Lopez high school senior Laura Strom and Kwiáht scientist Russel Barsh are trying to find out if the island’s well water is getting saltier.

Water with more than 250 parts per million of salt (chlorides) has an off-taste and may corrode metal pipes and cooking utensils. It can also increase blood pressure.

In the San Juan Islands, some aquifers are below sea level, and in contact with seawater at the islands’ edges. If drinking water is drawn from these aquifers faster than they are recharged from rainfall, some seawater may be sucked in. If that happens, wells grow gradually saltier, especially wells that are close to the shoreline. Wells in fractured bedrock can be affected, as well as wells in sand or gravel.

The U.S. Geological Survey tested 184 Lopez wells in 1997 and concluded that 46 percent of them were probably contaminated by seawater. Ten percent of the wells tested, most of them on the south end, were so salty that they failed EPA drinking water standards. The Geological Survey recommended water conservation measures to avoid further losses of safe drinking water on Lopez.

“As far as I can tell, there has been no significant follow-up, so we decided to take another look,” Barsh explains.

With help from Lopez High School, Strom and Kwiáht launched a Community Campaign for Safe Drinking Water to find out what had changed since 1997. All Grade 6 to 12 students, together with teachers and staff, have been invited to bring samples of their household water to the school for study. More than 60 samples have been tested so far at the high school laboratory for chlorides and other indicators of seawater intrusion. Elementary school students and teachers will join the study after the holidays.

To obtain as representative a sample as possible, Strom is asking the entire Lopez community to submit home water sample for testing. Sample bottles can be picked up at the Lopez High School office and at Lopez Library, and dropped off at the same places. Simple instructions and a short fill-in form come with each bottle and should be returned with it. Include your email address if you would like your test results sent to you.

Ask for sample bottles at Lopez School or Lopez Library the first full week of January, and look for published reports of the island-wide study at the Library in April.