- The Washington Times - Wednesday, March 22, 2006

Fairfax Water does not have to do any marketing to sell its product.

The Fairfax-based water supplier has 1.3 million to 1.4 million customers in Northern Virginia, including major portions of Fairfax County, where it has more than 800,000 customers. Fairfax Water also distributes water to wholesale customers in Loudoun and Prince William counties, Alexandria and the town of Herndon, which in turn distribute water to more than 500,000 customers.

Direct customers in Fairfax County pay $1.45 for each 1,000 gallons of water used when they turn on the tap, take a shower or water the lawn. (That price will increase to $1.50 on April 1.)

“Water is essential to life,” says Jeanne Bailey, spokeswoman for Fairfax Water, who adds that customers expect the electricity or the phones to be out of service occasionally, but not their water, even though most customers have no idea what happens to the water on its journey to the faucet.

In Fairfax County, the journey begins at the Potomac and Occoquan rivers. The Corbalis Treatment Plant in Herndon and three treatment plants on the Occoquan service most of the county and several wholesale customers. The four plants produce an average of 145 million gallons of water a day for more than 235,000 customers, who expect their water to be free of contaminants and to taste good.

“Every element that is out there is in water,” says Nickolas Zimmermann, associate professor of animal and avian sciences at the University of Maryland in College Park. “That doesn’t make water bad. What makes water bad is when you have high levels of [contaminants] in drinking water.”

The Environmental Protection Agency sets national water-quality standards for contaminants that potentially could occur in public water systems. The Safe Drinking Water Act, passed by Congress in 1974, gives EPA the authority to set the standards, which the states, in turn, enforce. The EPA regulates surface water, which comes from rivers and lakes, and provides recommendations for groundwater.

“The EPA doesn’t regulate private wells. There’s just too many of them,” says Mr. Zimmermann, who holds a joint doctorate in poultry and veterinary sciences.

The EPA requires the removal of approximately 90 contaminants — Fairfax Water has requirements for 122 contaminants — that may appear in drinking water, including metals, chemicals, carcinogens and living organisms. The EPA sets a legal limit, called a maximum contaminant level, that differs for each contaminant. Primary contaminants have the potential to cause public health problems, while secondary contaminants, which are covered by nonenforceable guidelines, can cause aesthetic and cosmetic effects, such as water or tooth discoloration.

“People think we have an awful lot of standards,” says Rick Rogers, chief of the drinking water branch for EPA’s mid-Atlantic region. “That’s a mere drop in the bucket compared to the number of contaminants that could enter the water supply.”

The EPA reviews the contaminants list every five years and adds anything considered harmful to health that can be treated with the technology available, Mr. Rogers says.

“Filters, membranes, pumps, all of that is there to remove contaminants from the water and to ensure clean water comes out and is delivered,” says Wes Kleene, director of the office of drinking water for the Virginia Department of Health in Richmond.

The treatment process at the Corbalis plant, for example, starts with two feeder pipes that bring surface water from the Potomac River to the plant, says Douglas Grimes, manager of water production for Fairfax Water.

“Depending on the condition of the river, that will dictate which treatments we’ll use,” Mr. Grimes says about the water’s acidity level and turbidity, or clearness.

Fairfax Water adds chemicals such as potassium permanganate, which breaks up algae, to treat specific water conditions before the regular treatment process begins.

Water is treated in a five-step process as it moves through the plant by force of gravity, Mr. Grimes says.

Coagulants are added to the water to cause small particles to adhere together. The water is mixed with turbine mixers in a basin, where fluoride and other chemicals are added, and mixed again at a slower speed in the second step of the process, called flocculation. Large particles are forced to bump into each other and form what is called floc.

“The idea is to get all of the water in contact with the chemical,” Ms. Bailey says.

As floc increases in size, the particles become heavy and sink into a sedimentation basin, where they are removed in solid form in the third step of the process.

“We’ve removed the big particles, but the water is still biologically active,” Mr. Grimes says.

Ozone, an oxidant, is added to oxidize or break apart the carbon in the water and allow for easier filtration of any remaining fine particles in the fourth step, Mr. Grimes says.

In the final step, disinfection, chlorine is added to kill harmful bacteria, viruses and microorganisms, along with caustic soda to prevent corrosion of pipes and zinc orthophosphate to help prevent lead leaching in older pipes.

The District of Columbia Water and Sewer Authority, for example, was out of compliance for lead levels in drinking water in 2004 following a change in water chemistry from its supplier. The authority is required to monitor the levels and submit samples to the EPA.

For more than a year, lead levels have been in decline, says Michele Quander-Collins, director of public affairs for the authority.

The Washington Aqueduct, which serves the District, Falls Church and Arlington County, treats water from the Potomac River, using a similar treatment process to that used by Fairfax Water.

“It’s a multibarrier approach to providing safe water,” says Lloyd Stowe, chief of operations for the Washington Aqueduct, which operates the Dalecarlia and McMillan treatment plants and is based in Northwest. “We treat an average of 180 million gallons a day between both of the plants. You wouldn’t run all that flow through one big unit. You have to divide it into smaller units.”

The city of Falls Church pumps the water it purchases from the Washington Aqueduct and Fairfax Water through a 485-mile pipeline distribution system to its customers, raising water pressure at a central pumping station to accommodate pressure drops from friction inside the pipes, says Robert Etris, director of public utilities for Falls Church.

“It’s much more complicated than the average person has any notion of,” Mr. Etris says. “The easy part is moving large parts of water from point A to point B.”

The hard part, he says, is providing water that is 100 percent safe to drink.

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