Research summary · Restorative Lake Sciences · Newaygo County, Michigan
Brooks Lake 2023 Biochar Efficacy Evaluation
Restorative Lake Sciences compared Brooks Lake water quality before and after 445 biochar filters were attached to docks and boatlifts in July 2023. Preliminary results showed lower conductivity, dissolved solids, ammonia, inorganic nitrogen and chlorophyll-a, but the report stresses that only one baseline data set exists and much more data is needed.
Biochar filters attached to docks and boatlifts, July 29, 2023
p. 7Chlorophyll-a, µg/L: baseline mean vs lowest post-biochar mean
p. 33Total dissolved solids, mg/L: baseline vs lowest post mean
p. 33Baseline data set before installation, so results are preliminary
p. 7Key findings
What the report says, step by step
Each finding is taken from the document, with page references. Charts are rebuilt from the report’s own figures.
445 filters, installed mid-season
On July 29, 2023, 445 biochar filters were attached to boatlifts and docks around Brooks Lake to reduce nutrients in the lake basin.
p. 7Algal pigment fell after installation
Mean chlorophyll-a in the north basin was 25.0 µg/L at baseline and 4.5 to 14.0 µg/L on the post-biochar dates.
p. 20, 33Dissolved solids dropped sharply
Total dissolved solids fell from a 638 mg/L baseline mean to 189 to 208 mg/L. The authors note more data is needed to tell whether biochar was the main cause.
p. 17, 33Phosphorus did not show a clear decline
Total phosphorus was 0.029 mg/L at baseline and 0.016, 0.023 and 0.034 mg/L on later dates. By November 7 most filters had been removed.
p. 33The authors call these results preliminary
Given the late installation, only one baseline data set was possible. Much more data is needed in 2024 and future years to determine the true efficacy of the biochar.
p. 7
Preliminary results indicate water quality improvements such as reductions in specific conductivity, total dissolved solids, ammonia and total inorganic nitrogen, and chlorophyll-a.Restorative Lake Sciences, Brooks Lake 2023, p. 7
About this report
Authors, date and method
- Authors
- Prepared by Restorative Lake Sciences (Jennifer L. Jermalowicz-Jones, PhD, CLP, Water Resources Director) for the Brooks Lake Association Board, Newaygo County, Michigan.
- Date
- November 2023 (as stated in the report).
- Method
- Water samples from the north basin were taken on June 23 (baseline, pre-biochar), July 28, September 20 and November 7, 2023, plus 12 sediment samples for organic carbon. Most filters had been removed by November 7.
Independent field evidence of what biochar filters do for water quality, from lake scientists at Restorative Lake Sciences. Cite the original authors when using these findings.