Downstream of COVID-19

As a UF/IFAS extension agent I, like all my extension colleagues, receive a lot of resources about the state of the current COVID-19 pandemic. However, someone who specializes in water resources, I couldn’t envision how COVID-19 would impact those areas where I spend most of my working hours – water quality and harmful algal blooms. Recent news headlines over the last few months have led me to re-evaluate my original perception. This blog highlights the unusual ways in which the pandemic and water resources intersect, both good and bad.

Wastewater surveillance

For more than a year, scientists and wastewater utility managers have recognized the opportunity to use wastewater as a way conduct cost-effective epidemiological surveillance of the COVID-19 virus. The virus and its RNA remain stable throughout the long wastewater process from toilet, to sewer, to treatment, and can be detected in wastewater before symptoms even arise in the person. This surveillance can detect trends in COVID infections and provide municipalities the ability to anticipate COVID loads 5-10 days in advance. It’s important to note that just because viral RNA is detectable, the virus is not infectious, and wastewater is not a likely transmission route. This is good news for Florida’s marine mammals, who are having a rough 2021!

Drinking water supply

In Florida, the delta variant has led to a spike in the number of COVID cases and a heightened need for oxygen in area hospitals. Liquid oxygen, used to treat patients, is also used for the treatment of potable water, wastewater, and reclaimed water. During the water purification process, liquid oxygen is converted to ozone and used to disinfect the water and breakdown hydrogen sulfide. For some of Florida’s water treatment plants, the increased demand for oxygen to treat COVID patients has led to a shortage. This shortage is directly impacting the potable water supply. In the Orlando area, the Orlando Utilities Commission (OUC), urged residents to conserve water, including cutting back on their landscape irrigation. Nearly two-weeks after the request, residents have failed to make sufficient conservation efforts and OUC may be forced to issue a boil water notice. OUC is not unique. In Hillsborough County, Tampa Bay Water has also seen a reduction in their liquid oxygen supply. In addition to asking residents to use less water, they have responded by temporarily treating their water with sodium hypochlorite instead of liquid oxygen. They are also adjusting the mix of sourced water – groundwater, river water, and desalinated water, to adjust for the short supply. This is a trend that is likely to continue throughout the state as cases continue to rise.

Harmful algal blooms

The increased demand for oxygen has also impacted the supply chain transportation structure and the turnaround time for harmful algal bloom toxin analysis. The state of Florida has a robust harmful algal bloom (HAB) monitoring program which includes routine and response monitoring. Water samples are collected and analyzed for algae species, toxin type, and concentration. The Florida Department of Health issues public health warnings based on this data. Nitrogen gas is required for the accurate processing of HAB toxin samples in the laboratory. However, the trucks that are normally used to transport nitrogen are being used to transport oxygen for the treatment of infected patients instead. This has impacted the normal supply chain. Nitrogen deliveries are delayed and thus, so is sample processing time. This directly impacts the timeliness of public health notifications. Residents are urged to use the precautionary principle – if water looks discolored of scummy assume there are toxins. Do not drink or recreate in it, this includes pets and other animals.

These “downstream” impacts of the pandemic highlight how linked our public health system is and underscores the idea that all health is One Health.


Larsen, D.A., Wigginton, K.R. Tracking COVID-19 with wastewater. Nat Biotechnol 38, 1151–1153 (2020).

Jones, D. (2021, August 25). Couple weeks’ supply of liquid oxygen to treat your home’s water left. WFTV9.

Gannon, M. (2021, August 26). Tampa Bay Water changes water treatment process due to liquid oxygen shortage. News Channel 8.

Harada, K., Kondo, F. & Lawton, L. (1999). Chapter 13: Laboratory analysis of cyanotoxins. In: Toxic cyanobacteria in water: A guide to their public health consequences, monitoring and management. World Health Organization.


Posted: January 14, 2022

Category: , Coasts & Marine, Conservation, NATURAL RESOURCES, UF/IFAS Extension, Water
Tags: #IFASWater, COVID-19, Florida Sea Grant, UF IFAS Water Agents, Water Quality

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