By JAMES GLANZ
BAGHDAD, Iraq, July 11 — A few feet from a gray waterfall of stinking untreated sewage, Firas Shihab Ahmed, a chemical engineer at the Iraqi Ministry of the Environment, reached over the side of his boat on Sunday and plunged an amber glass bottle into the Tigris River.
He filled the bottle, holding it with a latex-gloved hand, and marked it as his 14th sample of the day, taken at a place known as the Wahda discharge point — the source of the sewage cascading into the river.
As humdrum and low-tech as that action is by American standards, Mr. Ahmed had just performed an act of great courage. Three months ago, for making exactly the same measurement in the Tigris, he and several other colleagues from the ministry were shot at, rounded up, hooded and handcuffed by the Iraqi police working with American troops who apparently decided that he had been acting suspiciously.
It is still so extraordinary to see boats traveling any distance on the Tigris, which has become a smelly, shrunken, deserted, refuse-strewn ghost of its former splendor, that dozens of curious employees of a nearby power plant applauded and cheered when Mr. Ahmed capped his amber bottle and placed it among the others in what resembled a picnic basket.
More extraordinary still was how Mr. Ahmed had returned to his work, which he and other Iraqi engineers on the trip say is essential for determining how to restore the Tigris to some semblance of what it once was.
He was assisted by an American environmental advocate and anti-war activist named Anna Bachmann, who has been back and forth between Iraq and her home, Port Townsend, Wash., a couple of times. Ms. Bachmann, who had solicited donations from residents in Port Townsend, used the money to rent three motorboats, with skippers and interpreters, for a trip along nearly the entire length of the city.
Then Ms. Bachmann negotiated with the Iraqi river police the right of safe passage — an agreement that repeatedly ran aground. The trip was ultimately truncated when a shadowy Iraqi security official named Major Basim telephoned to say that he was overwhelmed with calls from people who were astonished to see boats on the Tigris. He insisted that it was no longer safe to continue.
But by then, Mr. Ahmed and Baraa Sharaf al-Deen, another engineer at the ministry, had taken 14 critical samples — bacteria levels, heavy metals, phosphates and other pollutants — of a kind that had been impossible since the American-led invasion of Iraq last year.
"There is risk," Mr. Ahmed said, basking in the applause of the power plant workers. "But there is no choice. Because there is no one if we don't do that. It's our job."
Within the ministry itself, he said, "there is no idea to bring a boat for the environment."
"You know the situation now: there is no safety."
So it was left to Ms. Bachmann.
Though troubled by what she sees as the environmental depredations of the invasion — including a smoking junkyard on the banks of the Tigris just outside the concrete blast walls of the American-controlled "green zone" — Ms. Bachmann conceded that the mighty waterway of sixth-grade textbooks on Mesopotamia had not existed for a long time.
A series of dams upstream have reduced the flow in the Tigris to less than half of its historical strength, and raw sewage roars in from open pipes. There are strong suspicions that untreated medical waste is creating some of the most disgusting and dangerous stretches of the river.
"This river is an open sewer," Ms. Bachmann said, wearing a blue T-shirt from her employer at home, the Port Townsend Marine Science Center, an educational nonprofit group. She also said, "It's not as big as the mighty it used to be."
"It's been tamed and beaten," she said.
The river also has an abandoned feel, in part because one of Saddam Hussein's many personal whimsies was to have river views unencumbered by boats. While some people swim in the river, many Iraqi citizens still view it as a place to avoid.
But Ms. Bachmann's fearless ways around Baghdad have earned her the nickname "City Anna," said Hamid Alsharifi, principal of the Institute for Religious Freedom in Iraq.
"Anna is doing something different, unique," Dr. Alsharifi said. "Our children, who are the future of their country, are drinking that stinking water."
There are also countless misadventures waiting for anyone who takes a journey on the water. The day began under the Muthana Bridge in north Baghdad, as the sun rose in the mist over the river and Ms. Bachmann explained that she had promised the police that everyone who boarded her ragtag boats would be searched. "For what?" someone asked.
"I don't know," Ms. Bachmann said. "For candy bars."
Iraq being Iraq, the boats had no life vests, and a number of passengers said they could not swim. Still, the trip began promisingly until an expected escort by police boats never came. Iraqi police officers at a station on the sloping concrete banks — the riverbanks are nearly all concrete in Baghdad — waved the boats down and asserted that American troops would shoot at them if they proceeded.
Ms. Bachmann called Major Basim on her cellphone and the escort was hastily put together on the spot.
American Apache helicopters began shadowing the bobbing convoy of boats. At one point, the boats encountered members of a religious sect in ethereal white gowns re-enacting the baptism of Jesus. Elders dunked the heads of their followers in the Tigris, who sometimes took in mouthfuls of the murky water before spitting it out.
Finally, Major Basim called and said that it was too dangerous to go on.
Even Ms. Bachmann decided that she was pushing her luck, and she waved the boats to shore.
Copyright 2004 The New York Times Company