Although the snow is finally melting, evidence of wintry weather remains on campus.

The Office of the Physical Plant (OPP) is in charge of snow removal.

It normally uses common rock salt to melt the ice on roadways and sidewalks during cold weather.

The rock salt also leaves campus streets white.

However, there are consequences for what Lloyd Rhoades, OPP manager of central services, calls the "best, most effective agent" to remove ice and snowmelt.

"We are acutely aware of the damage salt can cause," he said.

"Before we make a decision to start salting, we look at the temperatures. The salt we use is effective to 15 degrees.

"If the temperature is going to get warmer, we don't salt. We let Mother Nature do it.

"Below that temperature, we don't salt either."

Using too much salt on sidewalks and roadways can cause damage to metal surfaces and may seep into the groundwater.

"We have tried alternative products, but the ice-melting capacity is less and the cost is high," Rhoades said.

The main drainage basin for University Park campus is Thompson Run, which is part of the Spring Creek watershed.

ClearWater Conservancy is a volunteer-based organization that monitors the watershed.

Once a month it takes samples of various areas in the watershed to test water quality.

One of the components they test for is the level of sodium concentration in the water.

"[Salt content] was second-highest in Thompson Run, the Penn State component of the Spring Creek watershed," said Katie Ombalski, watershed coordinator for ClearWater Conservancy.

She stressed that they do not know where it comes from.

"The highest months [in salt concentration] this year were January, February, and August," Ombalski said.

Though salt levels are usually highest in winter months, other factors can also contribute to test results.

Rhoades said OPP has supervisors who check to make sure salting crews are using only the minimum amount necessary to make the area safe for people.

However, there is little university-sponsored effort to check salt concentrations.

"I'm sure they monitor the water for drinking," Paul Ruskin, OPP spokesman, said.

"I just don't know who does it."

ClearWater Conservancy tracks results of water tests in the Penn State section of the watershed .

"There has been an increase since 1999-2001, slight each year, but there has not been an investigation as to why that is," Ombalski said.

William Sharpe, professor of forest hydrology, said salting roads makes a difference in potential drinking water, which affects people's health.

"Sodium chloride is bad for high blood pressure," he said.

Sharpe added that the American Heart Association has recommendations as to the best allowable sodium chloride concentrations in drinking water.

The tests of Thompson Run have shown concentrations above the recommended levels, but that is before the water is treated.