Wastewater treatment plants show omicron dominant but retreating
Wastewater samples, drawn from Orange County’s three treatment facilities and from the Altamonte Springs sewer-service area, showed decreased concentrations of COVID-19 viral fragments in testing this week, continuing a nearly 14-day, hopeful trend that suggests the worst of the omicron-variant infection surge may have passed.
“For the past week and a half, we have seen concentrations go down significantly,” said Ed Torres, director of Orange County Utilities.
The levels are still relatively high, compared to concentrations in samples drawn near Thanksgiving, but substantially less than record highs set in early January.
On Jan. 6, for instance, samples at the county’s three wastewater-treatment facilities all topped 11.5 million parts per liter with the highest measuring 18.7 million parts per liter in samples from the Northwest Water
Reclamation Facility in the Apopka area. Samples tested Monday, Jan. 17 all measured under 5 million parts per liter with the highest, 4.9 million, at the Northwest Water Reclamation Facility.
Wastewater monitoring has been used as an early-warning system for local leaders. Tests of untreated wastewater samples find viral fragments shed through stool into sewer systems.
“We now have three sampling results in a row that show substantial decrease … and that is certainly encouraging,” Torres said.
While the numbers are trending in the right direction, Torres noted the figures are still high.
“That means there’s still a lot of the virus circulating out there and omicron particularly is highly transmissible,” he said.
Lower concentrations suggest infections are dropping.
The omicron variant is the region’s dominant strain, said
Frank Martz, city manager of Altamonte Springs.
Its system serves about 78,000 people. The Orange County plants serve about 870,000 people.
In samples taken from the Altamonte Springs sewer service area on Monday, omicron was still the most common COVID-19 variant, accounting for 99.5% of COVID-19 viral genomes, according to Martz. Delta wasn’t detected in the sewage sample.
For the first time in several weeks there was a 58% decrease in the virus concentration in the Altamonte service area, which covers Altamonte Springs, Maitland, unincorporated Seminole County, Winter Park, Eatonville, and parts of Longwood.
The region is still regarded as a community with high infection transmission, based on data monitored by the Centers for Disease Control and Prevention.