The City of Myrtle Beach (SC) is on a mission. It needs to reduce the water contamination levels on its beaches.

In 1972, the Environmental Protection Agency (EPA) found that discharges from oceanfront drainage pipes posed a potential health hazard to swimmers in ocean waters. At least four scientific studies since then reached similar conclusions.

Due to lack of funding, little progress was made to get rid of seaside drainage pipes on the oceanfront until The State, one of South Carolina’s leading newspapers, chronicled surf contamination 10 years ago. In 1996, the newspaper tested water quality and found elevated levels of bacteria in seaside drain pipes and ocean-flowing tidal inlets at Myrtle Beach. In four of six samples taken, bacteria levels exceeded government-recommended levels for swimming. After that, the business community joined with the City to seek funding to improve stormwater quality and eliminate some of the outfalls on the beach. Through this effort, $25 million was assimilated to deal with the problem.

Started over three years ago, the massive project to reduce beach contamination by better managing stormwater is well underway. The total price tag could be in excess of $40 million.

"The beach is our primary natural resource, and we need to do everything we can to make it inviting for our visitors and locals," city spokesman Mark Kruea told the Sun News in an interview. "Having rainwater pipes is not an ideal situation, and removing those pipes is very expensive and time consuming."

The City has completed projects to install pipes at 25th Avenue South and 14th Avenue North that drains rainfall runoff 1,000 feet into the ocean and studies have been completed for the next two deepwater ocean outfall projects in Myrtle Beach, which will eliminate pipes on the beach around 4th and 24th Avenues North. Pipes currently drain stormwater runoff onto the beach in those and other areas.

The completion of these deepwater ocean outfalls could reduce water contamination levels in those areas this summer. In the past, heavy rains have led to flooding or drainage onto beaches, producing high bacteria levels that can cause infections in people who ingest the water, according to the South Carolina Department of Health and Environmental Control (SCDHEC).

The outfalls collect water from existing beach pipes, diverting it under the beach and over 1,000 feet into the ocean, which can prevent the high bacteria levels near the shore. The City’s first deepwater ocean outfall project at 25th Avenue South has been complete for more than two years and is performing as expected.

25th Avenue South

The Yaupon Drainage Basin includes approximately 189 acres of commercial and residential land uses. The stormwater runoff route to 25th Avenue South was through pipes that discharged directly to the beach.

Now, Myrtle Beach is conveying the stormwater runoff beyond the beach, piping it offshore 1,200 foot into the Atlantic Ocean. DDC Engineers, Inc. an engineering firm specializing in civil engineering, land surveying, planning, landscape architecture and environmental consulting developed a design using 50-year storm conditions and the installation of two 60-inch diameter pipes which will be buried under the ocean floor. In addition, several large underground junction boxes have been included in the design to create water quality improvements before the stormwater is released into the Atlantic Ocean.

This is one of the major drainage projects for the city as it budgeted over $25.5 million for this portion of the overall goal. Joining DDC on the project is Misener Marine Construction, Inc. Misener has been successfully performing similar projects for 35-years.

14th Avenue North

In March of 2003, Myrtle Beach contracted with DDC to provide design services and construction documents for two 84" pipes extending 1,200 linear feet into the Atlantic Ocean.

A dynamic wave analysis was performed by DDC’s team members to determine the design wave and hydrodynamic forces on the proposed outfall culverts and the discharge nozzles. Using data obtained from the dynamic analysis, coupled with geotechnical information of the site, a stability analysis was performed to analyze the stability, liquefaction, and design of the proposed protection (bedding and armor stone) from hydrodynamic forces created by the design wave. The design was permitted by the Army Corp of Engineers, and the South Carolina Department of Health and Environmental Control (SCDHEC) Bureau of Ocean and Coastal Resource Management. The project started in the fall of 2005 and was completed in May 2006.

North Myrtle Beach Was the First to Utilize the System

In February of 2003, The City of North Myrtle Beach worked with DDC Engineers, Inc. to implement a 72-inch ocean outfall extending approximately 1,200 linear feet into the Atlantic Ocean. This project was designed to serve the Hillside Drive watershed located at 6th Avenue South in North Myrtle Beach. The system incorporates stormwater from a 600-acre basin which had caused flooding problems on Ocean Boulevard for many years.

According to reports in the local newspapers, "no-swimming" advisories disappeared last summer on a popular stretch of this city’s beach after workers stopped a drainage pipe from emptying tainted stormwater close to shore. Just a year earlier, the state issued eight advisories against swimming near the pipe at Sixth Avenue South.

Joe Bennett, who oversees ocean water testing for Horry County cities, told the paper that removing the pipe improved beach water quality, an important issue for the Grand Strand, the state’s biggest resort. With hundreds of thousands of vacationers strolling area beaches every week this summer; the last thing anyone wants is for a tourist to get sick from impure beach water.

"I’m almost positive it made a difference," Bennett, Director of Coastal Carolina University’s environmental laboratory, said of the offshore piping project. "There was a lagoon at the bottom of that pipe that was brown, and people would get in it. It was connected to the sea, almost like a small inlet."

During the past five years, the Grand Strand resort’s biggest cities have removed about 30 percent of the 150 drainage pipes that emptied stormwater onto the seashore in Horry County (SC). In their place, work crews have installed seven long pipes that shoot rainfall runoff stormwater nearly a quarter-mile into the sea. The idea is to mix the rainwater runoff with the ocean water offshore, rather than let beach pipes contaminate the shallows where people swim.

Does it Work?

So far, the beach around Sixth Avenue South in Ocean Drive is the only spot with measurable improvements in water quality. Few of the offshore pipes have been in place long enough to tell if they will cut down on bacteria population in the surf.

"We’re hopeful this will solve all of our beachfront water-quality problems and reduce the number of advisories we have to issue," said Fred Earnhardt, a state health department regulator in a report. "We’ve seen that already in North Myrtle Beach."

Scientists don’t know if diverting stormwater offshore will kill fish and other marine life. And skeptics wonder if the bacteria sent offshore won’t simply wash back to the beach.

In 2004 — before the storm drain was removed from the beach — the state found bacteria levels above safe-swimming standards on 15 of the 39 days tested. One reading was 30 times higher than the

federally recommended safe-swimming standard.

Those drops in water quality resulted in eight advisories against swimming in the summer of 2004.

No-swim advisories are issued at major beaches when the state finds enterococcus bacteria levels between 104 and 500 colonies per 100 milliliters of water on two consecutive days. The state also will issue a warning if a single sample exceeds 500. Additionally, the state issued no-swim advisories in anticipation of heavy rains and large volumes of stormwater runoff.

Financial Challenges Remain

As is always the case, financial costs provide municipalities with additional challenges when trying to solve stormwater problems. North Myrtle Beach is funding its improvements with a special stormwater fee. Myrtle Beach is looking for other sources of money to install more offshore pipes in the future.

According to published reports, Myrtle Beach is spending about $23 million adding offshore pipes and removing beach drains. Meanwhile North Myrtle Beach is spending about $15 million on offshore pipes and beach drain removal. SLDT