Could there be drugs in your drinking water?

Does Rock Hill's water have antibiotics and mood stabilizers like Philadelphia and Southern California?

York County water drinkers can't know for sure.

An Associated Press investigation determined the drinking water supplies of 41 million Americans contain a vast array of pharmaceuticals, including anti-convulsants and sex hormones.

Rock Hill's utilities department monitors water from Lake Wylie into the city's Cherry Road treatment facility and to your tap. But the department only tests for substances the authorities know make people sick, such as bacteria. Like other water systems in South Carolina, Rock Hill's doesn't check for pharmaceuticals.

"I'm not aware of any pharmaceuticals to look for in the water; or if it's even a problem," said Rock Hill Utilities Director Jimmy Bagley.

He said Lake Wylie is a good source of water, and the city treats it with a chlorine product intended to reduce disease-causing substances.

State and federal standards only require municipalities to treat and test water for substances known to threaten human health, according to a statement released Monday by the S.C. Department of Health and Environmental Control.

But those tests don't include monitoring water for pharmaceutical drugs, according to DHEC. No standards exist for determining what levels of those drugs are safe or unsafe, the agency said.

Water testing

Rock Hill constantly tests its water, Bagley said. The city performed more than 3,000 tests at 146 sites in 2006, measuring for bacteria, chlorine and other substances.

The city's water met state and federal standards at the time of its most recent Consumer Confidence Report in 2006. The report stated levels of known contaminates such as nitrates, sodium, lead and copper did not exceed minimum standards.

The city's water treatment processes have been recognized by DHEC, and Bagley said the facility continues to meet minimum water quality standards set by the state and the EPA.

"We don't know of any health risks related to our water," Bagley said. "There's no need to worry about what's already naturally in the water or the level of things added to the water. I think DHEC and the EPA are on top of things. ... If they give us new standards, we'll meet them."

Chemicals used in the treatment process, other than chlorine and fluoride, are stripped before the water flows through neighborhood sinks.

The Associated Press reports pharmaceutical drugs are found in water because of the way humans digest the drugs.

The human body absorbs some of the medication, but the rest of it passes through and is flushed down the toilet. And while the water is treated at a wastewater treatment plant before it is discharged into lakes or rivers, some drug residue may remain. The water may then be treated at another drinking water treatment plant, but some residue may yet remain.

To dispose of unused medications, the state Department of Health and Environmental Control doesn't suggest flushing prescription medications in the toilet unless the label says it's OK.

Instead, the department recommends taking the drugs out of their original containers and throwing them in the trash or mixing prescription drugs with another substance, such as used coffee grounds or kitty litter, and putting them into an impermeable container such as an empty can or sealable bag before throwing them into the trash.