14 DAY TRIAL // According to the results of a new study conducted by experts at the US Geological Survey (USGS), it would appear that streams and aquifers in the country are in very poor condition.
The new document cross-referenced nitrogen and phosphorus levels measured in 2010 with the ones measured in the early, and determined that the two chemicals have endured at the same concentrations.
In some places, there are now elevated levels of the two nutrients in streams and aquifers, which means that the situation got worst in the past two decades.
The two chemicals the USGS accounted for can impact aquatic ecosystems significantly, causing damage that would take years to recover from. Once they accumulate in fish, they pose a danger to human health as well.
“This USGS report provides the most comprehensive national-scale assessment to date of nitrogen and phosphorus in our streams and groundwater,” explains the director of the USGS, Marcia McNutt.
“For years we have known that these same nutrients in high concentrations have resulted in ‘dead zones’ when they reach our estuaries, such as during the spring at the mouth of the Mississippi, and now we have improved science-based explanations of when, where, and how elevated concentrations reach our streams and aquifers and affect aquatic life and the quality of our drinking water,” she adds.
Previous investigations conducted by the US Environmental Protection Agency (EPA) have revealed that nutrient pollutions is one of the three largest sources of threat for US streams and aquifers.
The situation is not new. Experts who have been in this field of research for a long time say that this have been happening for decades.
“Despite major Federal, State and local efforts and expenditures to control sources and movement of nutrients within our Nation’s watersheds, national-scale progress was not evident in this assessment, which is based on thousands of measurements and hundreds of studies across the country from the 1990’s and early 2000’s,” adds Matthew C. Larsen.
The expert is the USGS Associate Director for Water. He adds that the new research found phosphorus and nitrogern levels to be two to ten times greater than the maximum allowed limit.
Scientists explain that, when too much nutrients make their way into the water, the promote the growth of algae and other organisms, that are very invasive.
These plants then proceed to consume all the oxygen in the water, essentially killing off larger, more complex species, which need a lot of oxygen to survive.
“Strategies designed to reduce nutrient inputs on the land will improve the quality of water in near-surface parts of aquifers; however, decades may pass before quality improves in deeper parts of the aquifer, which serve as major sources for public-supply wells,” scientist Neil Dubrovsky explains.
“Unfortunately, similar time delays for improvements are expected for streams that receive substantial inputs of groundwater,” adds the USGS hydrologist, who was the lead scientist on the new study.