Beachgoers should have no worries about the cleanliness of the waters along the Hilton Head Island oceanfront. Tests indicate the water is among the cleanest along the South Carolina coast. DEAN ROWLAND

Nobody snorkels in the ocean off Hilton Head Island beaches. Currents and surf tumble the sand and silt into a murky mess with about a 10-inch visibility below the water’s surface.

But locals do know that the ocean water quality is clean – among the cleanest along South Carolina’s 180-mile coastline. Myrtle Beach and the Grand Strand in Horry County are at the back end of the water quality spectrum.

Local, regional and state government agencies regularly monitor local fresh and saltwater sources from the Atlantic to the May River in Bluffton. Except for the churning of water and high tides from the likes of hurricanes Matthew and Irma, accidental pollutant runoff from new development, stormwater breech discharges, and the resulting high counts of bacteria and other contaminants, water quality at the beaches has remained constantly good through the years.

The South Carolina Department of Health and Environmental Control (DHEC) beach monitoring program routinely samples ocean water at 123 sites from Cherry Grove to Hilton Head twice a month from May 1 to Oct. 1. Fifteen of those sites are on Hilton Head and dot the entire length of the island.

The last report, published in 2018, found that 2% of the ocean samples for Beaufort County exceeded the daily maximum of bacterial and pollutant standards.

The same percentage was recorded in 2011 and 2014. Horry County recorded 20% of sampling days with potentially unsafe waters.

“The water quality of natural water bodies can change from day to day, but current samples from the Hilton Head area show water quality levels meet state and federal water quality standards,” said DHEC public information officer Laura Renwick.

The advent of water quality awareness on the island began in the mid-1990s with public comment encouraging formal monitoring.

“There were people asking questions about what is our water quality like, how is it affected, and unfortunately there was not a lot of good data,” said Bryan Rabon, manager of Aquatic Science Programs at DHEC’s Bureau of Water.

Limited ocean water testing began in 1998, and routine sampling and swim advisories started in 2002, spurred in large part by the federal Beach Act enacted in 2000.

The Town of Hilton Head Island began supplemental water monitoring in 2007 as a backup sample to compare with the state’s findings.

Go back to 1999 and you’ll find the town has been collecting water quality data as part of a capital improvements program stormwater project. Data collected from stormwater discharge established a baseline to compare before and after construction project completion and initiated remedies to the adverse impact of water quality.

The May River is an entirely different story. This tidal river with high salinity waters, deep channels and extensive salt marshes has been challenged for its water quality for the past two decades.

The main concern has been fecal coliform bacteria coming from the river’s tributaries, which can affect the health of oysters, shrimp, crabs and other saltwater fin fish. The stream of commercial and residential development that began 15 years raised a collective red flag by residents and local government.

A collaborative multi-agency effort in 2004 established a baseline for assessing the water, sediment and biological quality of the entire riverine system based on data collected in 2002-03 prior to any major development activities in the watershed.

“The Town of Bluffton has been extremely proactive in seeking funding to perform a comprehensive study of the May River,” the report noted. Funding for the study came from the first of several Environmental Protection Agency grants regarding the May River’s health.

The baseline data enabled the town to compare future monitoring data and correct any adverse changes that might occur with development of the May River watershed.

The 2004 report found that open water habitat fared “good” in water quality, sediment quality and biotic condition; large tidal creeks fared “good” in sediment quality and biotic condition and “good to fair” in water quality; and headwater tidal creeks fared “good to poor” in all three categories.

In 2007, Bluffton adopted a stormwater ordinance and stormwater-management design manual.

The town of Bluffton and the Palmetto Bluff development each initiated regular monitoring programs in their watersheds in 2010. Town council authorized the creation of a Stormwater and Watershed Management Division in 2011 whose sole mission is to prevent pollution and restore shellfishing in the May River.

These days, the historical, cultural, economic and recreational well-being of the May River are on the positive side of a delicate ecological balance.

Lowcountry resident Dean Rowland is a veteran senior editor and freelance writer.