(C) Wisconsin Watch This story was originally published by Wisconsin Watch and is unaltered. . . . . . . . . . . Ripple Effects: Have 10 years of efforts made a difference in Iowa’s water quality? [1] ['Doapp', 'The Gazette', 'Alejandro Rojas', 'Erin Jordan', 'Eva Tesfaye', '- Wwno-New Orleans Public Radio', 'Emily Andersen', 'Tom Barton', 'Jared Strong', 'Iowa Capital Dispatch'] Date: 2024-06 The Gazette dove into ISU data to investigate how conservation practices and facility upgrades have impacted Iowa’s nitrogen and phosphorous pollution Prairie grasses blow in the wind Nov. 20 in a field near in northern Linn County. New conservation practices planned across the Middle Cedar River watershed will reduce an estimated 45 percent of nitrate in runoff from 1,200 acres of Linn County farmland. (Nick Rohlman/The Gazette) This is the first of a two-part series on 10 years of the Nutrient Reduction Strategy and its rippling impacts on Iowa’s water quality. Read part two here, and an explainer about the strategy here. More than 300,000 acres of farmland call Linn County home. Under many of the swaying cornfields and sprouting soybean crops, there’s a network of tile lines, pulling from the water table and spitting nutrient-rich drainage into nearby waterways. For decades, that pathway was untouched for most county farmland. That’s slowly changing. Within the next few months, 24 new saturated buffers will redirect agricultural drainage through soil and vegetation that suck nitrogen out. Thirteen bioreactors will force farm runoff through underground mounds of wood chips to filter out the nutrient. The practices — part of a “batch and build” initiative across the Middle Cedar River watershed — will reduce an estimated 45 percent of nitrate in runoff from 1,200 acres of Linn County farmland. Similar conservation actions are unfolding across Iowa — and have been since the Nutrient Reduction Strategy was finalized in 2013. The legislation drafted a plan for reducing Iowa’s nitrogen and phosphorous contributions to the Gulf of Mexico Hypoxic Zone — better known as the “dead zone” — spelling out stricter regulations for wastewater discharge and voluntary conservation measures for agriculture. The mission is crucial: Nutrient pollution plagues Iowa’s recreational opportunities, aquatic ecosystems and drinking water supplies, posing dangers to human and ecological health. “There is an immediate, urgent and serious set of implications for getting our nutrient management under control here in Iowa,” said David Cwiertny, director of the Center for Health Effects of Environmental Contamination at the University of Iowa. As 2023 — the 10th anniversary of the Nutrient Reduction Strategy — draws to a close, The Gazette is looking at Iowa’s progress. We dove into Iowa State University’s Nutrient Reduction Strategy data dashboards to answer the question: After a decade of work, is Iowa making strides toward its water quality goals? Edge-of-field practices making progress The conservation projects across the Middle Cedar River watershed comprise just a portion of Iowa’s headway in edge-of-field practices, or conservation efforts that reduce nutrient pollution from agricultural runoff. At least 107 bioreactors and 87 saturated buffers were installed throughout the state from 2011 to 2021. Together, they treat about 9,700 acres of drained cropland — about three times as big as the Los Angeles International Airport. The practices reduce an estimated 43 percent and 50 percent of nitrate pollution respectively. Wetlands also treat farm runoff, reducing about 52 percent of its nitrogen load. As of 2021, Iowa had 119 water quality wetlands that treated drainage from 139,000 acres, or about the size of Chicago. Some edge-of-field practices prevent soil-bound phosphorous from escaping to waterways via erosion. Those practices include terraces, water and sediment control basins and farm ponds. Since 2011, an estimated 290,000 Iowa acres have been protected by new erosion control practices. That’s about the size of Los Angeles or Phoenix. Contractor Caleb Svoboda digs a tile line in a field in northern Linn County on Monday, Nov. 20, 2023. (Nick Rohlman/The Gazette) Tile line sits in a saturated buffer under construction in a field in northern Linn County on Monday, Nov. 20, 2023. (Nick Rohlman/The Gazette) A saturated buffer under construction in a field in northern Linn County on Monday, Nov. 20, 2023. (Nick Rohlman/The Gazette) A tile line drains from a field in northern Linn County on Monday, Nov. 20, 2023. (Nick Rohlman/The Gazette) Dry Creek in northern Linn County on Monday, Nov. 20, 2023. (Nick Rohlman/The Gazette) Movement on edge-of-field practices has “taken off” thanks to batch and build projects, like the one in the Middle Cedar River watershed, said Jamie Benning, ISU’s assistant director for agriculture and natural resources extension. The watershed had 16 saturated buffers and bioreactors and 12 wetlands by 2021 — numbers that will grow with Linn County’s new additions. “While we still have a long way to go, like with a lot of practices, I think that has been a breakthrough with getting edge-of-field practices on the ground,” Benning said. “I encourage everyone to see where we were not too long ago and where we are now.” The swelling edge-of-field projects marks progress for Iowa. But their numbers only scratch the surface of the state’s 27 million-odd acres of row cropland. “If you look at the numbers of practices relative to the state, they're fairly insignificant,” said state geologist Keith Schilling. “I think that's been a real disconnect — by some not acknowledging the huge gap in practices versus improved water quality.” In-field practices coming up short Nutrient reduction can start with farming practices — from changing tilling methods to rotating crops, from retiring environmentally sensitive farmland to adjusting fertilizer application timing. Tilling practices have swayed further toward no-till and reduced tillage since the start of the Nutrient Reduction Strategy. As of 2021, farmers used no-till or strip-till on 9.5 million acres of crops — accounting for 41 percent of reported tilling practices. That’s up from 7 million acres in 2012. Conventional tillage, which makes soils more vulnerable to erosion and runoff, has fallen dramatically since the 1980s. In-field conservation tools also include cover crops, which are planted outside the growing season to prevent soil erosion, improve soil organic matter and retain nutrients leftover from harvest. Before 2010, there were very few acres of cover crops in Iowa. The 2017 Census of Agriculture reported 970,000 cover crop acres planted in Iowa that fall. The Survey of Agricultural Retailers estimated 2.8 million acres were planted in fall 2021 — protecting just under 10 percent of Iowa’s total row cropland. A field in northern Linn County on Monday, Nov. 20, 2023. (Nick Rohlman/The Gazette) A tile plow in a field in northern Linn County on Monday, Nov. 20, 2023. (Nick Rohlman/The Gazette) Farmland near Palo, Iowa on Wednesday, Nov. 8, 2023. (Nick Rohlman/The Gazette) Cover crops grow on Dan Voss’s land near Palo, Iowa on Wednesday, Nov. 8, 2023. Voss has implemented conservation practices on his land since the 1980s. (Nick Rohlman/The Gazette) Estimated nitrogen fertilizer and manure application on Iowa cropland has stayed relatively constant between 2012 and 2017. But recent fertilizer sales point to an increase since then — one faster than Iowa’s growth in corn acres. That suggests that the average rate of commercial nitrogen application has increased over time, according to the ISU data dashboards. Every drop of that fertilizer — especially its excess — is subjected to agriculture’s “leaky system” that leads to nutrient pollution, said Matt Helmers, director of ISU’s Nutrient Research Center. That’s why fertilizer application timing is also so important. Best practices are to apply nitrogen fertilizer and manure in the spring growing season, when plants need them most — which only about 13 percent of producers reported doing in 2021. For the second year in a row, Iowa farmers applied more commercial fertilizer this fall than in the spring, The Gazette previously reported, reversing an eight-year trend of more spring application. “That's an area that we are trying to do education around,” Helmers said. “Good nitrogen management is one that, if we can reduce some of the inputs and maintain our corn yield, could improve the profitability of the farmer.” Point sources making headway Coralville’s Wastewater Treatment Plant originally was built in 1969. Due to population growth — plus the requirements from the Nutrient Reduction Strategy — the city was forced to upgrade its aging plant. The resulting upgrades, completed in 2020 with a $32 million price tag, allow the facility to remove about 92 percent of the nitrogen and 71 percent of the phosphorous from its 2.6 million gallons of treated sewage each day. “The old plant did remove some nutrients, but it wasn't really designed to do that,” said wastewater department Superintendent David Clark. “The new facility is.” A life jacket hangs on a railing at the Coralville wastewater treatment plant, in Coralville, Iowa on Thursday, Nov. 16, 2023. The plant underwent a 2 year and $32 million upgrade process to better monitor and mitigate nutrient discharges. (Nick Rohlman/The Gazette) Pumps at the Coralville wastewater treatment plant, in Coralville, Iowa on Thursday, Nov. 16, 2023. The plant underwent a two-year and $32 million upgrade to better monitor and mitigate nutrient discharges. (Nick Rohlman/The Gazette) A control panel at the Coralville wastewater treatment plant, in Coralville, Iowa on Thursday, Nov. 16, 2023. The plant underwent a two-year and $32 million upgrade to better monitor and mitigate nutrient discharges. (Nick Rohlman/The Gazette) Nitrogen gas bubbles up from bacteria colonies as wastewater is treated at the Coralville wastewater treatment plant, in Coralville, Iowa on Thursday, Nov. 16, 2023. The plant underwent a two-year and $32 million upgrade to better monitor and mitigate nutrient discharges. (Nick Rohlman/The Gazette) Wastewater Department Superintendent David Clark explains the ultraviolet treatment process during a tour of the Coralville wastewater treatment plant, in Coralville, Iowa on Thursday, Nov. 16, 2023. The plant underwent a two-year and $32 million upgrade to better monitor and mitigate nutrient discharges. (Nick Rohlman/The Gazette) A clarifier at the Coralville wastewater treatment plant, in Coralville, Iowa on Thursday, Nov. 16, 2023. The plant underwent a 2 year and $32 million upgrade to better monitor and mitigate nutrient discharges. (Nick Rohlman/The Gazette) Water samples await testing at the Coralville wastewater treatment plant, in Coralville, Iowa on Thursday, Nov. 16, 2023. The plant underwent a 2 year and $32 million upgrade to better monitor and mitigate nutrient discharges. (Nick Rohlman/The Gazette) The Coralville Wastewater Treatment Plant is one of 161 municipal wastewater treatment plants and industrial facilities regulated under the Nutrient Reduction Strategy. Each are required to monitor their nitrogen and phosphorous discharges and develop feasibility studies for nutrient reduction improvements. Eventually, they receive new and enforceable nutrient discharge limits. At the end of 2021, 154 feasibility studies had been submitted. Forty-seven facilities had complied with their new nitrogen discharge limits. Twenty-three complied with their new phosphorous targets. “The good news is we're seeing good steady progress of our point sources beginning to meet these targets,” said Adam Schnieders, the Iowa Department of Natural Resources water quality resource coordinator. ISU measured the impact on point source nutrient pollution so far. Between 2019 and 2021 — as facility upgrades ramped up — nitrogen loads from the regulated facilities dropped nearly 8 percent, and phosphorous loads dropped about 12 percent. “Hopefully, once everyone gets there, we can knock (pollution) down to meet those target lines for total phosphorus and total nitrogen for point sources,” Schnieders said. “That's where we're headed.” In the meantime, facilities are boosting their nutrient monitoring efforts. Point sources went from zero samples for monitoring to about 32,000 nitrogen and phosphorous samples annually — about a $1.1 million investment. “The amount of information that we're able to access and collect, and then analyze and how that informs policy moving forward … It’s awesome,” Schnieders said. “We've never had that before.” How does it translate to water quality? Land use changes, agricultural conservation practices and point source upgrades all factor into the ultimate goal of the Nutrient Reduction Strategy: a reduction in nitrate and phosphorous loads in Iowa waterways — the measurable mark of progress. ISU modeled the impact of certain land use and conservation practices on nutrient loads to calculate if Iowa is moving in the right direction, Benning said. The reported amount of cover crop acres, for instance, helps reduce nitrogen pollution by 12,015 tons. Timing changes for fertilizer and manure application cut it by 7,872 tons. All of the reductions, though, are dwarfed by the nitrate pollution contributed by Iowa’s dominant land use: row crops that are not using nitrate reduction practices. Corn and soybeans alone add 32,229 tons to the state’s nitrogen load. Those modeled impacts are reflected in the nitrogen loads physically sampled in the waterways flowing out of Iowa, which have been normalized to annual stream flow to smooth out the influence of rainfall or drought. In 2012 before the nutrient strategy was implemented, the five-year average flow-weighted nitrate load was at 22,700 tons per inch of flow. In 2021, it was at 22,900 tons. “We need a 45 percent reduction, and we're essentially not even at where we were the year before all this started,” Cwiertny said. “From a water quality perspective, we're not seeing the gains that we need to be making to make meaningful progress towards those goals.” The state’s modeled progress on phosphorous loads is more encouraging. The impact of no-till alone decreases phosphorous pollution by nearly 4,000 tons. Cover crops prevent another 2,000 tons from entering waterways — overshadowing the 826 tons contributed from pasture, grass and hay that have been decreasing in acreage since the 1980s. The physically measured five-year average phosphorous load — again, normalized to annual stream flow — has remained relatively stable, at 1,800 tons per inch of flow in both 2012 and 2021. But up to half of that phosphorous may be coming from nutrients trapped in stream beds and banks that are now eroding away — the lasting legacy of decades of conventional farming. “At least for the phosphorous portion, we have been doing a good job in Iowa, even before the Nutrient Reduction Strategy, and that shows,” said Antonio Mallarino, an ISU agronomy professor who helped develop the Iowa Phosphorus Index. “But it also shows that we need to keep working on our reach and extension so farmers really implement some of the best practices.” Brittney J. Miller is the Energy & Environment Reporter for The Gazette and a corps member with Report for America, a national service program that places journalists in local newsrooms to report on under-covered issues. Comments: (319) 398-8370; brittney.miller@thegazette.com [END] --- [1] Url: https://www.thegazette.com/environment-nature/ripple-effects-have-10-years-of-efforts-made-a-difference-in-iowas-water-quality/ Published and (C) by Wisconsin Watch Content appears here under this condition or license: Creative Commons BY-ND 4.0 Intl. via Magical.Fish Gopher News Feeds: gopher://magical.fish/1/feeds/news/wisconsinwatch/