Belva Deer Lake IA 03-NSK-6241

approximately 5 miles NE of Sigourney (T76N R11W Secs 21 16 17 Keokuk Co. )

Open Data Collection Period Modal

For purposes of developing stream/river water quality assessments for integrated reporting, three years of water quality data are typically used for both conventional pollutant parameters (e.g., indicator bacteria) and the less frequently monitored toxic parameters (e.g., toxic metals). Since the 2004 IR cycle, DNR has used a three-year data gathering period for streams, rivers, and beaches. For most assessments, the use of three years of data increases the number of samples upon which the decision on use support is based and helps address the problem of weather-related year-to-year fluctuations in water quality.

Due to the lower sampling frequency in Iowa’s ambient lake, biological, fish kill, and fish tissue monitoring programs, five years of data are used for developing IR assessments and for identifying Section 303(d) listings.

Data Type	Data Timeframe
Beach Sampling Data	CY 2014 - 2016
Stream/River Water Quality Data	CY 2014 - 2016
Lake Water Quality Data	CY 2012 - 2016
Biological Sampling Data	CY 2012 - 2016*
Fish Kill Data	CY 2012 - 2016
Fish Tissue Sampling Data	CY 2012 - 2016
Continuous Dissolved Oxygen Sampling Data	CY 2012 - 2016
*Biological sites sampled in both 2011 and 2015 were also assessed.

Open Segment Map
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Cycle: 2018
Release Status: Final
Overall IR: 1 - All designated uses are met.
Trophic: Eutrophic
Trend: Declining
Created: 1/30/2019 3:33:10 PM
Updated: 5/23/2019 1:00:07 PM

Use Support

Class BLW

Aquatic Life - Lakes and wetlands

Fully Supported

Class HH

Human Health -

Fully Supported

General Use

General Use water -

Not Assessed

Impairment Delistings

No delistings for this assessment cycle.

Documentation

Assessment Summary

Belva Deer Lake is not designated for Class A1 uses in the Iowa Surface Water Classification. The Class B(LW) (aquatic life) uses are assessed (monitored) as “fully supported.” Fish consumption uses are “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), (2) information from the IDNR Fisheries Bureau and (3) IDNR fish tissue monitoring.

Assessment Explanation

For the 2018 assessment/listing cycle, the Class A1 (primary contact recreation) uses of Lake Belva Deer are assessed (monitored) as "fully supported" based on information from the ISU lake survey. Using the median values from these surveys from 2012-2016 (approximately 15 samples), Carlson 's (1977) trophic state indices for Secchi depth, chlorophyll a, and total phosphorus were 59, 61, and 58 respectively for Lake Belva Deer. According to Carlson (1977) the Secchi depth, chlorophyll a, and total phosphorus values all place Lake Belva Deer in the Eutrophic category. These values suggest moderately high levels of chlorophyll a and suspended algae in the water, relatively good water transparency, and relatively low levels of phosphorus in the water column. The data show 2 violations of the Class A1 criterion for pH in 15 samples (13%).

The level of inorganic suspended solids was low at Lake Belva Deer, and does not suggest water quality problems due to non-algal turbidity. The median level of inorganic suspended solids in Lake Belva Deer (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 Belva Deer. These data show that cyanobacteria comprised 89% of the phytoplankton wet mass at this lake. The median cyanobacteria wet mass (16.3 mg/L) was ranked 65th of the 138 lakes sampled.

The Class B(LW) (aquatic life) uses are assessed (monitored) as "fully supported." Information from the DNR Fisheries Bureau indicate that this lake has excellent water clarity This lake has curlyleaf pondweed, however, it has not affected the fishery. Results of the ISU lake survey from 2012-2016 show there were no violations of the criterion for ammonia in 15 samples(0%), no violations of the criterion for dissolved oxygen in 15 samples(0%), and 2 violations of the criterion for pH in 15 samples(13%). 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 Belva Deer

Fish consumption uses were assessed (monitored) as “fully supported” based on results of U.S. EPA/DNR fish contaminant monitoring atLake Belva Deerin 2016. The sample of shoulder muscle from Snapping Turtle had low levels of contaminants. Levels of primary contaminants in the sample of Snapping Turtle shoulder muscle was mercury: 0.06 ppm in 2016. The existence of, or potential for, a fish consumption advisory is the basis for Section 305(b) assessments of the degree to which Iowa’s lakes and rivers support their fish consumption uses. The fish contaminant data generated from the 2016 sampling conducted at thisshow that the levels of contaminants do not exceed any of the advisory trigger levels, thus indicating no justification for issuance of a consumption advisory for this waterbody.

Monitoring and Methods

Assessment Key Dates

5/22/2012

Fixed Monitoring Start Date

8/24/2016

Fixed Monitoring End Date

8/6/2015

Fixed Monitoring Start Date

Methods

222

Non-fixed-station monitoring (conventional during key seasons and flows)

340

Primary producer surveys (phytoplankton/periphyton/macrophyton)