Park’s lake unaffected by the incident, county staff reports
The failure of a valve in a 24-inch sewer force main late in the afternoon of June 7 resulted in the spill of 15,000 gallons of raw sewage into a roadside swale located at 2500 Honore Ave. and into an adjacent stormwater pond, Sarasota County staff notified the Florida Department of Environmental Protection (FDEP).
The location is close to homes in The Meadows, as well as the lake at Nathan Benderson Park, where world-class rowing competitions are conducted, The Sarasota News Leader found in a review of an online map.
Mike Mylett, director of the county’s Public Utilities Department, confirmed for the News Leader that the Benderson Park lake was not affected by the spill. He said the incident site is more than half-a-mile from the lake.
Recovery efforts yielded about 10,000 gallons of combined sewage and stormwater, the FDEP report pointed out, noting that “surface waters were impacted and sampling has begun.”
Crews were able to isolate the air release valve and stop the spill, the report added.
The incident began at 4 p.m. on June 7; by 7:30 p.m., the report noted, staff had the situation under control.
The cleanup process and notifications were “proceeding according to protocol,” the report continued.
The force main is part of the infrastructure associated with the county’s Bee Ridge Water Reclamation Facility, the report added. That structure is located at 5550 Lorraine Road in Sarasota.
A sewer force main “is a pressurized sewer pipe that conveys wastewater in a situation where gravity sewage flow is not possible,” Trenchlesspedia.com points out. “Pumps or compressors push the sewage through the force main from lower to higher elevations or across landscapes where deep excavation is not feasible,” Trenchlesspedia adds.
“After the rainy season,” the FDEP report noted, the sewer force main would be shut down to facilitate the full repair of the air release valve.
In a blog, Crane Engineering explains, “Air release valves are installed at the highest points in a pipeline where air naturally collects. Air bubbles enter the valve and displace the liquid inside, lowering the liquid level. When the level drops to where it no longer buoys the float, the float drops. This motion pulls the seat away from the orifice, triggering the valve to open and vent the accumulated air into the atmosphere. As the air is vented, liquid re-enters the valve, once again buoying the float, lifting it until the seat presses against the orifice, closing the valve. This cycle automatically repeats as often as necessary to maintain an air-free system.”
Crane Engineering has offices in Wisconsin and Minnesota, its website says.