2024 Cynobacteria Testing in Lake Garfield
Every two weeks starting in June, Shannon Poulin has been taking water samples from our lake. See her reports below.
Lake Garfield Final Water Quality and Cyanobacteria Report 2023
September 18, 2024
On September 18, 2024, one sample was taken on the surface of the small Bowl and one at 25 feet in the Big Bowl in 30.2 feet of water. The phycocyanin levels were at 0.10 parts per billion which is extremely low for both samples. The cell counts at the surface were 900 cells/mL of Microcystis and 200 cells/mL of Dolichospermum for a total of 1100 cells/mL. The cell counts at 25 feet were 18,000 cells/mL of Microcystis. Neither location had cell counts that are near the state’s threshold, therefore the lake is safe at this time.
The temperature and dissolved oxygen were taken at 1 to 28 feet. The oxygen levels were steady for the first 20 feet then then dropped below 2 mg/L at 28 feet. The secchi disc had a reading of 11.4 feet which increased from the last sampling.
Figure 1. Estimated Lake Stratification (where 0 is the surface of the lake).
August 21, 2024
On August 21, 2024, one sample was taken on the surface of the small Bowl and one at 25 feet in the Big Bowl in 30.9 feet of water. The phycocyanin levels were at 0.10 parts per billion which is extremely low for both samples. The cell counts at the surface were 850 cells/mL of Microcystis and 100 cells/mL of Dolichospermum for a total of 950 cells/mL. The cell counts at 25 feet were 600 cells/mL of Microcystis. Neither location had cell counts that are near the state’s threshold, therefore the lake is safe at this time.
The temperature and dissolved oxygen were taken at 1 to 28 feet. The oxygen levels were steady for the first 20 feet then then dropped below 2 mg/L at 28 feet. The secchi disc had a reading of 10.9 feet which increased from the last sampling.
Figure 1. Estimated Lake Stratification (where 0 is the surface of the lake).
August 5, 2024
On August 5, 2024, one sample was taken on the surface of the small Bowl and one at 20 feet in the Big Bowl in 30.8 feet of water. The phycocyanin levels were at 0.10 parts per billion which is extremely low for both samples. The cell counts at the surface were 750 cells/mL of Microcystis and 150 cells/mL of Dolichospermum for a total of 900 cells/mL. The cell counts at 20 feet were 1000 cells/mL of Microcystis. Neither location had cell counts that are near the state’s threshold, therefore the lake is safe at this time.
Compared to previous years the lake is warmer than it was last year at the same time. The cell counts are similar to previous years.
The temperature and dissolved oxygen were taken at 1 to 28 feet. The oxygen levels were steady for the first 15 feet then increased at 20 feet, then dropped below 2 mg/L at 28 feet. The secchi disc had a reading of 9.5 feet.
Figure 1. Estimated Lake Stratification (where 0 is the surface of the lake).
July 23, 2024
On July 23, 2024, one sample was taken on the surface of the small Bowl and one at 20 feet in the Big Bowl in 30.5 feet of water. The phycocyanin levels were at 0.10 parts per billion which is extremely low for both samples. The cell counts at the surface were 800 cells/mL of Microcystis and 300 cells/mL of Dolichospermum for a total of 1100 cells/mL. The cell counts at 20 feet were 1150 cells/mL of Microcystis. Neither location had cell counts that are near the state’s threshold, therefore the lake is safe at this time.
Compared to previous years the lake is warmer than it was last year at the same time. The cell counts are similar to previous years.
The temperature and dissolved oxygen were taken at 1 to 28 feet. The oxygen levels were steady for the first 15 feet then increased at 20 feet. The secchi disc had a reading of 11.6 feet.
Figure 1. Estimated Lake Stratification (where 0 is the surface of the lake).
July 8, 2024
On July 8, 2024, one sample was taken on the surface of the small Bowl and one at 20 feet in the Big Bowl in 30.4 feet of water. The phycocyanin levels were at 0.10 parts per billion which is extremely low for both samples. The cell counts at the surface were 600 cells/mL of Microcystis and 200 cells/mL of Dolichospermum. The cell counts at 20 feet were 1200 cells/mL of Microcystis. Neither location had cell counts that are near the state’s threshold, therefore the lake is safe at this time.
Compared to previous years the lake is warmer than it was last year at the same time. The cell counts are similar to previous years.
The temperature and dissolved oxygen were taken at 1 to 25 feet. The oxygen levels were steady for the first 15 feet then increased at 20 feet. The secchi disc had a reading of 13.8 feet.
Figure 1. Estimated Lake Stratification (where 0 is the surface of the lake).
June 22, 2024
On June 22, 2024, one sample was taken on the surface of the small Bowl and one at 25 feet in the Big Bowl in 29.7 feet of water. The phycocyanin levels were at 0.10 parts per billion which is extremely low for both samples. The cell counts at the surface were 700 cells/mL of Microcystis. The cell counts at 25 feet were 500 cells/mL of Microcystis. Neither location had cell counts that are near the state’s threshold, therefore the lake is safe at this time.
Compared to previous years, Microcystis was the only cyanobacteria found this year whereas Dolichospermum and Aphanizomenon were also found. The lake is warmer than it was last year at the same time.
The temperature and dissolved oxygen were taken at 1 to 25 feet. The oxygen levels were steady for the first 15 feet then decreased below 2 mg/L at 25 feet. The secchi disc had a reading of 11.4 feet.
Figure 1. Estimated Lake Stratification (where 0 is the surface of the lake).
Taxa abrevation as follows:
Doli=dolichospermum
Micro=Microcystis
Apha=amphazamenon
Limn=Limnoraphis
Woro=woronichinia