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Groundwater System for 2004

Click here for larger Groundwater Distribution Area Map (980 Kb PDF)

Click here for larger Groundwater Distribution Area Map (PDF)

Historically, the Jamaica Water Supply Company (JWS), a privately owned water supply company, operated a group of wells that served the communities of southeast Queens and a part of Nassau County. In 1996, New York City purchased the portion of the JWS contained within the borough of Queens and took responsibility for the delivery of drinking water to the community. After acquiring the JWS wells the Department of Environmental Protection renamed the group of wells the Groundwater System. Comprised of 69 wells, the Groundwater System provides drinking water for up to 350,000 people. Residents within the system receive groundwater or a mix of ground and surface waters depending on the water demand and the available supply. In 2004, the Groundwater System (PWSID NY7011735) supplied an average of 6.4 million gallons per day (mgd) of drinking water from 7 wells, less than 1% of the City’s total usage.

Located in southeastern Queens, the Groundwater System covers an area of approximately 29 square miles. The neighborhoods serviced by the system include: Cambria Heights, Hollis, Holliswood, Jamaica, Jamaica Estates, Kew Gardens, Laurelton, Queens Village, Richmond Hill, Rosedale, St. Albans, South Jamaica, South Ozone Park and Springfield Gardens.

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Wells in Operation in 2004

The table below lists the wells that were in operation in 2004.

Well*Town Aquifer Depth (ft.) Present Well Capacity (mgd)
5 Hollis Magothy or Cretaceous Formation 275 1.73
5A Hollis Magothy or Cretaceous Formation 285 2.45
23A Cambria Heights Magothy or Cretaceous Formation 362 2.30
32 South Ozone Park Glacial or Post Jameco Formation 105 1.30
43A Richmond Hill Magothy or Cretaceous Formation 242 0.58
50 Fresh Meadows Magothy or Cretaceous Formation 254 1.44
55 Hollis Magothy or Cretaceous Formation 280 1.87

* - Wells are each assigned a number for easy reference. These numbers may be followed by the letters A, B, C, or D. These letters indicated multiple wells housed at the same location. For example W6, W6A, W6B, W6C, and W6D are all distinct wells at the same address.

For a more extensive listing encompassing all the wells within the Groundwater System, with location, aquifer, depth and operational information, see:

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Geology

An aquifer is a natural underground layer of porous, water-bearing materials (sand, gravel) usually capable of yielding a large amount or supply of water. Three aquifers run the length of geographic Long Island, which includes Brooklyn and Queens counties. The three are the Upper Glacial, which is the most shallow; the Magothy, which is the middle layer; and the Lloyd, which is the deepest. Formed approximately 60 million years ago, the three aquifers are separated by layers of clay.

Cross-Section of Brooklyn and Queens Aquifer (PDF)

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Treatment Information

All groundwater entering New York City’s distribution system is treated with chlorine, fluoride, food grade phosphoric acid, and, in some cases, sodium hydroxide. New York City uses chlorine to meet the New York State Sanitary Code and federal Safe Drinking Water Act disinfection requirements. Fluoride, at a concentration of one part per million, is added to help prevent tooth decay and has been added since 1966 in accordance with the New York City Health Code. Phosphoric acid is added to create a protective film on pipes that reduces the release of metals such as lead and copper from household plumbing. A sequestering phosphate is applied at several wells to prevent the precipitation of naturally occurring minerals, mostly iron and manganese, in the distribution mains and customers’ household piping. Air stripper facilities operate at several wells to remove volatile organic compounds (VOCs).

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Operational Information - 2004

In the Groundwater system Wells 5, 5A, 23A, 32, 43A, 50A and 55 were online in 2004. Wells 5, 5A, 23A and 50A were all operated remotely via telemetering from Station 6, which is the headquarters for groundwater operations, located in Jamaica, Queens. These four wells were started and stopped on a daily basis depending upon distribution demands. In general, the wells were started everyday between 5AM and 6 AM (as people start to wake up) and shut down when the system demand was met. They were then restarted around 3 PM as system demand increased (kids coming home from school) and shutdown again later in the evening (after 10PM when dishwashing and bathing are over). The remaining three wells in operation in 2004 (32, 43A and 55) were operated on site. These wells normally run 24 hours a day.

Individual Well Information:

Well 5: Originally put into service in 1924, Well 5 was designed for a flow rate of 1200 gallons per minute (gpm). The water is pumped from the wellhead, or water source, through an air stripping plant in order to remove any volatile organic compounds (VOCs) from the water before it is discharged into the distribution system.

Well 5A: Originally put into service in 1954, Well 5A was designed for a flow rate of 1600 gpm. As with Well 5, the water is pumped from the wellhead through an air stripping plant to remove the VOCs before reaching the distribution system. Well 5A is currently inactive due to a need to overhaul the pump. The motor for this well failed on October 30, 2004 and, pending repair, was out of service for the remainder of 2004.

Well 23A: Originally put into service in 1933, Well 23A was designed for a flow rate of 1200 gpm. The water is pumped from the wellhead into a one million gallon storage tank before it is discharged into the distribution system.

Well 32: Originally put into service in 1952, Well 32 was designed for a flow rate of 1194 gpm. The water is pumped from the wellhead directly into the distribution system. Well 32 was taken out of service on August 23, 2004 due to a malfunction of the well pump, and returned to service on November 5, 2004 after the pump was replaced.

Well 43A: Originally put into service in 1960, Well 43A was designed for a flow rate of 1200 gpm. As with Well 32, the water is pumped from the wellhead directly into the distribution system. Due to a faulty pump, May 29, 2007 and, pending repair, remained out of service for the duration of 2004.

Well 50A: Originally put into service in 1962, Well 50A was designed for a flow rate of 1000 gpm. The water is pumped from the wellhead through an air stripping plant to remove the VOCs before being discharged into the distribution system.

Well 55: Originally put into service in 1973, Well 55 was designed for a flow rate of 1200 gpm. In the late 1990’s, VOCs were detected and Well 55 was taken out of service. With the drought of 2002, DEP decided to enhance alternative water sources for use during drought conditions. Because of the moderate contamination levels at Well 55, it was decided that the well could be used as an alternative water source if wellhead treatment was provided to ensure acceptable water quality. A Granular Activated Carbon (GAC) Filter system was installed on the discharge of the well; this removes VOCs and Methyl Tertiary-Butyl Ether (MTBE), the gasoline additive. In order to confirm that the new system was complete and would operate against the distribution back-pressure, the well and GAC system were run to the distribution system for 2 weeks, beginning December 24, 2003 through January 9, 2004. The trial was also used to obtain a Completed Works Approval (required after any potable water supply system modification) from the New York City Department of Health and Mental Hygiene, which was given in August 2004. DEP plans to use Well 55 in the future only during drought emergencies.

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Water Quality Data

Index Numbers:

DEP assigns index numbers to sampling locations throughout the distribution system.  The nomenclature of the index for a well sample location signifies the status of the water at a specific tap.  An index number followed by the letters E, F or T denotes sampling sites that are treated, or finished groundwater.  Well index numbers that have no letter after the number, or are followed only by the letters A, B, C, D, I or S are considered untreated, or raw water.  Examples of untreated water IDs are W5 and W23A.  Examples of treated water are W5E and W23AT. The following table illustrates this in greater detail:

Index Numbers Description
W##, W##A-D, I, S Groundwater wells sampling points prior to final treatment
W##E Effluent finished groundwater from wells with air-stripping
W##F Finished groundwater effluent from wells without any special treatment
W##T Treated finished groundwater effluent from sequestering/iron treatment wells
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Definitions

GAC – granular activated carbon, a form of particulate carbon manufactured with increased surface area per unit mass to enhance the adsorption of soluble contaminants.

gpm – Gallons per minute

mgd – Million gallons per day

MTBE - Methyl Tertiary-Butyl Ether, a gasoline additive used to as an octane booster.

VOCs – volatile organic compounds, a class of organic compounds that includes volatile liquids.

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Reservoir Levels

Current: 89.9%

Normal: 80.4%