Update 2020-04-06: Rain and dirty Withlacoochee River again 2020-04-02
A clean river is what we like to see, and the most recent bacterial tests show the Withlacoochee River clean. You can help us keep determining when it is clean.
We haven’t seen this in more than three months: zero (0) cfu/100 mL E. coli at multiple landings on the Withlacoochee River:
Madison Florida Health Department get zero at CR 150 (near Sullivan Launch) last Thursday, and only 20 at GA 31 (State Line Boat Ramp) and at FL 6 (just above Madison Blue Spring).
Those Thursday results were even lower than good Florida results last Tuesday.
Good enough that on Thursday, Madison and Hamilton Health Departments lifted their health advisory for the Withlacoochee River.
WWALS tester Suzy Hall reported Sunday that Lowndes County had also removed its warning signs at State Line and Knights Ferry Boat Ramps. However, we at WWALS decided to wait for Suzy’s test results before deciding on our Caution signs (the yellow diamond signs).
Suzy got zero at State Line for Saturday, March 28, 2020, and at Nankin Boat Ramp for Sunday, plus only 66 at Knights Ferry Boat Ramp for Saturday. See also what do these numbers mean?
We would like to show at least Wednesday and Friday data from Valdosta, but Valdosta hasn’t posted anything on their website more recent than for Monday, March 23, 2020.
Photo: Suzy Hall, Nankin Boat Ramp, Withlacoochee River, Upstream
So we decided to remove the WWALS Caution signs, and we will do that in the next few days.
However, don’t be surprised if we put them back up after test results come in following new rains, for example the inch or more of rain that fell on Brooks County, Georgia today.
One result of all this testing is that now we know there are recurring problems, and we have a pretty good idea of the sources of the E. coli. No, it’s not Valdosta lately, and it’s probably not Quitman. It’s probably agriculture, which means it’s going to take time. We are consulting with multiple agencies and experts.
Suzy also noted an anomaly. Dissolved Oxygen (DO) was barely above 4 mg/L for all three locations she tested (Knights Ferry, Nankin, and State Line), when more typical numbers range around 7. She remarked, “I’ve never seen DO this low.”
I dug around in back data from Valdosta monthly river testing, and on March 5, 2019, Valdosta got a 3.1 DO at US 4, 3.8 at GA 133, and 4.1 at US 84. (We don’t know about State Line that day, because Valdosta didn’t test there in 2019.) The really peculiar part was Valdosta also got 2.9 DO on the Little River that same day, which could not have been because of conditions on the Withlacoochee River.
The lowest Valdosta got at the State Line was 5.6 in 2018, on both October 3 and December 19.
Farther back, all Valdosta testing stations showed low DO on 2017-09-20.
There is no obvious correlation in that back data of those DO readings with temperature, pH, Fecal coliform, or E. coli, nor even with rainfall.
WWALS Science Committee Chair Dr. Tom Potter notes that higher temperatures do reduce the amount of oxygen that can dissolve in water. However, “For nutrients to have impact there would first need to be an algae bloom followed by a die off. Bacteria could then reduce DO by degrading dead plant material.“
Suzy notes, “I do know there currently seems to be an excessive amount of brown decay on the river bed. The dynamics of it all are always so interesting!”
Dr. Potter contributed two scientific papers on the subject:
- HIGH SEDIMENT OXYGEN DEMAND WITHIN AN INSTREAM SWAMP IN SOUTHERN GEORGIA: IMPLICATIONS FOR LOW DISSOLVED OXYGEN LEVELS IN COASTAL BLACKWATER STREAMS, by M. Jason Todd, George Vellidis, R. Richard Lowrance, and Catherine M. Pringle, Journal of the American Water Resources Association, Vol 45, No. 6, December 2009.
- The Calibration, Validation, and Sensitivity Analysis of DOSag, an In-Stream Dissolved Oxygen Model, by Anna C. Linhoss, Thesis, Mississippi State University, December 2005.
Please continue to contact your local and state elected officials in Florida and Georgia to ask for funding and personnel for frequent (several times a week) testing at closely-spaced stations along all our rivers, with timely online publication. And water well testing, too.
Suzy Hall with a Petrifilm.
Each bacterial test costs $6 for Petrifilms alone, or about $8 total.
So WWALS can continue testing, WWALS Executive Director Gretchen Quarterman just bought another case of Petrifilm, to the tune of $753.25. That’s a big buy for a tiny nonprofit such as WWALS.
Maybe you want to get trained and help test; if so, follow this link.
-jsq, John S. Quarterman, Suwannee RIVERKEEPER®
You can join this fun and work by becoming a WWALS member today!