Fairfield Reservoir 2 IA 03-SKU-910

Alternate name(s) for this segment: Pleasant Lake | Fairfield Municipal Reservoir 2

Jefferson County SE 1/4S24T72NR10W near Fairfield.

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 2020 - 2022
Stream/River Water Quality Data	CY 2020 - 2022
Lake Water Quality Data	CY 2018 - 2022
Biological Sampling Data	CY 2018 - 2022*
Fish Kill Data	CY 2018 - 2022
Fish Tissue Sampling Data	CY 2018 - 2022
Continuous Dissolved Oxygen Sampling Data	CY 2018 - 2022
*Biological sites sampled in both 2017 and 2021 were also assessed.

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Cycle: 2024
Release Status: Final
Overall IR: 4 - Water is impaired or threatened and a TMDL has been completed or is not needed.
Trophic: Unknown
Trend: Unknown
Created: 11/1/2023 8:12:59 AM
Updated: 1/5/2024 2:03:43 PM

Use Support

Class BLW

Aquatic Life - Lakes and wetlands

Not Supported

Sedimentation/Siltation

Support Level

Not Supported

Impairment Code

4a - Pollutant-caused impairment. TMDL has been completed.

Cause Magnitude

Moderate

Status

Continuing

Source

Unknown: Source Unknown

Source Confidence

N/A

Cycle Added

2012

Impairment Rationale

Adverse impacts on plant/animal communities

Data Source

TMDL monitoring: Iowa DNR

Class C

Drinking Water -

Not Assessed

Class HH

Human Health -

Not Assessed

Impairment Delistings

No delistings for this assessment cycle.

Documentation

Assessment Summary

The Class BLW use remains "not supported" due to siltation impacts. All other designated uses were “not assessed.” Note: A TMDL for siltation in this lake for the aquatic life use impairment was prepared by DNR and approved by U.S.EPA in 2001.

Assessment Explanation

Class BLW:

The Class BLW aquatic life use remains assessed (evaluated) as "not supported" due to siltation impacts. Because a TMDL for siltation impacts at this lake was prepared and approved, the Class BLW use remains in Category 4a (TMDL approved) of Iowa’s Integrated Report. This lake is not part of Iowa’s ambient lake water quality monitoring program of 132 Iowa lakes.

Class C - No Data

Class HH - No Data

Monitoring and Methods

Assessment Key Dates

8/28/2001

TMDL Completed

Methods

175

Occurrence of conditions judged to cause impairment