About a dozen customers called the Charleston Water System on Tuesday complaining about their tap water having a yellow tint, according to the utility.

The system's water is safe, despite the slightly yellow color, said Jenny Hagan Craft, the utility's public relations manager.

Craft said the calls came from customers in West Ashley, James Island and North Charleston. "There were only about a dozen calls, but it was widespread enough that we thought we should contact the media," Craft said.

The yellow color was caused by a temporary change in the water source that supplies the system's treatment plant, Craft said.

The system has two water sources, the Bushy Park Reservoir and the Edisto River.

On Monday, the treatment plant switched over to using the Edisto River source, which has water that is dark brown because of the recent rainfall, Craft said. The high amount of color is difficult to remove in the treatment process, and though it may not appear clear, the water is safe and meets all water-quality standards, she said.

The Charleston Water System expects the yellow water to clear up by this afternoon. The utility has switched back to the Bushy Park source.