County workers contain effluent at site
On Nov. 19, a leaking shut-off valve below an air release valve (ARV) necessitated Sarasota County Public Utilities staff members’ temporary shutdown of three lift stations and the spill of approximately 3,500 gallons of sewage at the intersection of Bahia Vista Street and Keely Lane between McIntosh Road and Honore Avenue in Sarasota, staff reported to the Florida Department of Environmental Protection (FDEP).
The site is close to the traditional Amish and Mennonite community of Pinecraft.
At 10 a.m. on Nov. 19, the staff report says, workers responded to an alert about effluent bubbling up from a manhole at the intersection. Upon investigation of the situation, the report adds, they discovered the leaking valve. After they repaired it, the report continues, they were able to put the ARV back into service.
All of the sewage spilled into the manhole on site, the report says, so the workers were able to recover all of it.
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.”
High Tide Technologies explains, “A wastewater lift station is a pumping station that moves wastewater from a lower elevation to a higher elevation. The benefit of using a lift station in a sewage collection system is that it saves a substantial amount of money in excavation costs, which involves digging for sewer pipes. Sewer pipes live underground, and digging trenches is costly. Installing a wastewater lift station at certain points in a gravity pipeline system saves on front-end construction costs without sacrificing efficiency or functionality. They play an integral role in moving sewage to a wastewater treatment plant.”
Surrounding property owners and residents were notified of the Nov. 19 spill, the report adds, as clean-up of the site proceeded per county protocol.
The incident began at 10 am. and was resolved by 12:45 p.m., the report notes.