16-inch sewer force main affected
On Sunday, Sept. 8, damage to an air release valve (ARV) located at 651 Jacaranda Blvd. in Venice resulted in a spill of about 7,500 gallons of sewage, Sarasota County Public Utilities staff has reported to the Florida Department of Environmental Protection (FDEP).
The ARV was on a 16-inch sewer force main, the report pointed out.
The incident began about 12:45 p.m., the report noted. A crew was not able to stop the spill until 6 p.m., the report said, as the workers had to isolate the force main to do so.
The crew recovered about 81,000 gallons of stormwater and wastewater combined, the report added.
The U.S. Environmental Protection Agency points out, “Force mains are pipelines that convey wastewater under pressure from the discharge side of a pump or pneumatic ejector to a discharge point. Pumps or compressors located in a lift station provide the energy for wastewater conveyance in force mains.”
As 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.”
Cleanup of the surrounding site and notifications to affected property owners and residents were proceeding according to county protocol, the report added. “Surface waters were impacted,” it said, so sampling would be necessary in an effort to ensure public safety.
A pond or stormwater retention area appears to stand slightly northwest of the spill site, adjacent to Jacaranda Boulevard and just east of Interstate 75, as shown on a map.