Longboat flushing out cause of sewer pipe spill

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The Town of Longboat Key is still investigating the cause of the sewage spill that left up to 25 million gallons of wastewater in the mangroves on the east side of Sarasota Bay.

Town consultants have been busy ever since the leak was repaired on June 30 trying to determine exactly what caused the break in the pipe.

Town Manager Tom Harmer said that the environmental consultants are providing continuous test results on water quality as well as assessing the condition of the pipe. The incident started on June 18, when a discrepancy between readings was noticed by Longboat Key and Manatee County Utility Department staff. In short, all of the wastewater generated by the entire Longboat Key population travels through the 20-inch pipe from mid-Longboat Key across the Bay and onto land in west Bradenton where it is pumped into a treatment facility. The discrepancy was between the calculated flow from Longboat Key and the received flow rate on the other end of the pipe in Manatee County.

Every day there is daily flow information and discrepancies can be caused for various reasons including maintenance work, changing of valves, as well as a leak.

Harmer said both Longboat and Manatee Utility staff discovered the leak in a heavily mangroved area on property owned by Longbar Point Developer Carlos Beruff on the west Bradenton side of Sarasota Bay.

E.T. Macaenzie, an emergency contractor hired by the town, cut a road into the mangrove area and brought in fill to build up the road and support the large front-end loaders so the broken pipe could be excavated and repaired. That repair was completed a day after the leak was found on June 30.

Harmer said the spill will likely generate the Florida Department of Environmental Protection (FDEP) to issue a Notice of Violation and the FDEP will likely provide direction on restoration or mitigation.

Harmer said the violation could include a Restorative Order and/or fines. For now, the town has been continuously testing and monitoring the water and soil for levels of contamination and bacteria and near-shore waters have not been especially impacted according to the town’s hired consultant, Environmental Science Associates (ESA), and fecal coliform has not exceeded regulated levels.


Looking forward

The incident is prompting a likely fast-forwarding of the funding and construction of another pipe to transport Longboat’s wastewater.

The existing pipe is more than 40 years old and was due to be replaced but consultants told the town that it had an additional 20 years of life and should be inspected every 5 years when they evaluated the situation in 2016 and 2017.

The town did repair some sections of the existing pipe in 2017 with a polywrap, but were told by the consultant that the pipe’s overall wall thickness was sufficient.

When asked if the 2016 consultant’s assessment was wrong or insufficient based on the recent rupture, Harmer said that the conclusion is premature and he is looking to the ESA investigation for clear answers.

The town no longer is using the consultant, Greeley & Hansen, which provided the report on the status of the pipe in 2017 that gave the town and the Town Commission confidence to defer the replacement pipe.

Harmer said previous estimates to replace the pipe were between $12-$16 million. The town has budgeted for design and permitting and has started that process.

Harmer also said the town would have to borrow funds for the cost of the new pipe and it would be repaid through a user fee on sewer customers.

The project has the possibility of being expedited in the permitting phase if the FDEP and other agencies recognize it as a priority situation. Harmer said that if there is a major break in the existing wastewater pipe, the town can only shut off the flow of sewage for a few hours and store the effluent in the lift station on the island. Beyond that, there is no other method to transport the wastewater at this time. If a new pipe is built, it would allow the existing, 40-year-old pipe, to become a redundant backup measure in case a spill or maintenance is needed on the primary pipe.

One possibility is that when a new pipe is built, the old pipe can then be slip-lined and thereby have its useful life extended. Slip-lining cannot be done without a redundant pipe, since the pipe must be used continuously at this time.

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