The city of Mercer Island recently distributed its 2008 Water Quality Report, which once again assured residents that Mercer Island’s water quality is above standard. The annual report, conducted each year by the city and Seattle Public Utilities (SPU), quantifies the regulated substances in Island residents’ water. It is a legal requirement for the city to publicize this data annually.

According to city Utilities Operation Manager Terry Smith, the 2008 report shows that Mercer Island’s water, which comes from the Cedar River Watershed, is some of the cleanest in Washington state.

“We’re really spoiled in this area. We have the highest quality water in the state. And if you start to go nationally, our water is pristine,” Smith said, adding that a big reason is because Seattle’s water is supplied by melting snow pack in the Cascade Mountains.

Unlike water drawn from wells deep within the earth, river and glacial water — because it runs along the surface of the earth — is much more pure. This is the difference, Smith pointed out, from the off-smelling, discolored water of some cities and the quaffable, clear water that Island residents receive.

While glacial runoff does include natural erosion deposits and chemicals found in the earth, SPU specialists thoroughly screen and purify the water to meet federal and state requirements. The Cedar treatment facility, which was completed in 2003, screens for debris, disinfects water with chlorine to remove microbial contaminants, flouridates it for dental health protection and adjusts the water with lime to minimize lead leaching in older plumbing systems.

On top of this process, water samples are tested daily for a wide range of substances.

According to 2008 data, Island tap water contains: .00015 parts per million (one part substance per million parts water or bbm) of barium; .05 parts per billion (ppb) of probate; 1.03 ppm chlorine, .8 pp total organic carbon and .4 ppm turbidity. These levels are far below the maximum contaminate numbers, which are 2 ppm for barium, 0 for bromate, 4 for chlorine, .8 for total organic carbon and .4 for turbidity.

Copper and lead were not included in the 2008 report as the elements will not be measured until this July. However, Smith is positive that these two levels will also be exemplary. The last test taken in 2006 showed that copper and lead levels in Mercer Island drinking water were .11 and 4.5, both within legal requirements.

“Over the last four years, there’s truly no differences [in water quality],” the utilities manager said.

The 2008 water quality report validates Smith’s assertion that water from the tap on Mercer Island is “without a doubt safe to drink.”

Despite the fact that many Island residents prefer bottled or filtered water, sticking your head under the faucet for a drink poses no health risk. In fact, Smith believes that tap water is often safer to drink than bottled water.

“Bottled water isn’t always tested,” he said, adding that he has several articles to back up his statement. “The cost of bottled water is extreme, compared with tap. And then all those bottles are thrown away into landfill.”

Although Smith’s opinion may not dissuade avid Evian drinkers, he stands by it firmly.

The only recent problem that Mercer Island has had with the quality of its water was during last year’s heavy rains and floods, when excessive debris was swept into the Cedar River. Yet Smith was even hesitant to call this issue a “problem,” as SPU worked diligently to ensure that Seattle residents’ water remained potable.

The 2008 Water Quality Report also touches on the subject of water conservation.

Because the Cascade Mountains saw plenty of snowfall last winter, there is little chance of a drought this summer. Yet, this should serve as no excuse for residents to squander water, Smith said.

Conservation methods include: loading dishwashers to capacity (one cycle uses an average of 15 gallons of water); checking home faucets and toilets for leaks, and turning the tap off while brushing your teeth, among other easy habits.

Considering that Mercer Island purchased 777.67 million gallons of water from SPU in 2008, the importance of conservation becomes clear. Island citizens who notice potential water leaks — for example, from a fire hydrant — are encouraged to contact the city. People with concerns about the quality of their drinking water are also invited to speak out.

For the full 2008 Water Quality Report, go to www.mercergov.org/files/cmiwater2008pdf.