End-Of-Summer Swimming And Paddling: How Safe Are Lakes And Rivers?

ACROSS AMERICA — With the end of summer approaching, many AMERICANS are squeezing in getaways to lakes and rivers for swimming, paddling and fishing.

But how safe is the water?

That question isn’t easily answered, but there are a few resources to check before heading out to the beach or launching a kayak or canoe in a river.

For starters, check for beach closing and other water quality notices posted by your county’s environmental health or similar agency, as well as the Department of Natural Resources or equivalent agency in your state.

What Are 'Impaired Waterways'?

Next, consult the Environmental Protection Agency’s inventory of impaired waterways. It includes all of the bodies of water in the United States that exceed the “total maximum daily load,” or TMDL, standards set forth in the Clean Water Act.

What does that mean?

The term relates to the amount of nitrogen and phosphorus pollution in freshwaters. The nutrients are essential for plant growth, but an overabundance of them causes algae to grow faster than ecosystems can handle, harming water quality and decreasing the oxygen fish and other aquatic life need to survive.

Common sources of excess nitrate that reaches lakes and streams include septic systems, animal feedlots, agricultural fertilizers, manure, industrial waste waters, sanitary landfills, and garbage dumps. At elevated levels, nitrates can cause severe illnesses in infants and domestic animals.

Algae blooms also allow so-called “rough fish” — carp and bullhead — populations to increase at the expense of game fish populations. Severe algae blooms result in stinky, unattractive lake water, undesirable for swimming, boating or fishing.

Nitrates added to the soil in agricultural states contribute to the infamous Gulf of Mexico “dead zone,” where fish and aquatic life can no longer survive. Freshwater is less dense than the saline seawater, so the nitrogen and phosphorus-laden runoff sits on top of the ocean surface and doesn’t mix, spurring an overgrowth of algae that consumes oxygen as the plants decompose.

The low-oxygen waters create the condition called hypoxia, and marine life suffocate and die. These waters are warmer than the deeper ocean water, further contributing to the stratification. When the waters don’t mix, oxygen in the bottom waters is limited.

Brain-Eating Amoeba: Should You Worry?

One other thing to be aware of if you're swimming in a freshwater lake, especially in warmer climates: The Centers for Disease Control and Prevention says that swimmers in freshwater lakes should assume brain-eating amoeba are present, although actual cases of infection are extremely rare.

• Related: Brain-Eating Amoeba: Assume There’s A Risk In Warm Waters, CDC Says

The organism is most often found in warm, Southern states, but a warming climate increases the likelihood of encountering the organism farther north.

In July, a swimmer at an Iowa lake died of amebic meningoencephalitis, the brain infection caused by the microscopic, single-cell, free-living amoeba, officially known as Naegleria fowleri. Earlier this month, officials in Nebraska said a child who swam in a river died of a brain-eating amoeba infection.

The amoeba enters the body through the nose only. To reduce the risk of an infection, swimmers should take precautions to prevent water from getting up their noses, such as wearing nose clips or swimming with their head above water. Beachgoers should also avoid stirring up sediment at the bottom of lakes.

Traveling? Check Out ‘Endangered Rivers’

America’s rivers aren’t the playground for canoers and kayakers they once were, according to American Rivers, which earlier this year put 10 popular rivers on its America’s Most Endangered Rivers list.

The Colorado River, which winds through parts of seven states — Colorado, Utah, Wyoming, Nevada, California, Arizona and New Mexico — tops the list.

Others on that list, ranked according to the level of endangerment, are the Snake River, once the most prolific salmon producing river in the Columbia River Basin; the Mobile River in Alabama; Maine’s Atlantic salmon rivers; the Coosa River in Georgia and Alabama; the Mississippi River that runs from Minnesota to the Gulf of Mexico; the Lower Kern River in California; the San Pedro River in Arizona; the Los Angeles River; and Tar Creek.