Be careful what you drink.

The Tennessee River and its many streams, Knoxville's water sources, are currently on the state's 303(d) list of water quality impairments.

While the most common impairments are sediment build up and aquatic life habitat alterations, Knoxville water is also listed with levels of E. coli, nitrogen and phosphorous.

These chemicals can come from paved surfaces' runoff along with sanitary sewer overflows and leaky septic systems. Agricultural land uses can also contribute to the problem.

Michael McKinney, UT's director of environmental studies and sustainability, explained that having an impaired stream poses a public health danger and does not legally meet certain safety criteria.

"It means that our quality of life is degraded," McKinney said. "For example, it is very dangerous to swim in the creeks, and even parts of the Tennessee River are not very healthy to drink. In some places, the fish are not safe to eat."

David Hagerman, a Knoxville storm water engineer, said litter causes a high amount of damage to the water quality.

"Litter is one of the easiest pollutants to identify since it is so visible," Hagerman said. "It is also the most senseless because it serves no purpose and could be easily stopped if every individual decided not to discard their trash carelessly. However, controlling human behavior is often harder than fixing a leaking pipe or illegal discharge."

In McKinney's opinion, a lack of education and enforcement by city and state officials contribute to impaired water quality.

"Human ignorance is always a huge problem," he said. "People need to be educated that rivers and creeks are not sewers. Also, our state needs stronger laws protecting the water and also better enforcement of the laws."

Jason Scott, an engineer for the town of Farrugut, identified economics as a major roadblock to fixing this problem. When drinking water is polluted, it takes more effort and money to treat, impacting the rate citizens pay for utilities.

"Funding for water quality programs can also be a limiting factor when some systemic fixes can cost from the tens of thousands to millions of dollars," Scott said. "That said, all the more reason to advocate for individual positive changes.

"One ounce of prevention is worth a pound of cure."

However, Hagerman said Knoxville's water quality is typical for an urban environment and always improving. He explained most urban streams are listed by the state as impaired due to bacteria.

The health risks, Hagerman said, are nothing to be overly concerned with.

"It means that we can enjoy most of our streams, but there are common sense precautions that should be observed," Hagerman said. "Don't drink creek water and avoid contact if you have open cuts, sores, etc. The Knox County Health Department is a good source for health warnings."

Knoxville water quality is regulated nationally by a Phase II National Pollutant Discharge Elimination System permit according to population, then the Tennessee Department of Environment and Conservation sets further standards while the city of Knoxville monitors storm water to identify any impacts to the receiving streams of the Tennessee River.

McKinney said adjustments to the sewer system and reduced surface run-off from the city could greatly raise the city's water quality. Techniques for achieving these changes include rain gardens and retention ponds.

"More vegetation, especially in riverbank areas, are extremely effective," McKinney said.

Scott expressed his belief that individual action affecting water quality is critical to the community as a whole.

"One person taking a small action may seem pointless," Scott said. "But if you consider that action multiplied by thousands or hundreds of thousands of people across a community, those individual actions can genuinely make a difference in water quality and the health of the community."