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Jamaica well water study tests treatment methods

By Courtney Dentch

A study testing water quality at four Jamaica wells is under way, and the city is making progress toward deciding which treatment methods will work best for the area in hopes of building a full-scale treatment facility.

The six-month pilot program is taking samples from wells at 108th Avenue and 166th Street and using a variety of methods to clean the water, said Nicole Brown, a project coordinator for Malcolm Pirnie Inc. The engineering firm is working with the city’s Department of Environmental Preservation, which is running the project.

Although the water is only being used for testing now, the city hopes to be able to introduce it into the drinking supply in the future, Brown said.

The water at the wells known collectively as Station 6 has high concentrations of iron and manganese, two mineral components unhealthy for humans when consumed in large amounts, Brown said. She noted that the water at Station 6 does not contain chemical contaminants.

The pilot program, which began testing at the end of February, is a miniature version of a full-scale treatment facility and it cleans abut 100 gallons a minute, Brown said. Once the study is complete and the DEP chooses the best treatment methods, a larger plant will be built to clean more water, she said.

Construction of the full-size plant could begin in 2004, and the water could be added to the drinking supply by about 2006, she said.

To purify the water, the pH level, or acidity, must first be adjusted. The DEP is testing two methods for this. The first involves an aeration tower that forces oxygen into the water and expels the carbon dioxide, raising the pH to a safe level, Brown said. The second method uses sodium hydroxide, a chemical treatment that works in a similar way.

Next the iron and manganese must be removed, Brown explained. To simplify this step, the compounds are physically enlarged, so they are visible, turning the water a dark brown. Again, two processes are being tested — a chemical treatment called potassium permanganate and an ozone treatment. Each adds more oxygen to the water and enlarges the mineral particles.

Finally, the water is pushed through three types of membrane filters. Each filter contains thousands of straws about the size of a human hair, Brown said. The water runs through the straws, but the enlarged iron and manganese particles become trapped, she said. The water comes out clean and drinkable.

She added that technicians at the facility sample the water about 15 times a day and some testing is done on site, but samples are also sent to a state-certified lab for official results.

Reach reporter Courtney Dentch by e-mail at TimesLedger@aol.com, or by phone at 229-0300, Ext. 138.