Manteno Park Pond IA 06-BOY-1505

Shelby County S2T81NR40W 8 mi NW of Defiance.

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 2012 - 2014
Stream/River Water Quality Data	CY 2012 - 2014
Lake Water Quality Data	CY 2010 - 2014
Biological Sampling Data	CY 2010 - 2014*
Fish Kill Data	CY 2010 - 2014
Fish Tissue Sampling Data	CY 2010 - 2014
Continuous Dissolved Oxygen Sampling Data	CY 2010 - 2014
*Biological sites sampled in both 2009 and 2013 were also assessed.

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Cycle: 2016
Release Status: Final
Overall IR: 2 - Some of the designated uses are met but there is insufficient data to determine if remaining designated uses are met.
Trophic: Eutrophic
Trend: Stable
Created: 6/7/2016 2:42:14 PM
Updated: 7/19/2016 8:12:52 AM

Use Support

Class A1

Recreation - Primary contact

Fully Supported

Class BLW

Aquatic Life - Lakes and wetlands

Fully Supported

Class HH

Human Health -

Not Assessed

General Use

General Use water -

Not Assessed

Impairment Delistings

No delistings for this assessment cycle.

Documentation

Assessment Summary

The Class A1 (primary contact recreation) uses are assessed (monitored) as “fully supported.” The Class B(LW) (aquatic life) uses are assessed (monitored) as “fully supported.” Fish consumption uses remain “not assessed” due to a lack of information on which to base an assessment. Sources of data for this assessment include (1) results of the statewide survey of Iowa lakes conducted from 2010 through 2014 by Iowa State University (ISU), and (2) information from the IDNR Fisheries Bureau.

Assessment Explanation

For the 2016 assessment/listing cycle, the Class A1 (primary contact recreation) uses of Manteno Lake are assessed (monitored) as "fully supported" based on information from the ISU lake survey. Using the median values from these surveys from 2010-2014 (approximately 15 samples), Carlson 's (1977) trophic state indices for Secchi depth, chlorophyll a, and total phosphorus were 59, 63, and 72 respectively for Manteno Lake. According to Carlson (1977) the Secchi depth, chlorophyll a, and total phosphorus values all place Manteno Lake in between the Eutrophic and the Hypereutrophic categories. These values suggest moderately high levels of chlorophyll a and suspended algae in the water, relatively good water transparency, and very high levels of phosphorus in the water column. The data show no violations of the Class A1 criterion for pH in 15 samples.

The level of inorganic suspended solids was moderately high at Manteno Lake, and does suggest that non-algal turbidity may contribute to the impairment at this lake. The median level of inorganic suspended solids in Manteno Lake (4.99 mg/L) was ranked 87th among the 138 lakes by the ISU lake survey.

Data from the 2010-2014 ISU lake survey suggest a small population of cyanobacteria exists at Manteno Lake. These data show that cyanobacteria comprised 44% of the phytoplankton wet mass at this lake. The median cyanobacteria wet mass (5.7 mg/L) was ranked 16th of the 138 lakes sampled.

The Class B(LW) (aquatic life) uses are assessed (Monitored) as “Fully supported” based on information from the IDNR Fisheries Bureau and results from the ISU lake surveys. Information from the IDNR Fisheries Bureau suggests that Manteno Lake has rooted aquatic vegetation that provides good fish habitat and ties up nutrients that otherwise would be available for algae growth. Sediment ponds above this pond have been built providing some protection. Best management practices in the watershed to reduce sediment and nutrient from reaching the pond are very important to maintaining the water quality and the sport fishery in Manteno Park Pond. Results of the ISU lake survey from 2010-2014 show there were no violations of the criterion for ammonia in 15 samples(0%), 2 violations of the criterion for dissolved oxygen in 15 samples(13%), and no violations of the criterion for pH in 15 samples(0%). Based on IDNR'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 Manteno Lake.Fish consumption uses remain "not assessed" due to the lack of fish contaminant monitoring in this lake.

Fish consumption uses remain "not assessed" due to the lack of fish contaminant monitoring in this lake.

Monitoring and Methods

Assessment Key Dates

5/18/2010

Fixed Monitoring Start Date

8/19/2014

Fixed Monitoring Start Date

Methods

120

Surveys of fish and game biologists/other professionals

222

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

340

Primary producer surveys (phytoplankton/periphyton/macrophyton)