COLUMBIA -- Contamination from a sewage spill into the lower Saluda River initially was up to 230 times the limit considered safe, tests made public Tuesday showed.
The level dropped to 32 times the maximum by last weekend as checks continue to measure how fast bacteria is dispersing.
Results from the latest tests taken Monday are pending and could be available today.
State officials for the first time called the leak a major problem, one week after they warned people not to swim in the river.
"This is a serious spill," said Thom Berry, a spokesman for the state Department of Health and Environmental Control.
"This is a body of water used for recreation by many people in an urban area. This is not supposed to happen."
Still, the findings are well short of the level of spills in other South Carolina rivers, he said.
Tests showed fecal coliform in the river was estimated as high as 92,000 colony-forming units per 100 milliliters of water July 29, the first check for the spill. The largest reading found three days later was 13,000 units.
The maximum level considered safe is 400 units.
Tests on Saturday and Sunday were skewed by storms that sent debris into the river, officials said.
Excessive levels have been found daily at three to five sites a half-mile downstream of the spill, records supplied by DHEC show.
Signs posted at the rapids near Riverbanks Zoo and Botanical Garden on July 30 warn those who go into the river that they could get sick.
Nausea and ear, eye, nose and throat infections are possible. But DHEC officials don't know of any illness reported after the spill.
State officials are investigating when the spill began and ended and how it happened.