美国国家公共电台 NPR Trump's Budget Would Eliminate A Key Funder Of Research On Coastal Pollution（在线收听）

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For millions of Americans, what they flush down the toilet goes into a septic tank. Septic tanks are convenient, but sometimes they pollute our waterways. Scientists are trying to track down that pollution with help from a federal program called Sea Grant. It's part of the National Oceanic and Atmospheric Administration, and it's a program President Donald Trump's budget would eliminate next year. NPR's Christopher Joyce reports on what would be lost if that happens.

CHRISTOPHER JOYCE, BYLINE: I'm going to start in a yard next to the Severn River in Maryland. It's my yard, actually. Underneath my feet is a septic tank, my own personal sewer, you could say. Hopefully it's not leaking. If it were, I wouldn't see it anyway. It's underground, and it would leak invisibly downhill. So let's walk downhill. We can listen to a little walking music along the way.

(SOUNDBITE OF ORNETTE COLEMAN'S "TURNAROUND")

JOYCE: OK, I'm in a little park now with trees and grass, a tiny stream here. The river is off to my left. And up above me are a couple hundred homes with septic tanks. And even if those tanks aren't broken, they will leak a little and pollute the water way here. And once pollution is in the river, it's really hard to tell where it came from. Although, there are some people who think they can track down the source of pollution. I like to call them septic detectives.

LORA HARRIS: (Laughter) Septic detective.

JOYCE: Lora Harris actually calls herself a coastal ecologist. But today she is in fact chasing septic waste along a wooded gully behind a housing development. She's looking for a particular kind of pollution - nitrogen.

HARRIS: A lot of it comes out of toilets, and a lot of it comes out of farms. And a lot of it comes falling out of the sky from us combusting fossil fuels. And so this particular project is focused on what's coming out of the toilets.

JOYCE: We find a small stream just a few inches deep.

HARRIS: Do you want me to start on those bottles?

ANDREW HEYES: Sure can.

JOYCE: Harris and colleague Andrew Heyes start filling bottles with stream water.

HEYES: (Laughter).

JOYCE: Harris explains that nitrogen in a river or bay is fine in the right amount, but too much of it creates dead zones. In fact, excess nitrogen is the single largest pollution problem in coastal waters from the Chesapeake Bay to the Gulf of Mexico. And everyone blames someone else for it.

So Harris's team at the University of Maryland's Center for Environmental Science is developing a chemical fingerprint for one source - septic tanks. It would help local officials pinpoint the sources of pollution and stop it.

HARRIS: They're keenly interested to know if the water quality problems are because of the septic systems, the farms or if they're because of problems happening all the way up in Pennsylvania.

JOYCE: OK, back on the road traveling to yet another site. It's pretty country.

Harris hopscotches (ph) all over the Chesapeake Bay area to sample water mostly near housing developments. Our second stream runs along a highway. As Harris wades through, Heyes explains that the septic fingerprint they're working on is more than just nitrogen compounds. It's a cocktail of chemicals from your home and your body.

HEYES: Things like caffeine, some of the compounds you use in your soap, pharmaceuticals. All those things that you flushed down the toilet or pass through your body end up going through the septic system.

JOYCE: OK, mission accomplished. Now back to the laboratory to find out what's in the water.

The lab sits on a peninsula overlooking the Chesapeake Bay. Chemist Michael Gonsior oversees this part of the work. Gonsior studies what's in water right down to the molecular level.

MICHAEL GONSIOR: The complexity in the water, even in natural systems, is absolutely mind-boggling. It's extremely diverse. And I love complex mixtures. It's my thing.

JOYCE: Gonsior has identified about 15,000 compounds in septic water. He shows me a paper plot that displays some of them as peaks and valleys. It looks completely different from a plot of bay water or even of treated sewage, and it's good enough to pick septic waste out of a lineup.

GONSIOR: Because you really want to say, OK, this team here is surely impacted by septics.

JOYCE: The team still has to prove the technique is ironclad. Whether they'll get a chance depends on continued funding through Sea Grant, which supports more than 800 projects like this one around the country. The Trump administration plans to eliminate all of them. Congress so far is keeping them running at least for the rest of this fiscal year. Christopher Joyce, NPR News.

(SOUNDBITE OF A.S.M. AND WAX TAILOR SONG, "SAY YES")