The Future of NYC Drinking Water

Subject: The Future of NYC Drinking Water
Date: 10/1/2004 3:25:49 PM GMT Daylight Time
From: MarianR451

A REMINDER

The Croton Watershed Clean Water Coalition cordially invites you to attend a lecture byProfessor Audrey Levine, Ph.D., who will speak on Membrane Filtration and its Applications to the NYC Drinking Water Supply

Date: Monday, October 18, 2004
Time: 5 PM
Place: The Roger Smith Hotel/ Winthrop Room
501 Lexington Avenue at 47th Street
RSVP: Please call Wendy: at 914 234-6470
or Marian: at 914 234- 3179
Please respond no later than Friday, October 15 to let us know that you will
be attending the lecture.Thank you

As you know, the NYC Department of Environmental Protection (DEP) is planning to build $1.5 billion chemical treatment/filtration plant for Croton water in order to comply with federal and state regulations regarding drinking water supplies.

DEP's process is based on Dissolved Air Flotation with Filtration (DAF/F), a technology that involves a mix of chemicals to produce coagulation, sedimentation, and flocculation.

In addition to the need for a disinfectant, as mandated by federal law, DEP would also use UV as an extra precaution to inactivate any remaining cryptosporidium, a dangerous pathogen particularly to the immune-deficient, the elderly, and the very young.

Besides its exorbitant cost, the plant would require an extensive footprint and also have dire environmental impacts on a neighboring community. DEP decided to use DAF/F back in 1999.

However, in the intervening years, membrane filtration, in particular
“ultrafiltration” is rapidly becoming the technology of choice of drinking water purveyors, replacing DAF/F.

In 2001, there were 20 DAF/F plants operating in the US. Only five of them were built between 1999-2001. In 2001, there were 80 membrane plants operating in the US, counting only microfiltration and ultrafiltation facilities. Sixty of those plants were built between 1999-2001.

Plans for a 250 million gallon per day (mgd) plant are being considered in Portland, Oregon - close to the 290 mgd for the Croton.

In 2004, there are, at least, 120 ultrafiltration and microfiltration facilities, while the number of DAF/F plants appears to have remained constant.

There are solid reasons for the rapidly increasingly popularity of membrane filtration. A membrane filtration facility would require about only 1/6th the space of a DAF/F plant. Specifically, for the Croton, this would allow wide flexibility in the choice of a site without the need to use parkland as is now the case.

Membrane filtration would require significantly fewer chemicals in the pretreatment process. The cost has decreased dramatically, with present costs per gallon of filtered of water being well below the cost of DAF/F.Most important, the final product of a membrane filtration plant is superior in terms of safety to DAF/F plant.

The small pores of a membrane act as an absolute barrier against cryptosporidium, giardia and other pathogens. That is not the case with DAF/F.Unfortunately, DEP appears committed to DAF/F. Before the point of no return point is reached, we would like to create an opportunity for discussions with them.

An informed public is our best guarantee that they will listen. We have been talking with some of the country's top experts in the field of membrane filtration, and have asked Professor Audrey Levine, Ph.D., Associate Professor of Civil & Environmental Engineering at the University of South Florida, in Tampa, to come and talk to us on the subject.

Her areas of expertise include drinking water treatment systems; wastewater reclamation and reuse; disinfection chemistry and microbiology; membrane processes; groundwater recharge, scale and corrosion control; reactivity of particulate and macromolecular associated contaminants, and water quality modeling. She has published a long list of research papers.

Professor Levine was selected to audit several water utilities in Florida. We very much hope that you will attend the lecture and let us have the benefit of your thoughts and expertise at this critical juncture.

The future of New York City depends, to a large extent, on being able to supply its residents and the greater metropolitan area with safe, clean and affordable drinking water. We should not miss the opportunity to examine all options to accomplish this.

Marian H. Rose, PresidentCWCWCPlease visit our website:
www.newyorkwater.org