Longboat Key estimates sewage spill was much smaller than amount reported to state
Timothy Fanning
LONGBOAT KEY — An independent consultant has reduced the estimated amount of raw sewage that spilled near Sarasota Bay in June to 11 million gallons, as opposed to the original estimate of nearly 26 million gallons.
That’s according to a draft preliminary report from the Berkeley Research Group that is still investigating what caused the Town of Longboat Key’s main sewer line to break around June 17.
Berkeley’s estimation is lower than the Florida Department of Environmental Protection’s initial estimate of 17 million gallons.
“Estimates of volume through irregular openings is not an exact science,” BRG engineer Donald Olsmstead wrote in the report. “The flows calculated herein should be considered as a reasonable estimate subject to modification based on unknown or additional information or materials not considered at the time of the estimate.”
The preliminary report did include one reason for the estimated change:
The volume through the two irregular-shaped holes (about 22 inches) in the pipe was apparently blocked by a 6-inch diameter log or a root, the report found.
Town Manager Tom Harmer indicated in a news release that the preliminary report is subject to internal and external peer review before it is finalized.
The report did not indicate what might have caused the break in the town's only force main sewer line — which runs underneath Sarasota Bay to one of Manatee County’s wastewater treatment facilities on the mainland.
The town maintains that the leak wasn’t detected until around June 29 because staff assumed low-flow rates being reported to the town by the county was due to maintenance.
Shannon Herbon, a spokeswoman for DEP, said the state has not yet decided on any possible penalty to levy in connection with the spill. However, Hebron indicated that the proposed consent order will be available soon.
It’s unclear how much the town will owe. Any fines incurred against the city will come from the town’s utility fund, which is funded by rate payers.
The draft consent order gives Longboat an opportunity to hash out fines and future actions and to address whether the government can implement capital projects to help offset any penalties.
The sewage break already has cost the town $242,454, records show. The figure does not include Longboat’s ongoing legal costs.
The town’s sole sewage line, built in 1973, was inspected in 2016 and given at least 20 years of service life.
The pipe collects sewage from the entire town and pushes it east from a pumping station on Gulf Bay Road underneath Sarasota Bay to a treatment facility in Bradenton.
Longboat is in the process of building a redundant pipeline that would run alongside or near the existing pipe. A contractor is working with both DEP and the U.S. Army Corps of Engineers to seek expedited permitting.
The timing of the actual construction of the redundant line will be determined based on the results of the permitting process and funding strategies.
Town commissioners are considering three options for a “dry line” installation on the mainland of Manatee County. That would cost between $860,000 and $2.51 million.
The town intends to advance the project as soon as possible and seek outside funding to support the project without ratepayers having to bear the full and immediate financial burden of the project.
However, to some degree, this scenario may be unavoidable, records show.
Town staff will be working with a rate consultant to determine the impacts to rates to advance the project into the five-year program and take on the additional debt service.
Longboat and Manatee County are also working to enhance the monitoring of its current wastewater system, records show. That includes the county installing three new alarms and a data-acquisition system. The county has also replaced its flow meter and is in the process of building a new one.