About 340,000 gallons of sewage flows into storm drain leading to Whitaker Bayou, following Aug. 26 failure of City of Sarasota utility equipment

Hydrogen sulfide gas build-up caused pipeline problem at lift station south of Eighth Street

On the night of Aug. 26, approximately 340,000 gallons of sewage entered a storm drain that leads to Whitaker Bayou, following a break in a sewer force main at a City of Sarasota lift station, the city has reported to the Florida Department of Environmental Protection (FDEP).

“The area was hosed down, treated with lime and vacuumed using the Vac Truck,” the report added.

Whitaker Bayou, which stretches across 1.3 miles in the northern area of the county, is part of the Sarasota Bay watershed, the county’s Water Atlas says.

“The public is advised to avoid contact with water in the Whitaker Bayou until further notice,” a city news release stressed. “Health advisory notices were placed at the location of the spill by the Department of Health-Sarasota County,” the release added.

City crews began collecting water samples from the city’s stormwater drainage system Saturday morning, the release noted. “Water in the stormwater system will be monitored until water quality returns to natural background levels. Results of samples collected on Sunday indicate water quality is approaching [those] levels,” the release pointed out.

The Environmental Protection Agency (EPA) explains that a force main is “used to convey wastewater from a lower to a high elevation, particularly where the elevation of the source is not sufficient for gravity flow …” The land throughout Sarasota County is consistently low, necessitating the use of lift stations in the city and county utility systems.

When city Utilities Department crews arrived on the site of the Lift Station 40 incident, the FDEP report said, they were able to isolate the affected 16-inch sewer force main and then re-route the flow to the city’s wastewater treatment plan on 12th Street in Sarasota, using a smaller force main.

No interruption in service occurred, the release noted.

The city’s Utilities Department was alerted to the incident at 9 p.m. on Aug. 26, the FDEP report continued. Crews completed their work by 11:30 p.m., the FDEP report added.

The Aug. 29 city news release said that the pipe was placed back into service early Saturday afternoon; “cleanup was complete by late Saturday evening.”

According to the FDEP map, Lift Station 40 is located south of Eighth Street, between North Shade Avenue and Seeds Avenue.

In their investigation of the cause of the incident, the FDEP report continued, crews discovered that a portion of the top section of the 16-inch pipe had deteriorated from hydrogen sulfide gas and failed. Crews were able to remove the damaged section of pipe and were replacing it with a new section, the release said.

The U.S. Occupational Safety and Health Administration (OSHA) points out that hydrogen sulfide also is known as sewer gas and swamp gas. Although it is colorless, it has a “pungent ‘rotten egg’ odor at low concentrations,” OSHA explains. “It is extremely flammable and highly toxic.”

In the city news release, Utilities Department Director Bill Riebe explained, “Examination of the pipe revealed the pipe ruptured due to corrosion, which is somewhat unusual given the age of the pipe.” He added, “The pipe was installed approximately 45 years ago. The expected lifespan of similar pipelines is approximately 70 years,” Riebe noted. “The rupture certainly was unexpected.”

To determine whether the corrosion was isolated to the failed section, Utilities Department technicians and engineers are evaluating the entire pipeline, the release said. Depending on the results of the evaluation, additional sections or the entire pipeline will be replaced, the release added.

“The City Commission is committed to providing reliable wastewater service and to the protection of public health and safety,” said City Manager Marlon Brown in the news release. “The Commission proactively approved a long-range plan in 2019 to invest in the renewal and replacement of the of the City’s aging water and sewer infrastructure,” Brown added in the release.

“Whereas this particular pipe rupture was unfortunate and premature,” he continued, “the City’s efforts to update its infrastructure have reduced the number and magnitude of similar events.”