DHEC to swimmers: Stay clear of harmful algal blooms this summer

COLUMBIA, S.C. (WCBD) – South Carolina’s lead health agency is monitoring state waterways for harmful algal blooms and warns swimmers to ‘stay clear’ of possible blooms in ambient surface waters. this summer.

The South Carolina Department of Health and Environmental Control said algal blooms exist in natural bodies of water almost everywhere and are not unique to South Carolina.

Blooms happen when tiny plant-like organisms called algae and cyanobacteria overgrow in rivers, lakes, and oceans. They can be associated with foam, scum, or thick layers of algae on the surface water.

DHEC says these booms can look and smell bad. They say some algal blooms are formed by toxic organisms that affect the health of people, animals, and the environment – they are called “harmful algal blooms” or HABs.

“Harmful algal blooms are more likely to occur in the summer months when temperatures are warmest,” said Bryan Rabon, manager of DHEC’s Aquatic Science program with the Bureau of Water. “You can’t tell if an algal bloom is harmful just by looking at it, and some blooms can’t be seen because they stay at the bottom of a water body until they’re disturbed.”

Rabon said a good rule of thumb is, “if you suspect an algal bloom, keep yourself and others, and pets, away from it and enjoy the water in another area where the bloom isn’t present.”

DHEC is currently monitoring two waterbodies in the state for HABs:

• An algal bloom on a portion of Lake Whelchel in Cherokee County has exceeded the state’s water quality standards for microcystins, a type of toxic cyanobacteria. The Gaffney Board of Public Work’s (GBPW) issued a water quality advisement on June 29 and posted signs around the lake. DHEC is working with local officials as the agency continues to monitor this potential HAB.
• An extensive bloom of Lyngbya wollei is located in multiple areas on Lake Wateree, located in Kershaw, Fairfield, and Lancaster counties, however, there are currently no exceedances of the State Algal Toxin standards in these areas. Lyngbya has been proven to produce toxins, and this type of algae produces a mat of material on the bottom of the lake that can float to the surface, and it’s been found to be thickest in the shallower coves of the lake. 

“There’s always a potential risk that bacteria or other organisms could make you sick when you’re swimming in natural waters because they aren’t sterile environments,” Rabon said. “That doesn’t mean you shouldn’t enjoy our lakes, rivers and beaches, it just means you should be informed and heed any signs that are posted that notify the public of any current water quality concerns detected by the agency as part of our routine ambient water monitoring.”

DHEC said it tests ambient water across South Carolina on a monthly basis year-round while ocean-facing beaches are tested weekly during the summer months – May 1 through October 1.

Statewide water sampling stations can be viewed on DHEC’s S.C. Watershed Atlas. 

According to DHEC, if a waterbody looks discolored, has a foul odor, noticeable algal mats, or dead fish or other animals, you should not enter the water or allow pets or animals near that water.

Algae blooms can be very fast-growing and become an issue before DHEC has been made aware of them. 

If you or your pets encounter waters that possibly contain a HAB, immediately rinse with tap water and try to not let pets lick themselves before they’re rinsed off. Seek immediate medical attention if illness occurs, for humans or pets.