Post by L Roebuck on Jul 24, 2006 8:59:31 GMT -5
The dirt on groundwater
LI's drinking supply, though considered good by experts, is vulnerable since it's pumped from aquifers
BY JENNIFER SMITH
Newsday Staff Writer
As Long Islanders spill gas at the pump, kill weeds in their backyards and even take showers at home, they contribute to an ever-growing suite of contaminants polluting a fragile and ancient source of drinking water deep beneath the ground.
The recent drinking water contamination in West Hempstead, along with an E. coli bacterial scare on Fire Island and a brewing political battle over drilling into the deepest and purest of Long Island's aquifers, all served as fresh reminders of the water supply's vulnerability.
Although the quality of the drinking water is considered good and is constantly tested, scientists are eyeing an emerging group of potential contaminants: medications and personal-care products whose effect on human health -- after they are flushed down drains into septic systems and then into groundwater -- is unknown. And some environmental advocates say the groundwater is poorly protected by a patchwork of federal and state regulations they say address some hazards -- such as leaking petroleum storage tanks -- but fail to look at the big picture.
What Long Island needs, says state Sen. Carl Marcellino (R-Syosset), chair of the Senate Environmental Conservation Committee, is nothing less than a "water czar" to coordinate the various agencies that regulate the region's water.
"Things like MTBE, those are tough problems," said Henry Bokuniewicz, a professor at Stony Brook University's marine sciences research center and director of the university's groundwater institute. "Pollution and contamination are not problems that are going to go away. But I think as we become more and more sophisticated in handling how the contamination happens and the pathways in which it's getting to the groundwater, we're going to be better at living with it."
The water here is vulnerable because the water flowing out of our taps doesn't come from protected reservoirs in the Catskills. It's pumped up from an underground aquifer system whose layers trap and filter precipitation as it slowly trickles down thousands of feet through the ground.
As water testing technology improves, traces of previously undetectable substances have been found -- pharmaceutical by-products that people ingest and then excrete that can work their way into the water supply in unsewered areas.
"Caffeine, nicotine, Prozac -- all these things are starting to show up, and you can't control those like you control a tank at a gas station," Bokuniewicz said. "We need to find out where they come from, and find out if they're a health threat. The unknowns are legion."
The new contaminants of concern join a list of usual suspects -- pesticides, chemicals and nitrates from fertilizer and human waste.
MTBE, a now-banned gasoline additive that moves swiftly through groundwater, continues to show up in private and public supply wells and is expected to persist as contaminated plumes from unreported gasoline leaks and spills make their way deeper into the groundwater.
Some fronts may be improving. State and local health and environmental officials say the threat from pollutants such as industrial solvents is waning. And they say progress in regulation and cleanup of pollutants over the past decades have decreased levels of many contaminants in public supply wells.
"Overall groundwater quality is improving, not getting worse," said Tom Maher, Nassau's director of environmental coordination.
But some environmental advocates disagree. They say Long Island's groundwater is in serious trouble that can't be solved by simply drilling deeper for clean water and that more attention must be paid to safeguard the source of the water -- not just that which flows from the tap.
"Groundwater is the last national resource that there is no comprehensive federal law to protect," said Erik Olson, a groundwater expert and director of advocacy for the Natural Resources Defense Council. "It's a very precious resource, and once it's contaminated it's almost impossible and extremely expensive to try and clean up."
The fragility of Long Island's groundwater is a function of the structure of the aquifer system, which is less like an underground bathtub than it is a porous geological parfait. As rain moves from the surface through the ground, it travels down and laterally through layers of gravel, sand and clay that rest on top of sloping bedrock.
The layers form a lopsided wedge, thin in northwestern Nassau and Queens, but extending some 2,000 feet deep along eastern Suffolk's South Shore. As it moves lower, groundwater also moves slowly toward the ocean, eventually discharging into Long Island Sound or the Atlantic Ocean. Estimates of how much water is stored in the various layers range from 10 trillion to 70 trillion gallons.
Historically most drinking water was pumped from the shallow layer known as the Upper Glacial aquifer. But as contaminants increasingly fouled wells there, water suppliers began moving deeper, tapping into the Magothy aquifer -- the biggest and most important source of Long Island's water -- and even into the Lloyd aquifer. Capped by thick clay that slows groundwater's progress to a crawl, the Lloyd aquifer takes the longest to recharge and, in its deepest points along the South Shore, contains water that is thousands of years old.
The health of groundwater depends largely on what happens on the surface above it, especially in areas such as the pine barrens, whose porous, sandy soils are the main recharge areas for the Magothy and Lloyd aquifers.
While geologists regard the different aquifers as part of a unified water system, generalizations about pollution levels in Long Island's groundwater are difficult to make. The mix of contaminants has changed over time, and what you find depends on where and at what depth water is sampled.
Perhaps the most comprehensive recent review of the quality of the water below us is to be found in a 2003 report on Long Island groundwater commissioned by the state Health Department in conjunction with Nassau and Suffolk.
The report found that nitrates, which seep into groundwater from cesspools, agricultural fertilizer and lawn care products, have historically been a water quality issue across the Island. In recent years, sewering in Nassau County has diminished the discharge of nitrates to the Upper Glacial aquifer.
But nitrate contamination remains a concern in Suffolk County. There, many heavily developed areas rely on cesspools and local sewage treatment plants to process human waste. Pesticides also have been found in shallower Suffolk groundwater in agricultural and heavily landscaped areas such as golf courses, and to a lesser degree in Nassau.
Sewering has put a dent in the amount of volatile organic compounds such as industrial solvents discharged to Nassau's shallower groundwater, and overall concentrations in Suffolk remain relatively low, the water assessment report found. But volatile organic compounds -- many of which are known carcinogens -- continue to be found in deeper groundwater, as plumes and spills from past years descend. During the past 25 years, volatile-organic-compound contamination has resulted in the abandonment of 24 public supply wells in Nassau County, according to the report, which noted that it "continues to be a potential threat to drinking water supplies in Nassau and Suffolk Counties."
MTBE remains an Islandwide problem, although experts, officials and environmental advocates disagree on its severity. MTBE was found in the raw water at 7 percent of Nassau public supply wells in 2000 and in about 6 percent of those in Suffolk in 2001. Last month's health alert in West Hempstead, when 32,000 residents were told not to drink their tap water because it was contaminated with MTBE, marked the first time on Long Island that levels in public drinking water exceeded the state drinking water standard of 10 parts per billion.
Article: www.newsday.com/news/local/longisland/ny-liwate0714,0,5253413.story?coll=ny-top-headlines
LI's drinking supply, though considered good by experts, is vulnerable since it's pumped from aquifers
BY JENNIFER SMITH
Newsday Staff Writer
As Long Islanders spill gas at the pump, kill weeds in their backyards and even take showers at home, they contribute to an ever-growing suite of contaminants polluting a fragile and ancient source of drinking water deep beneath the ground.
The recent drinking water contamination in West Hempstead, along with an E. coli bacterial scare on Fire Island and a brewing political battle over drilling into the deepest and purest of Long Island's aquifers, all served as fresh reminders of the water supply's vulnerability.
Although the quality of the drinking water is considered good and is constantly tested, scientists are eyeing an emerging group of potential contaminants: medications and personal-care products whose effect on human health -- after they are flushed down drains into septic systems and then into groundwater -- is unknown. And some environmental advocates say the groundwater is poorly protected by a patchwork of federal and state regulations they say address some hazards -- such as leaking petroleum storage tanks -- but fail to look at the big picture.
What Long Island needs, says state Sen. Carl Marcellino (R-Syosset), chair of the Senate Environmental Conservation Committee, is nothing less than a "water czar" to coordinate the various agencies that regulate the region's water.
"Things like MTBE, those are tough problems," said Henry Bokuniewicz, a professor at Stony Brook University's marine sciences research center and director of the university's groundwater institute. "Pollution and contamination are not problems that are going to go away. But I think as we become more and more sophisticated in handling how the contamination happens and the pathways in which it's getting to the groundwater, we're going to be better at living with it."
The water here is vulnerable because the water flowing out of our taps doesn't come from protected reservoirs in the Catskills. It's pumped up from an underground aquifer system whose layers trap and filter precipitation as it slowly trickles down thousands of feet through the ground.
As water testing technology improves, traces of previously undetectable substances have been found -- pharmaceutical by-products that people ingest and then excrete that can work their way into the water supply in unsewered areas.
"Caffeine, nicotine, Prozac -- all these things are starting to show up, and you can't control those like you control a tank at a gas station," Bokuniewicz said. "We need to find out where they come from, and find out if they're a health threat. The unknowns are legion."
The new contaminants of concern join a list of usual suspects -- pesticides, chemicals and nitrates from fertilizer and human waste.
MTBE, a now-banned gasoline additive that moves swiftly through groundwater, continues to show up in private and public supply wells and is expected to persist as contaminated plumes from unreported gasoline leaks and spills make their way deeper into the groundwater.
Some fronts may be improving. State and local health and environmental officials say the threat from pollutants such as industrial solvents is waning. And they say progress in regulation and cleanup of pollutants over the past decades have decreased levels of many contaminants in public supply wells.
"Overall groundwater quality is improving, not getting worse," said Tom Maher, Nassau's director of environmental coordination.
But some environmental advocates disagree. They say Long Island's groundwater is in serious trouble that can't be solved by simply drilling deeper for clean water and that more attention must be paid to safeguard the source of the water -- not just that which flows from the tap.
"Groundwater is the last national resource that there is no comprehensive federal law to protect," said Erik Olson, a groundwater expert and director of advocacy for the Natural Resources Defense Council. "It's a very precious resource, and once it's contaminated it's almost impossible and extremely expensive to try and clean up."
The fragility of Long Island's groundwater is a function of the structure of the aquifer system, which is less like an underground bathtub than it is a porous geological parfait. As rain moves from the surface through the ground, it travels down and laterally through layers of gravel, sand and clay that rest on top of sloping bedrock.
The layers form a lopsided wedge, thin in northwestern Nassau and Queens, but extending some 2,000 feet deep along eastern Suffolk's South Shore. As it moves lower, groundwater also moves slowly toward the ocean, eventually discharging into Long Island Sound or the Atlantic Ocean. Estimates of how much water is stored in the various layers range from 10 trillion to 70 trillion gallons.
Historically most drinking water was pumped from the shallow layer known as the Upper Glacial aquifer. But as contaminants increasingly fouled wells there, water suppliers began moving deeper, tapping into the Magothy aquifer -- the biggest and most important source of Long Island's water -- and even into the Lloyd aquifer. Capped by thick clay that slows groundwater's progress to a crawl, the Lloyd aquifer takes the longest to recharge and, in its deepest points along the South Shore, contains water that is thousands of years old.
The health of groundwater depends largely on what happens on the surface above it, especially in areas such as the pine barrens, whose porous, sandy soils are the main recharge areas for the Magothy and Lloyd aquifers.
While geologists regard the different aquifers as part of a unified water system, generalizations about pollution levels in Long Island's groundwater are difficult to make. The mix of contaminants has changed over time, and what you find depends on where and at what depth water is sampled.
Perhaps the most comprehensive recent review of the quality of the water below us is to be found in a 2003 report on Long Island groundwater commissioned by the state Health Department in conjunction with Nassau and Suffolk.
The report found that nitrates, which seep into groundwater from cesspools, agricultural fertilizer and lawn care products, have historically been a water quality issue across the Island. In recent years, sewering in Nassau County has diminished the discharge of nitrates to the Upper Glacial aquifer.
But nitrate contamination remains a concern in Suffolk County. There, many heavily developed areas rely on cesspools and local sewage treatment plants to process human waste. Pesticides also have been found in shallower Suffolk groundwater in agricultural and heavily landscaped areas such as golf courses, and to a lesser degree in Nassau.
Sewering has put a dent in the amount of volatile organic compounds such as industrial solvents discharged to Nassau's shallower groundwater, and overall concentrations in Suffolk remain relatively low, the water assessment report found. But volatile organic compounds -- many of which are known carcinogens -- continue to be found in deeper groundwater, as plumes and spills from past years descend. During the past 25 years, volatile-organic-compound contamination has resulted in the abandonment of 24 public supply wells in Nassau County, according to the report, which noted that it "continues to be a potential threat to drinking water supplies in Nassau and Suffolk Counties."
MTBE remains an Islandwide problem, although experts, officials and environmental advocates disagree on its severity. MTBE was found in the raw water at 7 percent of Nassau public supply wells in 2000 and in about 6 percent of those in Suffolk in 2001. Last month's health alert in West Hempstead, when 32,000 residents were told not to drink their tap water because it was contaminated with MTBE, marked the first time on Long Island that levels in public drinking water exceeded the state drinking water standard of 10 parts per billion.
Article: www.newsday.com/news/local/longisland/ny-liwate0714,0,5253413.story?coll=ny-top-headlines