RALEIGH, N.C.(WNCN) — Memorial Day is largely seen as the unofficial start to summer. As such, the beach is a top destination for those looking for their first taste of summer. There are some waters you may want to stay away from.

The N.C. Recreational Water Quality Program tests coastal waters with the goal of protecting public health. The program largely tests for enterococcus bacteria, an indicator organism found in the intestines of warm-blooded animals. In other words, they’re looking for fecal matter.

The North Carolina Department of Environmental Quality said the bacteria will not cause illness itself but its presence is correlated with that of organisms that can cause illness.

Much of the program’s 213 swimming sites are tested on a weekly basis during the swimming season, which runs from April through September.

Jockey’s Ridge Soundside Access at Nags Head has been flagged with a swimming advisory. The highest advisory level, a swimming advisory means either that enterococci levels have exceeded EPA Standards for two consecutive tests or that enterococci levels of five samples collected within 30 days exceeds EPA standards.

DEQ said the advisory is not a beach closing, nor does the advisory affect the entire Nags Head area. Signs are posted in the area advising people not to come within 200 feet of those signs. The signs warn of contamination levels that would be hazardous to a person’s health.

The state issues four levels of advisories: precautionary, no pending swimming advisory, pending swimming advisory and swimming advisory.

Several sites at beaches along the Carolina coast including Kill Devil Hills, Nags Head and Kure beach have precautionary advisories which means they are stormwater discharge areas. Much of these sites are near drain pipes.

Untreated wastewater coming from discharge areas can contain pollutants and cause adverse health effects such as diarrhea, abdominal cramps and skin infections. While swimmers are not being told to stay away completely, they should be aware of the possible risk.

To view each site and its advisory level, click here.