Some good environmental news to report: As announced Monday morning by U.S. Rep. Lloyd Doggett and Mayor Lee Leffingwell, there has been a dramatic decline of polycyclic aromatic hydrocarbons in the sediment of Lady Bird Lake over the last few years. The decline follows the City Council's 2005-06 ban on coal tar sealants, a common commercial asphalt surfacing product. Research by both city and U.S. Geological Survey scientists over the previous several years had indicated that PAHs were accumulating in the sediments of the lake as well as nearby Barton Springs Pool, but the source was initially uncertain.
Further research pointed the finger at the sealants, which are coke-derived liquids used as protective and cosmetic sealants on asphalt, and which break down and migrate. They contain very high levels of PAHs, "an environmental health concern because several are probable human carcinogens and they are toxic to fish and other aquatic life." That's from the abstract of a report issued Monday by the USGS, which documents a 58% PAH decline in lake sediment in the eight years since the Austin ban – the first such ban in the U.S. – took effect. "The city helped solve the mystery," said USGS hydrologist Peter Van Metre, who, with his colleague Barbara Mahler, joined Doggett and Leffingwell to explain their findings.
"What started out as a local story here, in Austin," said Mahler, "turns out to have national implications." She noted that the sealants are often used in private driveways and even playgrounds – their broad availability has made them appear safe for domestic use. A similar USGS study of 40 major lakes across the country confirmed a widespread danger, said Doggett, from products "40 times more toxic than used motor oil," producing sediments "the equivalent of Superfund sites."
In a press release, Doggett summarized, "Good science can make a difference. This study is a wake-up call for policymakers. It is long past time for a nationwide coal tar sealant ban, and today's study shows that a ban can dramatically decrease the presence of carcinogens in our lakes."
Inevitably, the coal tar industry has fought back, accusing the public officials of exaggeration and the scientists of bias. Leffingwell said that when Council was considering the ban in 2005, they were heavily lobbied, but "I'm proud to say the Council stood firm," voting unanimously to ban the sealants. This week's announcement is welcome confirmation that the city – and its environmental scientists who were monitoring the pollution – were right.
There's also a local media story in the background. In January 2003, the Statesman published a highly sensationalized story – "Toxic chemicals taint Barton waters" – reporting the city's developing information about PAHs in the sediment of Barton Springs Pool. The story garbled the distinction between water and sediment, accused the city of protecting salamanders while ignoring dangers to swimmers, argued that unregulated development was irrelevant to this pollution, and postulated a nonexistent, long-extinct "coal-gas plant" as the likely source of the PAH pollution – all in all, the daily attempted to make the case that city staff and local environmentalists had effectively colluded in ignoring a major pollution crisis.
In response, the city closed the Springs for 90 days in order to confirm that there was no danger to swimmers, and then continued its research. For Barton Springs, the source was primarily an apartment complex parking lot above the pool – but as the scientists noted Monday, Lady Bird Lake gathers runoff from a myriad surrounding sources, and the sharp decline in sedimented pollution means that the sealant ban is steadily paying off.
At the Chronicle, we had plenty of fun responding to the Statesman's manufactured hysteria – another of many examples that pasting "investigative" onto a story does not mean better reporting. Our Jan. 24, 2003, faux–Statesman front page – "Toxic agenda taints Barton report" – mocked theirs, and my colleagues Mike Clark-Madison and Amy Smith explained that the daily had both overblown and skewed the story. Noted Clark-Madison, "It's certainly novel to see the daily claiming City Hall hasn't done enough for the environment. It would be cheering were the claim not so clearly tainted, just as surely as the hillside above Barton Creek."
In its coverage this week, the daily didn't recall that it had both misidentified the problem and blamed the officials who were in fact addressing it. Nevertheless – perhaps spurred by the criticism – the city's processes worked, and in the years since, more cities and a couple of states (Washington, Minnesota) have since banned the sealants, meaning some 16 million Americans now live in cleaner places – alas, more than 300 million do not.
That was partly the point of Doggett's appearance Monday – he has Doggett-ly attempted to enact a national ban on the sealants, without much prospect of success. Maybe these results will jump-start more action – if not in Congress, perhaps among more cities and states, and even in the industry, where a few companies have begun to phase in less toxic alternatives. (See Tom Ennis' blog, Coal Tar Free America: www.coaltarfreeamerica.blogspot.com.) There's much more to be done, but it's nice to see Austin, once again, leading the way.
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