Drinking Water Quality Report

This annual report is designed to inform you about the quality of water and services we deliver to you every day. Our constant goal is to provide you with a safe and dependable supply of drinking water. We want you to understand the efforts we make to continually improve the water treatment process and protect our water resources. We are committed to ensuring the quality of your water.

2020 WATER QUALITY REPORT FOR

STORM LAKE WATER TREATMENT PLANT

This report contains important information regarding the water quality in our water system. The source of our water is groundwater. Our water quality testing shows the following results:

CONTAM IN ANT

MCL- (MCLG)

Compliance

Date

Violation

Source

Type

Value & (Range)

Yes/No

Lead (ppb)

AL=l5 (0)

90th

3.90 (NO- 6)

2019

No

Corrosion of household plumbing

systems; erosion of natural deposits

Copper (ppm)

AL=l.3 ( 1.3)

90th

0.027 (NO-

0.030)

2019

No

Corrosion of household plumbing systems; Erosion of natural deposits; Leaching from wood preservatives

950- DISTRIBUTION SYSTEM

Chlorine (ppm)

MRDL=4.0 (MRDLG=4.0)

RAA

3.0 (2.1- 4)

12/31/2020

No

Water additive used to control

microbes

Nitrite [as N] (ppm)

I (I)

SGL

0.67 (NO- 0.67)

2020

No

Runoff from fertilizer use;

Leaching from septic tanks, sewage; Erosion of natural deposits

01- 3.7.8.11.18.0Rl9 & 14.15,20 OR4/LAB SNK

Arsenic (ppb)

10 (0)

SGL

3.20

03/16/2016

No

Erosion of natural deposits: Runoff

from orchards; Runotffrom glass and electronic production wastes

Fluoride (ppm)

4 (4)

SGL

0.608

10/02/2019

No

Water additive which promotes

strong teeth; Erosion of natural deposits; Discharge from fertilizer and aluminum factories

Sodium (ppm)

N/A (N/A)

SGL

46

01/09/2019

No

Erosion of natural deposits; Added to water during treatment process

Nitrate [as N] (ppm) 10 (I 0)

SGL

O.IO(ND-0.10)

2020

No

Runoff from fe11ilizer use; Leaching from septic tanks,

Nitrate [as N] (ppm) 10 (I 0)

SGL

O.IO(ND-0.10)

2020

sewage; Erosion of natural

Nitrate [as N] (ppm) 10 (I 0)

SGL

O.IO(ND-0.10)

2020

deposits

Nitrite [as N] (ppm) I (I)

SGL

0.12 (NO- 0.12)

2020

Runoff from fertilizer use;

No Leaching from septic tanks, sewage; Erosion of natural

deposits

Note: Contaminants with dates indicate results from the most recent testing done in accordance with regulations.

DEFINITIONS

• Maximum Contaminant Level (MCL)- The highest level of a contaminant that is allowed in drinking water. MCLs are set as close to the MCLGs as feasible using the best available treatment technology.
• Maximum Contaminant Level Goal (MCLG) --The level of a contaminant in drinking water below which there is no known or expected risk to health. MCLGs allow for a margin of safety.
• ppb --parts per billion.
• ppm-- patis per million.
• pCi/L- picocuries per liter
• N/A- Not applicable
• NO-- Not detected
• RAA- Running Annual Average
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• Treatment Technique (TT)- A required process intended to reduce the level of a contaminant in drinking water.
March II, 2021 CCR 2020 STORM LAKE WATER TREATMENT PLANT PWSID: 1178097 Page 1
This water supply obtains its water from the sandstone and dolomite of the Cambrian-Ordovician aquifer. The Cambrian-Ordovician aquifer was determined to have low susceptibility to contamination because the characteristics of the aquifer and overlying materials provide natural protection from contaminants at the land surface. The Cambrian-Ordovician well will have low susceptibility to surface contaminants such as leaking underground storage tanks, contaminant spills, and excess fertilizer application. A detailed evaluation of your source water was completed by the Iowa Department ofNatural Resources, and is available fi·om the Water Operator at 712-732-8031 .

CONTACT INFORMATION

For questions regarding this information or how you can get involved in decisions regarding the water system, please contact STORM LAKE WATER TREATMENT PLANT at 712-732-8031.

In addition, large water supplies, and a representative sample of small water supplies, have been participating

in a study with the EPA related to the Unregulated Contaminat Monitoring Rlue (UCMR). We are required to report any detects from the test run in March, 2019.

Manganese 8.00 micrograms per Liter

March II, 2021 CCR 2020 STORM LAKE WATER TREATMENT PLANT PWSID: 1178097 Page 3