Post by Bozur on Apr 17, 2017 9:12:42 GMT -5
HOW DOES NEW YORK CITY TREAT ITS WATER SUPPLIES?
CATSKILL/DELAWARE SUPPLY
Due to the very high quality of our Catskill/Delaware supply, New York City is one of only five large cities in the country with a surface drinking water supply that does not require filltration as a form of treatment. Rather, the Catskill/Delaware supply operates under a Filtration Avoidance Determination (FAD), and the water from the supply is treated using two forms of disinfection to reduce microbial risk.
1) First, water is disinfected with chlorine before arriving at the Catskill/Delaware Ultra- violet (UV) Disinfection Facility. Chlorine is a common disinfectant added to kill germs and stop bacteria from growing on pipes.
2) The UV Disinfection Facility, located in the towns of Mount Pleasant and Greenburgh in West- chester County, is the largest of its kind in the world. It consists of 56 UV disinfection units that contain a total of 11,760 large UV light bulbs. The facility is designed to disinfect more than 2 billion gallons of water per day. At the facility, water is again disinfected as it ows under UV light. Exposure to UV light inactivates potentially harmful microorganisms, such as Cryptosporidium and Giardia. UV treatment does not change the water chemi- cally, as nothing is added except energy.
3) DEP also adds food grade phosphoric acid, sodium hydroxide, and fuoride to the water before sending it into distribution. Phosphoric acid creates a protective lm on pipes that reduces the release of metals, such as lead, from service lines and household plumbing. Sodium hydroxide is added to raise the pH and reduce corrosivity, which also reduces the potential for lead to enter water from house- hold plumbing. DEP is one of the many water suppliers in the United States that treat drinking water with a controlled, low level of fluoride for the protection of its consumers’ dental health. New York City’s drinking water has been treated with low levels of fuoride since 1966. According to the United States Department of Health and Human Services, fluoride is effective in preventing cavities when present in drinking water at an optimal level of 0.7 mg/L. To improve dental protection, DEP continuously monitors fluoride levels. During 2016, DEP provided continuous fluoride treatment on the Catskill/Delaware supply, except for two brief outages. In total, only 4.8 percent of the water produced by Catskill/Delaware supply was not fluoridated.
www.nyc.gov/html/dep/html/drinking_water/wsstate.shtml
CATSKILL/DELAWARE SUPPLY
Due to the very high quality of our Catskill/Delaware supply, New York City is one of only five large cities in the country with a surface drinking water supply that does not require filltration as a form of treatment. Rather, the Catskill/Delaware supply operates under a Filtration Avoidance Determination (FAD), and the water from the supply is treated using two forms of disinfection to reduce microbial risk.
1) First, water is disinfected with chlorine before arriving at the Catskill/Delaware Ultra- violet (UV) Disinfection Facility. Chlorine is a common disinfectant added to kill germs and stop bacteria from growing on pipes.
2) The UV Disinfection Facility, located in the towns of Mount Pleasant and Greenburgh in West- chester County, is the largest of its kind in the world. It consists of 56 UV disinfection units that contain a total of 11,760 large UV light bulbs. The facility is designed to disinfect more than 2 billion gallons of water per day. At the facility, water is again disinfected as it ows under UV light. Exposure to UV light inactivates potentially harmful microorganisms, such as Cryptosporidium and Giardia. UV treatment does not change the water chemi- cally, as nothing is added except energy.
3) DEP also adds food grade phosphoric acid, sodium hydroxide, and fuoride to the water before sending it into distribution. Phosphoric acid creates a protective lm on pipes that reduces the release of metals, such as lead, from service lines and household plumbing. Sodium hydroxide is added to raise the pH and reduce corrosivity, which also reduces the potential for lead to enter water from house- hold plumbing. DEP is one of the many water suppliers in the United States that treat drinking water with a controlled, low level of fluoride for the protection of its consumers’ dental health. New York City’s drinking water has been treated with low levels of fuoride since 1966. According to the United States Department of Health and Human Services, fluoride is effective in preventing cavities when present in drinking water at an optimal level of 0.7 mg/L. To improve dental protection, DEP continuously monitors fluoride levels. During 2016, DEP provided continuous fluoride treatment on the Catskill/Delaware supply, except for two brief outages. In total, only 4.8 percent of the water produced by Catskill/Delaware supply was not fluoridated.
www.nyc.gov/html/dep/html/drinking_water/wsstate.shtml
The regulatory process is long. Periodically, the Environmental Protection Agency adds chemicals to a watchlist of unregulated contaminants that are potentially harmful. Researchers work their way down the list to determine whether the chemicals pose a risk and at what levels, and the feasibility of regulating them. Often, data on occurrences and health effects just isn’t available.
The state’s Department of Health, which applies federal standards and sets its own, has been criticized for failing to devote sufficient resources to the issue. Most recently, it came under scrutiny for what residents in upstate Hoosick Falls said was a delayed response in alerting them about elevated levels of perfluorooctanoic acid, an unregulated chemical used to make Teflon products, in their water.
www.nytimes.com/interactive/2016/03/24/nyregion/how-nyc-gets-its-water-new-york-101.html?_r=0
The state’s Department of Health, which applies federal standards and sets its own, has been criticized for failing to devote sufficient resources to the issue. Most recently, it came under scrutiny for what residents in upstate Hoosick Falls said was a delayed response in alerting them about elevated levels of perfluorooctanoic acid, an unregulated chemical used to make Teflon products, in their water.
www.nytimes.com/interactive/2016/03/24/nyregion/how-nyc-gets-its-water-new-york-101.html?_r=0