Q&A: How safe is Philly's water?

The water crisis in Flint, Mich., where residents unknowingly drank water with harmful levels of lead, has brought new scrutiny to public water-supply systems.

How does Philadelphia's water rate?

Officials will address that question at the Academy of Natural Sciences of Drexel University on Tuesday evening. Debra McCarty, the new commissioner of the Philadelphia Water Department, will be joined by Lynn Thorp, national campaigns director for Clean Water Action, and Jerry Fagliano, chair of the Department of Environmental and Occupational Health at Drexel University's Dornsife School of Public Health. (Information: www.ansp.org/visit/events.)

Before joining Drexel in 2015, Fagliano spent 30 years as an epidemiologist with the New Jersey Department of Health. He led an investigation into a childhood cancer cluster in Toms River, N.J., which was the subject of a Pulitzer Prize-winning book by Dan Fagin.

Fagliano recently talked to us about Philadelphia's water, including a new program to help property owners replace lead pipes leading to their homes.

What's the most important thing people in Philadelphia should know about their drinking water?
Speaking as a long-term customer as well as a scientist who has studied water quality, people should really appreciate that the Philadelphia Water Department provides a high-quality product at an affordable price. Generally, the water quality in Philadelphia is quite good.

But there are challenges. The most important one for Philadelphia, whose source water comes from the rivers - the Delaware and the Schuylkill - is that protecting those source waters is really essential to assuring the long-term quality of the drinking water. Generally, the quality of source waters has been improving over the years, through enforcement of the Clean Water Act. But they still remain susceptible to agricultural runoff; runoff from cities; industrial discharges; wastewater from populations that live upstream; and, potentially, from spills of hazardous materials.

Philadelphia is at the bottom of those watersheds. There is a lot of activity that takes place upstream. Continued vigilance is needed to ensure that there are no problems, or fewer threats to our water supply.

Are there any other big challenges?
Ensuring proper treatment of the water once it gets to the city's intakes also is an ongoing challenge. Ensuring that infectious agents such as bacteria and viruses are not present in the treated water is the primary job of water-treatment plants. They do that through filtration and the addition of disinfectants. But the process of disinfection also produces chemical by-products, so the challenge is to both ensure effective water treatment while minimizing disinfection by-products. The city does a good job of striking that balance.

Still, one thing we've done in our house to minimize the taste and odors that can result from disinfection is to run the water in the morning for a few minutes, then fill a water pitcher and put it in the refrigerator. It chills the water - cold water in general just tastes better - and it lets the volatile chemicals that can be produced by disinfection dissipate.

Do Philadelphians have to worry about lead in their water?
Typically, water that the system provides has very low or undetectable levels of lead when it reaches the service lines that go to people's houses. But some of those lines, which are the responsibility of the property owner, are made of lead. Lead also can be found in the solder that connects people's copper plumbing within their homes. It can even be found in some faucet fixtures. When the water comes into contact with those pipes or fixtures for a period of time, lead can leach into it.

There are a couple of approaches. Water systems can treat the water to minimize the amount of corrosion, which is how the lead gets into the water. Philadelphia is doing that. The city's monitoring program has shown that over the past 20 years or so, its anticorrosion treatment has been effective.

But it doesn't mean there's no corrosion, so that's where individual actions can help. People can simply flush their water in the morning or after any period of time the water has sat for a long time. If you run the water for a couple minutes, until it feels cold, that typically means you're now drawing water from the street main. That water should be relatively free of lead.

In Philadelphia, there also is a renewed effort to gradually replace as many of the lead service lines as possible. One program the city is implementing is replacing these service lines at no cost to homeowners in areas where the city is going to be doing street main work. Another program is to notify people if they are aware that there is a lead service line to take steps on their own to replace those lines. And they are working on developing zero-cost loans to do that.

What about schools? Elevated lead levels were found in the water at schools in Newark, N.J.
Lead exposure is mostly a concern in children, so schools and day-care centers need to be especially attentive. There are requirements for schools to eliminate fountains and coolers that have lead components, but there's still a need for flushing the water in the morning or after it's been sitting for a long time to make sure the water the children are drinking is fresh from the mains. The reason is that schools often are large buildings with relatively low water flow, so there's an opportunity for water to sit for a long period of time, and for lead to be present.

The U.S. Environmental Protection Agency has a very good guidance document for schools and day-care centers on how to implement a flushing program. I would advise people to look at that and make sure schools are following that guidance.

What about emerging pollutants, such as pharmaceuticals and personal-care products?
Again, it goes back to source-water protection. Some of the pharmaceuticals that people take goes through their bodies, ends up in the wastewater, goes through the wastewater treatment plant, and can be detected in trace quantities in drinking water downstream. Those pharmaceuticals may or may not have an impact on human health. But this points to the need to really be careful about what we put in our wastewater stream. Every individual has an obligation to protect water quality for their own watershed and for the people who live downstream from them.

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