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December 6th - Big Sioux River Water Summit - 1:00PM to 5:00PM at the Downtown Hilton Garden Inn (Sioux Falls)
December 19th – 10:00 AM – South Dakota Non-point Source Task Force, Matthews Training Center, Joe Foss Building, Pierre
December 20th – 1:00 PM EDWDD Board Meeting, EDWDD Office 132 B Airport Avenue, Brookings
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We Build Successful Relationships. With a 130-year commitment to our communities, and a foundation built on our FIRST Values, we pride ourselves on being more than just a bank. We do things differently. We have locations in Brandon, Baltic, Dell Rapids, Flandreau, Harrisburg, and 12 Sioux Falls locations to serve you
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Nitrates: What Do You Need to Know?
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Nitrate pollution is increasing in our watershed. Unfortunately, the DENR has chosen to overlook the nitrate pollution from large plants and cities who discharge nitrate loaded wastewater into the Big Sioux. This newsletter is devoted to exploring the beneficial uses, sources, and problems posed by nitrates. Next month, we will continue our efforts to increase awareness of nitrate use, benefits, threats, and what actions need to be taken to protect our water from further contamination.
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What are Nitrates?
Nitrates are a part of nature—occurring naturally in safe quantities. However, the manufacture and applications of synthetic nitrates can be cause for concern. Nitrates come in many forms from potassium nitrate to sodium nitrate. Most inorganic nitrate salts are water soluble, and their high solubility make them a versatile compound. In its many diverse forms, nitrates can be used for:
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- Fertilizers – Several nitrate salts, including ammonium, sodium, potassium, and calcium, are great for aiding plant growth and crop yields.
- Explosives – Nitrates can be used in explosives and are a key component of gunpowder.
- Food Preservatives – Not to be confused with nitrites, nitrates can be used in specialty curing processes and in packaged meats.
- Methamphetamines – Ammonium nitrate can be used in the manufacturing of methamphetamines.
- Cold Packs – Nitrates can be used in instant cold packs.
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How are Nitrates Produced?
Nitrates can result from several processes, both natural and artificial. Processes include:
- Biological Fixation – This is a natural process wherein atmospheric nitrogen falls to earth in precipitation. Through a series of processes, this nitrogen is converted by plant roots and soil bacteria to nitrates which plants can take up. Some plants, such as soybeans, and certain microorganism, such as cyanobacteria, remove nitrogen from the air and infuse it into the soil.
- Industrial Production – To make nitrates for artificial fertilizers, high temperatures and high pressures are used to create a reaction that produces nitrates. These types of synthetic nitrates are the focus of our concern.
- Wastewater Treatment - When wastewater is treated, the bacteria that help process the water convert any ammonia present in the water to nitrates. Currently, the wastewater treatment plants along the Big Sioux River are allowed to release a high level of nitrates into the river.
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How Do Nitrates End Up in Our Water?
The production and subsequent use of synthetic nitrates can lead to excessive nitrate levels in our ecosystem. Through the combination of non-point source runoff and point source discharge, nitrates find their way into local waterways and shallow aquifers, which can threaten water safety. Nitrate pollution results from:
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- Wastewater Treatment Facilities – When municipalities and many manufacturing plants treat their wastewater, nitrates are a frequent byproduct. The level of nitrates allowed in discharge water in South Dakota is loosely regulated, and excessive nitrates can be discharged directly into local waterways.
- Agricultural Operations - Nitrate fertilizer from surface water runoff, tile drainage, and animal feces in the water can lead to nitrate pollution. When nitrate fertilizers are applied to fields, excess nitrates that are not absorbed by the plants enter lakes and streams from surface runoff or percolate into streams and aquifers from agricultural drain tiles.
- Food Processing Facilities – Meat packing and cheese plants often release high levels of nitrates in their wastewaters.
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Why Should We be Concerned with Nitrate Pollution?
Nitrate pollution is a major concern and has been linked to:
- Health Concerns - Nitrates in drinking water have been linked to Blue Baby Syndrome and are linked to a variety of cancers among the elderly. This will be the focus of our next issue.
- Algae Growth & Dead Zones - Nitrates help facilitate plant growth, which is why they make for great fertilizers. However, the same chemical that makes plants grow also spurs algae growth. Excess algae caused by nitrates (and phosphorus) lowers oxygen levels in water, resulting in hypoxic dead zones. This lack of oxygen causes fish and other aquatic life to suffocate and die. Nitrate pollution from farms and cities in the Midwest drains to the Gulf of Mexico, causing a dead zone to develop equal in size to 1/8th of South Dakota's total farmland! Scientists believe that even if 100% of nitrate pollution ended today, it may take thirty years for the dead zone to recover. Ending total nitrate use isn't sustainable, so stricter limits on all nitrate runoff and discharges are needed to limit the growth of these dead zones.
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What are Safe Nitrate Levels?
The EPA says nitrates levels are too high for drinking water when they reach 10 parts per million (PPM). In South Dakota, nitrate levels are set at 50PPM in sections of waterways not designated as drinking water sources. Unfortunately, the higher nitrate concentrations in some parts of the river can influence downstream water quality in areas that may be designated as a drinking water source.
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Who is Impacted by Nitrate Pollution?
Everyone and everything in the watershed is impacted by nitrate pollution. Large hypoxic zones lead to major fish kills. Those whose livelihoods are connected to clean water, such as commercial fishermen, stand to lose everything. People who reside in rural areas are particularly vulnerable to nitrate pollution. A recent USGS fact sheet identifies rural domestic wells in areas where nitrogen-based fertilizers are used as most at risk of nitrate contamination. The same document states that nitrogen-based fertilizers contaminate shallow groundwater aquifers often used for public and private drinking water. On a local basis, landowners in southwest Minnesota and northwest Iowa, report unsafe nitrate levels in their wells.
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Many local communities have turned to projects like Lewis & Clark to provide ample safe drinking water. Allowing the contamination of local water sources is not a safe practice for urban or rural South Dakotan’s nor is it sustainable. We need to protect local water sources like the Big Sioux River and its aquifer to ensure that all communities and residents have safe local drinking water for today and the future.
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How Can Safe Nitrate Levels be Achieved?
Lower nitrate levels in local water can be achieved with the following common-sense practices:
- Install Vegetated Buffers – Buffers along waterways catch and absorb excess nitrates from surface runoff. Grasses in buffer strips use the nitrates to grow, keeping the excess chemicals from reaching our rivers, lakes, and aquifers.
- Limit Tile Drainage – Discharge from tile drains, which increase nitrate fertilizer runoff from fields, should be filtered through a nitrate sink, such as a grass buffer. These sinks can catch excessive nitrates and prevent them from flowing freely into our surface waters.
- Implement Denitrification at Water Treatment Facilities – As more industry comes to our state, businesses and municipalities should update their waste treatment facilities, ensuring that nitrate removal is a part of their operations which can help prevent costly health and environmental impacts.
- Review & Enforce Permits – Restrictions are only effective if enforced. Nitrate levels can be kept at a safe level if businesses are given clearly delineated parameters to abide by and if regulatory agencies enforce these limits. Discharge permits should be updated regularly to reflect new scientific research on nitrate use, combined with local factors of population growth and economic development.
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