Rain pelted Porter Beach Wednesday as National Park Service ranger Jana Cram made her way through the waves washing over the shore.
Within less than a minute, Cram scooped up water samples and made her way back to a pickup truck to prepare them to be tested for a toxic chemical spilled into the Burns Waterway in April by a U.S. Steel facility.
Protected from a 1-foot-deep puddle by her hip-high waders, Cram said lightning or dangerously high waves could delay the sampling but not prevent it.
“It needs to be done every Wednesday,” said Cram, a biological science technician.
The park service has collected water samples each week since just before Memorial Day to be tested for hexavalent chromium and total chromium. Concern centers on hexavalent chromium, a carcinogenic chemical that can cause skin reactions on direct contact.
None of the samples taken this year has had a concentration of hexavalent chromium above the minimum detection level of 0.03 milligrams per liter, said Charles Morris, environmental protection specialist at the Indiana Dunes National Lakeshore. The U.S. Environmental Protection Agency's standard for drinking water is 0.1 milligrams per liter, according to a fact sheet.
The chromium sampling program will continue until the Wednesday before Labor Day.
It's 'about keeping visitors safe'
Back at a lab at park headquarters, Cram set three vials — each containing water from either Porter Beach, Portage Lakefront and Riverwalk, or West Beach — in a stand.
Park staff test for hexavalent chromium the day water samples are collected. On a nearby instrument, a concentration is displayed. If the number is below the minimum detection level, it is not considered accurate, he said.
U.S. Steel has been testing water at Ogden Dunes, the site of an Indiana American Water intake. The park's testing methods are EPA-approved, but not as precise as those used by the steel company, Morris said.
"This is simply about keeping visitors safe," he said.
If park employees were to see a concerning number, they would follow up, Morris said. So far this year, testing by the park and U.S. Steel has found no reason for concern, he said.
Water samples to be tested for total chromium are preserved upon collection and tested periodically, Morris said. Total chromium does not pose the same risk to park visitors as hexavalent chromium, so immediate results are not necessary.
Chromium has many states, and hexavalent chromium tends to reduce to less harmful forms under natural conditions, Morris said. The park has been testing for total chromium to determine a baseline level, Morris said.
If there were a significant amount of hexavalent chromium out in the water, it likely would be reflected in total chromium levels, he said.
"But total chromium isn't a problem," he said. "There's so many different sources of chromium in a lake, you can't say that's their chromium or that's my chromium. It doesn't work that way."
First beach advisory of the year
The National Lakeshore agreed to assist with a long-term monitoring plan, which was submitted to EPA by U.S. Steel after the April 11 spill in Portage.
The park conducts chromium sampling in conjunction with its regular E. coli monitoring program, Morris said.
The National Lakeshore on Thursday issued its first beach advisory of the year after E. coli levels in water samples collected Wednesday at Porter Beach exceeded standards.
E. coli levels can be highly variable, but rain and clouds tend to create favorable conditions for the bacteria, Morris said. Rain can cause sewer overflows and flush creeks, pushing leakage from septic tanks into the lake.
The advisory was lifted Friday after subsequent testing showed bacteria levels decreased.
Swimmers who enter waters when bacteria counts are high face an increased risk of contracting a gastrointestinal illness.
Beachgoers are encouraged to check the Indiana Department of Environmental Management's BeachGuard website or call the National Lakeshore for the day's advisory information before heading out.