A six-year long study along the Waccamaw River show some areas with high level of pollutants and low-oxygen.
The Waccamaw River Quality Data study is headed by scientists at Coastal Carolina University who analyze river samples collected at 12 stations along the river twice a month.
"Some places are better than others, and some times are worse than others," said CCU's Waccamaw Watershed Academy Director Susan Libes.
Volunteers monitor stations near Whiteville, NC downstream to Georgetown.
The problem spots along the river are the Sterrit Swamp, Conway and Sampit near Georgetown.
Libes called these areas with higher than above average levels "absolutely" normal.
"Some locations are more routinely affected than other locations," said Libes. "But without monitoring at a large number of sites, we wouldn't know which locations and which times there are."
To see the data collected by researchers and check the water quality near you, click here.
Libes said these problem areas correct the levels through a natural process but often see higher levels after rainstorms.
"What it is showing is that we do have some increases that we do need to be watchful about," said Waccamaw Riverkeeper Christine Ellis.
The study tests for PH levels, E. Coli and Nitrates along with other factors that attribute to water quality.
"These are locally based impacts, and we can only know locally how to improve water quality," said Libes.
Researchers will continue to collect water samples. In hopes that in four more years, they'll know what's causing the problem and how they can fix it.