Driver’s damage to air release valve and contractor performing underground utility work cited as reasons for spills
Separate incidents — on July 28 and Aug. 2 — resulted in spills of about 14,000 gallons of sewage in Venice, Sarasota County Public Utilities Department staff reported to the Florida Department of Environmental Protection (FDEP).
The Aug. 3 situation resulted in 10,000 gallons of raw sewage flowing mostly onto the pavement and into a nearby stormwater structure located at the intersection of Center Road and Woodbridge Drive in Venice, that report said. “Approximately 10,000 gallons of wastewater mixed with stormwater was recovered from the stormwater structure,” the report added. “The roadway was washed down using the [county] vacuum truck.”
The clean-up of the area and notifications of nearby property owners proceeded according to county protocol, the report noted. No waterway sampling was necessary, the report added, as the crews traced the stormwater collection system and verified that “no bodies of water were affected.”
County staff was alerted to the situation at 10:20 a.m. on Aug. 2, the report said, with a call having pointed out that water was flowing out of the ground at the site. County staff was able to determine that a vehicle had run off the road and struck an air release valve (ARV) on the shoulder of the road.
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.”
A June 2020 Sarasota County report on measures being taken to improve wastewater infrastructure noted that the county has more than 900 “sewer ARVs in its force main system.” The document added, “The County implemented an ARV rehabilitation program in September 2019 to inspect, repair, or replace as needed all ARVs and upgrade associated valves, piping and hardware to stainless steel. The County has already begun adding bollards around all vulnerable ARVs,” the document pointed out.
The county crews responding to the Aug. 2 incident had the ARV problem resolved by 11:15 a.m., the FDEP report noted.
In the earlier incident, county staff was alerted at 8:40 a.m. on July 28 that a 6-inch sewer force main had been damaged by a private contractor performing underground utility work in front of the residence standing at 240 Center Road in Venice, that FDEP report said. About 4,000 gallons of sewage spilled into an open ditch along the road, the report added. County crews were able to recover approximately, 3,800 gallons, the report noted.
A sewer force main is a pipeline that conveys wastewater under pressure from a lower to a higher elevation, the Environmental Protection Agency explains.
In response to the July 28 incident, county crews isolated the damaged force main by shutting off a nearby valve, the report explained. The problem was resolved by 9:45 a.m. that day, the report added.
Clean-up and notifications of nearby property owners proceeded according to county protocol, the report said.
County staff planned to file a risk insurance claim against the contractor responsible for that spill, the report indicated.
Both of the Venice incidents involved the county’s Venice Gardens Water Reclamation Facility service area, the reports noted.