The pipe that supplies most of Marco Island's water supply is deteriorating, leaving residents vulnerable to a possible emergency.
The 30-year-old ductile iron water line was laid approximately six feet under the bed of the Marco River. The pipe crosses the river, bringing water from the Marco Lakes and Henderson Creek areas to the island's North Water Treatment Plant.
Another break in the line was discovered recently — and repaired.
Divers, who also inspected and videotaped the entire line, said a span of about 400 feet of the pipe is exposed and 240 feet suspended without support above the surface. The line is also badly corroded and scouring has occurred.
The final report of the deterioration is being completed.
In case of an emergency, the Florida Department of Transportation will allow the city to connect the reuse line to the main line at the north end of the bridge. The city recently met with officials of the DOT, the agency that controls the bridge.
Marco Island City Manager Bill Moss stated in an e-mail Wednesday to island resident and retired construction executive Ray Beaufort that connecting to the reuse line "is not a solution but it can help prevent a 'crisis.' "
"We are moving forward to making provisions to interconnect between the raw water line and the 30-inch line in case something happens," Joel said.
He added that, if the main line breaks, the city could meet the water demands of the island if the irrigation system was shut down.
"When the pipe breaks, it will impact the community," Joel said. "Hopefully, we will have a solution installed before that breaks."
The city would ask all property owners to stop irrigating. It would take a few days to connect the main to the 16-inch line. Joel noted that the demand for drinking water could be supplied from the south treatment plant, but citizens would have to conserve.
"We don't envision ever having no water," he said.
The iron water main carries 80 pounds of water per square inch. The 16-inch reuse water PVC pipe attached to the S.S. Jolley Bridge is rated for 250 pounds PSI, according to Joel.
"It's not a pressure problem," he said. "It's a flow problem."
The bridge was built in 1970. Joel didn't know if the structure could hold a 30-inch water main.
The city hired TBE, the firm that is engineering a new East Winterberry Bridge, to determine if the Jolley Bridge could withstand the weight. If it can, the city would have to get DOT approval for the project.
TBE is working on a "scope" of the engineering work needed and a budget for the work. The plan should be completed within 90 days. Another engineering firm that is reviewing the city's water supply is studying non-bridge solutions for the water main.
Finding out the thickness of the existing main by sawing out a small piece is important, according to Gary Stine, principal engineer with the Hernando Florida office of HTA Companies, an engineering firm.
"More than likely, if someone hit it, it was probably leaking at a joint," he said.
A wraparound clamp is usually put around the joint to stop it from leaking.
Stine said that slip-lining the water main would reduce the carrying capacity of the pipe. Increasing the horsepower through the pipe could compensate.
Stine said the 30-inch pipe installed on the Jolley Bridge, when full of water, would weigh approximately 450 pounds per lineal foot.
"It is a significant load," he said. "Typically, people don't like to hang things on bridges because they could fall off. Maintaining the pipe once it's up is sometimes difficult, too."
He added that the original engineers probably decided to install the main under the river because it was the "path of least resistance" to get approval from government agencies.
If the city chooses to replace or reline the underwater 30-inch line, approval would be needed from the U.S. Coast Guard and the Corps of Engineers.
Another option for replacing the main is installing another under the river by directional drilling. The pipe, which comes in 50-foot lengths and is usually trucked in, would be made of high density polyethylene plastic. It lasts much longer than iron or metal pipe.
"You butt fuse it together and there are no joints," Stine added.
The cost for directional drilling would depend on if limestone exists close to the surface. Joel couldn't give an estimated for the option.
The DOT's plan to replace the bridge, but not for several years. Installing a new water main for millions of dollars on the current bridge may not make sense economically.
Beaufort thanked Moss for asking residents experienced in infrastructure to help with suggestions.
"There are people who have a lot of expertise that, I believe, could help us," Joel added.
Members of the Waterways Advisory Board are mapping the riverbed for the city in case officials decide to replace or reline the existing main.
Marco Island resident "Butch" Neylon, president of Industrial Technical Services, has worked in the water and wastewater industries for approximately 40 years. He said that many of the country's water and sewer pipes were installed in the 1970s when the Clean Water Act was established.
"Now they are wearing out and they can't afford to replace them," he said., "This is going to be a very expensive thing. We're going to end up dumping a ton of money into this."