Lake Meyer IA 01-TRK-158
Winneshiek County S34T97NR9W 3 mi SW of Calmar.
- Cycle
- 2018
- Release Status
- Final
- Overall IR
- 4 - Water is impaired or threatened and a TMDL has been completed or is not needed.
- Trophic
- Eutrophic
- Trend
- Stable
- Created
- 4/8/2019 1:50:41 PM
- Updated
- 12/11/2019 1:42:23 PM
The Class A1 (primary contact recreation) uses are assessed (monitored) as “partially supported” due aesthetically objectionable conditions caused by algae blooms. The Class B(LW) (aquatic life) uses are assessed (evaluated) as “partially supported” due to eutrophic conditions and nutrient loading at this lake. Fish consumption uses remain “not assessed.” Sources of data for this assessment include (1) results of the statewide survey of Iowa lakes conducted from 2012 through 2016 by Iowa State University (ISU), and (2) information from the IDNR Fisheries Bureau.
For the 2018 assessment/listing cycle, the Class A1 (primary contact recreation) uses of Lake Meyer are assessed (monitored) as "partially supported" due to aesthetically objectionable conditions caused by algae blooms based on information from the ISU lake survey. Using the median values from these surveys from 2012-2016 (approximately 12 samples), Carlson 's (1977) trophic state indices for Secchi depth, chlorophyll a, and total phosphorus were 62, 66, and 64 respectively for Lake Meyer. According to Carlson (1977) the Secchi depth, chlorophyll a, and total phosphorus values all place Lake Meyer in the Eutrophic category. These values suggest high levels of chlorophyll a and suspended algae in the water, moderately poor water transparency, and moderately high levels of phosphorus in the water column. The data show no violations of the Class A1 criterion for pH in 12 samples. Note 1:A TMDL for nutrients and siltation at Lake Meyer was prepared by DNR and approved by EPA in 2005. Because all Section 303(d) impairments identified for the 2018 assessment/listing cycle (algae growth) are potentially addressed by the TMDL, this waterbody is placed in IR Category 4a (impaired; TMDL approved). The level of inorganic suspended solids was low at Lake Meyer, and does not suggest water quality problems due to non-algal turbidity. The median level of inorganic suspended solids in Lake Meyer (1.6 mg/L) was ranked 9th among the 138 lakes by the ISU lake survey. Data from the 2012-2016 ISU lake survey suggest a moderate population of cyanobacteria exists at Lake Meyer. These data show that cyanobacteria comprised 35% of the phytoplankton wet mass at this lake. The median cyanobacteria wet mass (15.7 mg/L) was ranked 66th of the 138 lakes sampled. The Class B(LW) (aquatic life) uses are assessed (evaluated) as “partially supported” due nutrient loading and eutrophic conditions at Lake Meyer. This BPJ-based potential impairment is not appropriate for Iowa’s Section 303(d) list of impaired waters (Integrated Report Category 5) but is appropriate for IR Category 3b of Iowa’s Integrated Report and Iowa’s list of waters in need of further investigation. Results of the ISU lake survey from 2012-2016 show there were no violations of the criterion for ammonia in 12 samples(0%), no violations of the criterion for dissolved oxygen in 12 samples(0%), and no violations of the criterion for pH in 12 samples(0%). Based on DNR's assessment methodology these violations are not significantly greater than 10% of the samples and therefore suggest (fully supported/monitored) of the Class B(LW) uses of Lake Meyer. Fish consumption uses are "not assessed" due to the lack of recent fish contaminant monitoring at this lake. The most recent fish contaminant monitoring was conducted in 1994 as part of the U.S.EPA/DNR (RAFT) program. Although results of the 1994 RAFT monitoring at Lake Meyer indicated very low levels of contaminants and “full support” of the fish consumption uses, these data are now considered too old (greater than ten years) to characterize current water quality conditions. Note 2: In 2015,Lake Meyer was lowered 10 feet to create water retention basins and in-lake habitat could be installed. In addition, sediment was removedand the dam was repaired.