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Nutrient pollution: a persistent threat to waterways.

Manuel J - Environ. Health Perspect. (2014)

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Passage of the Clean Water Act of 1972 brought many improvements to surface waters by curbing much of the toxic and organic pollution going into waterways... But 42 years later, we have yet to make significant reductions in two major pollutants in our rivers, lakes, and coastal sounds—the nutrients nitrogen and phosphorus... Local water treatment plants may not have the equipment necessary to rid drinking water of these toxins... In that case, the only safe course of action is to find other sources of drinking water for however long the toxin persists in the water supply, as was demonstrated in August 2014, when hundreds of thousands of Toledo residents found themselves without potable water... Although relative amounts vary from watershed to watershed, the fertilizer and animal waste that leach off farmed land generally contribute the most nonpoint-source nutrient pollution to U.S. waterways... However, phosphorus and nitrogen are not among the regulated chemicals... Furthermore, the law does not include regulation of nonpoint-source pollution... Section 303(d) of the Clean Water Act does require states to submit a list of impaired and threatened waters within their jurisdiction and establish priorities for the development of total maximum daily loads (TMDLs) of pollutants for these water bodies... TMDLs are not the only vehicle being used to address nutrient pollution... The EPA awards grants to states to build or upgrade wastewater treatment plants and to support various state-level nonpoint-source management programs... Various best management practices (BMPs) are being employed to reduce nutrient pollution from urban sources... When [government] subsidies pay less than cash rent, the conservation practices disappear. ” Nutrient trading between point and nonpoint sources is an idea that is promoted as an alternative to cost-sharing... In this voluntary system, farmers accumulate and sell credits by implementing conservation measures that reduce nutrient loads... Further, nutrient trading programs can be complex, and they take time to establish. “There is a lot of both hope and frustration [among farmers] with nutrient trading,” says John Bell, government affairs counsel for the Pennsylvania Farm Bureau. “Pennsylvania set a reasonable set of ground rules for nutrient trading, but even with this, it’s hard for farmers to get enthusiastic because of the limited credit given to their conservation practices. ” He explains that a farmer may implement a practice that reduces a hundred pounds of nitrogen at the stream flowing past his farm, but will only receive nutrient trading credit for the impact that action has in waters possibly hundreds of miles away. “Very few practices to reduce nonpoint-source pollution have an immediate impact on a watershed,” he says. “Often, the impacts are not measurable for a number of years after the [practice] was first implemented. ” Some experts believe that without setting numeric water-quality standards for nitrogen and phosphorus, efforts to combat nutrient pollution will fail.

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Phosphorus Pollution in U.S. Rivers and StreamsIn eight of the nine ecoregions defined by the EPA, phosphorus levels are consistently rated poor (i.e., high) in at least a third of river and stream miles. The Northern Plains and the Northern Appalachians have the highest proportions of miles rated poor (84% and 71%, respectively). The Southern Plains ecoregion has the highest percentage of river and stream miles rated good (50%), with only 23% rated poor for phosphorus levels.Source: EPA.1 Percents may not add up to 100% due to rounding.
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d35e149: Phosphorus Pollution in U.S. Rivers and StreamsIn eight of the nine ecoregions defined by the EPA, phosphorus levels are consistently rated poor (i.e., high) in at least a third of river and stream miles. The Northern Plains and the Northern Appalachians have the highest proportions of miles rated poor (84% and 71%, respectively). The Southern Plains ecoregion has the highest percentage of river and stream miles rated good (50%), with only 23% rated poor for phosphorus levels.Source: EPA.1 Percents may not add up to 100% due to rounding.


Nutrient pollution: a persistent threat to waterways.

Manuel J - Environ. Health Perspect. (2014)

Phosphorus Pollution in U.S. Rivers and StreamsIn eight of the nine ecoregions defined by the EPA, phosphorus levels are consistently rated poor (i.e., high) in at least a third of river and stream miles. The Northern Plains and the Northern Appalachians have the highest proportions of miles rated poor (84% and 71%, respectively). The Southern Plains ecoregion has the highest percentage of river and stream miles rated good (50%), with only 23% rated poor for phosphorus levels.Source: EPA.1 Percents may not add up to 100% due to rounding.
© Copyright Policy - public-domain
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4216153&req=5

d35e149: Phosphorus Pollution in U.S. Rivers and StreamsIn eight of the nine ecoregions defined by the EPA, phosphorus levels are consistently rated poor (i.e., high) in at least a third of river and stream miles. The Northern Plains and the Northern Appalachians have the highest proportions of miles rated poor (84% and 71%, respectively). The Southern Plains ecoregion has the highest percentage of river and stream miles rated good (50%), with only 23% rated poor for phosphorus levels.Source: EPA.1 Percents may not add up to 100% due to rounding.

View Article: PubMed Central - PubMed

AUTOMATICALLY GENERATED EXCERPT
Please rate it.

Passage of the Clean Water Act of 1972 brought many improvements to surface waters by curbing much of the toxic and organic pollution going into waterways... But 42 years later, we have yet to make significant reductions in two major pollutants in our rivers, lakes, and coastal sounds—the nutrients nitrogen and phosphorus... Local water treatment plants may not have the equipment necessary to rid drinking water of these toxins... In that case, the only safe course of action is to find other sources of drinking water for however long the toxin persists in the water supply, as was demonstrated in August 2014, when hundreds of thousands of Toledo residents found themselves without potable water... Although relative amounts vary from watershed to watershed, the fertilizer and animal waste that leach off farmed land generally contribute the most nonpoint-source nutrient pollution to U.S. waterways... However, phosphorus and nitrogen are not among the regulated chemicals... Furthermore, the law does not include regulation of nonpoint-source pollution... Section 303(d) of the Clean Water Act does require states to submit a list of impaired and threatened waters within their jurisdiction and establish priorities for the development of total maximum daily loads (TMDLs) of pollutants for these water bodies... TMDLs are not the only vehicle being used to address nutrient pollution... The EPA awards grants to states to build or upgrade wastewater treatment plants and to support various state-level nonpoint-source management programs... Various best management practices (BMPs) are being employed to reduce nutrient pollution from urban sources... When [government] subsidies pay less than cash rent, the conservation practices disappear. ” Nutrient trading between point and nonpoint sources is an idea that is promoted as an alternative to cost-sharing... In this voluntary system, farmers accumulate and sell credits by implementing conservation measures that reduce nutrient loads... Further, nutrient trading programs can be complex, and they take time to establish. “There is a lot of both hope and frustration [among farmers] with nutrient trading,” says John Bell, government affairs counsel for the Pennsylvania Farm Bureau. “Pennsylvania set a reasonable set of ground rules for nutrient trading, but even with this, it’s hard for farmers to get enthusiastic because of the limited credit given to their conservation practices. ” He explains that a farmer may implement a practice that reduces a hundred pounds of nitrogen at the stream flowing past his farm, but will only receive nutrient trading credit for the impact that action has in waters possibly hundreds of miles away. “Very few practices to reduce nonpoint-source pollution have an immediate impact on a watershed,” he says. “Often, the impacts are not measurable for a number of years after the [practice] was first implemented. ” Some experts believe that without setting numeric water-quality standards for nitrogen and phosphorus, efforts to combat nutrient pollution will fail.

Show MeSH