algae may have grown in a sample area than is left to meet the eye. "In some places, the snails are so thick it's like walking on popcorn," he said.

Rapid Runoff

Enough research was done before King's study, here and elsewhere, to show that storm water runoff from cities is a major factor in phosphorus levels, Delia Haak said. She's executive director of the nonprofit Illinois River Watershed Partnership, which encourages protection of the watershed.

"Storm water is the nation's No. 1 pollutant," Haak said. Storm water carries phosphorus and other chemicals washed off driveways, roofs and parking lots. Traditional curb-and-gutter city drainage systems carry storm water away rapidly. That channeled rush of water washes more phosphorus away from other sources downstream, such as streams running through pastures and fields, she said.

It will likely take more than improved sewer plants to control phosphorus in the river, Marr said. If there are other, more cost-effective ways to control phosphorus, cities will ask why they should go to greater lengths and costs to solve the whole problem just by purifying wastewater, a portion of the problem.

"It's possible that there could still be a problem even if the amount of phosphorus released from treatment plants was reduced to zero," Marr said.

"If we're talking now about storm water runoff instead of treated wastewater, we're talking about billions, not millions, of dollars, to meet that standard," Marr said.

Billions of dollars were going to be spent on new curbs and gutters anyway as the cities in the region grew, said Haak said. Better options exist. Those alternatives will add no costs to developers if adopted widely, while sparing cities expensive new drainage control measures, she said.

"The site of the Sam's Club in Fayetteville doesn't have any more storm water runoff from it than it did when it was a vacant lot," Haak said. "They have (spaces) in their parking lots for trees and cisterns in the back that store runoff from the roof that they then use to water their landscaping."

Despite rapid development in the past, there's time to control runoff, she said.

"Half of what will be here in 50 years hasn't been built yet," she said. "Even downtown, built-up areas are often renovated and restored. We can do this."

"The history of flood control for cities is to get the water out of town as quickly as you can," Haak said. The alternative is to retain more of that water longer while not creating new problems, such as habitats for mosquitoes, she said.

Smithee agreed.

"Any time you put concrete down, you increase the water on other areas," he said. "That water has energy and will carry things with it. If you live in a house or build a business, all of those things have an impact on the aquatic environment. All of those elements need to be at the table. That's in Oklahoma, Arkansas -- or Maine."

Other Factors

Another factor in phosphorus levels will be loss of forest cover along the river, Haak said. How much phosphorus the river can abide depends on how much sunlight falls upon the water, which increases algae growth. Development in Northwest Arkansas removed trees and shade along the banks, she said.

This loss of cover and other factors mean the amount of phosphorus the river's environment can withstand has changed to an unknown degree, Smithee said.

Phosphorus levels in the river have gone down in recent years, monitoring by both Arkansas and Oklahoma show. Smithee and others credit runoff control efforts by farmers who adopted "best management practices" to control runoff and for applying litter as fertilizer. Other efforts to reduce phosphorus include an ongoing practice by poultry companies and both states that ships more than 100,000 tons of poultry litter a year out of the river's watershed for use as fertilizer elsewhere.

Below The Surface

Developers need to build more densely on land west of the region's urban centers for the area to continue its fast growth, said Jeff Hawkins, executive director of the Northwest Arkansas Regional Planning Commission. Much of the rain falling on that land goes directly into an underground environment that is home to an endangered species of gray bats and a threatened species of fish, among other life, he and Hopper said. The large eastward bend in I-49 between Bentonville and Springdale was built to avoid this underground environment's "recharge" zone for water.

"Up to now, we've just avoided it," Hawkins said of the area. "We can't do that anymore and keep growing."

The regional planning commission ordered a study by Crafton Tull to map water flows in the recharge area. The firm is expected to present its findings by April. Crafton Tull's work isn't part of King's study. A detailed understanding of the water flow in the area will allow development to proceed in a manner that will not disrupt the underground environment, Hopper said.

Best management practices for stormwater, such as a basic change in how cities manage flood control and drainage, will also be needed to protect the recharge area, Haak said.