King County dentists have taken the lead statewide in reducing toxic mercury going down the drain and out into the environment.

Now a coalition of environmental groups, labeling a voluntary state program to cut dental mercury waste a failure, wants a statewide crackdown.

The voluntary two-year agreement, in which the Washington State Dental Association promised to urge its members to control mercury waste, comes to an end July 31. In exchange, the state Department of Ecology agreed to hold off on enforcing the law until then.

Mercury is contained in silver-colored amalgam fillings. Most of the waste is produced when old fillings are removed.

An Ecology Department count in early June showed that fewer than 15 percent of the state’s 2,600 dental offices had notified the agency they had installed the proper equipment to capture all the mercury.

“This rate is abysmal. Clearly, the voluntary program is not working,” the Toxic-Free Legacy Coalition, which consists of six environmental and health advocacy groups, wrote to Ecology on Friday. “It is unfortunate that dentists have chosen to continue to flout the law but it is now time for Ecology to begin enforcing the law.”

While the Ecology Department proposed a public education campaign two years ago, the dental association convinced the agency that a low-key campaign targeting dentists was preferable, the department says.

“We’ve had different philosophies on how to move forward,” said Darin Rice, manager of the Ecology Department’s program to reduce toxic wastes. “We wanted to have a more publicly visible message out there. The (dental) association has been a little more, I’m not sure if I’d call it nervous, but cautious.”

David Hemion, assistant executive director of the dental association, said his organization has beefed up efforts to get out the word over the last six to eight weeks. Hemion said he has heard from the companies that sell dentists the mercury-capturing equipment that there has been an uptick in sales in Washington.

“There’s increased interest, and the trend is going in the right direction,” Hemion said.

He said the 15 percent figure is almost certainly lower than the actual number of dentists who have put in the amalgam-capturing equipment, because many dentists who did so probably didn’t bother to send in a state form notifying the Ecology Department of their purchase.

King County tried a five-year program of getting dentists to fall in line voluntarily and found it didn’t work, said Elsie Hulsizer, supervisor of the county’s industrial waste program.

Only 25 out of 900 dentists with mercury in their waste stream got the equipment, she said.

Then the county set a two-year deadline that required installation of the mercury-capturing devices by July 2003.

Inspectors found that 97 percent of King County dentists complied, she said. And it had a huge payback: Levels of mercury found in King County sewage sludge dropped by about 50 percent, Hulsizer said.

Sewage sludge is often spread on farm fields. Some is put in landfills. Putting mercury in landfills is a particularly bad idea because landfills produce methane gas that can make the mercury much more liable to get into the food chain, where it can harm wildlife, said Ecology Department spokeswoman Caitlin Cormier.

The amalgam fillings at issue have been used by dentists for the last 150 years. Mercury typically makes up a little less than half of the material. Silver, tin, copper and zinc also are used.

Although some activists have expressed concern that amalgam fillings could sicken people, scientific evidence proving that the fillings are dangerous is lacking. The practice is still considered safe by major health organizations.

The cost of the mercury-capturing equipment, installed, can range from $200 to $3,000, depending on the model, according to the city of San Francisco, which is enforcing its own mercury rules. Maintenance and waste disposal runs $250 to $600 a month, San Francisco officials say. Hemion said he expects costs here to mirror those.

Hemion said he thinks many dentists are complying with the Ecology Department’s requirements and he hopes a new state survey of dentists will show that.

But Ivy Sager-Rosenthal of the Washington Toxics Coalition, one of the groups pushing the Ecology Department on the issue, was skeptical.

“The track record shows they haven’t been serious about it,” she said. “