Minnetonka Drinking Water Reports and Guides

Minnetonka City Water Background

The City of Minnetonka has over 260 miles of water mains, 18 deep water wells, 10 storage facilities and 8 water treatment plants.  These treatment plants deliver an average of 8 million gallons of water per day to Minnetonka’s residents and businesses.

Minnetonka City Water Hardness and Iron

Minnetonka water is rated as extremely hard with hardness ranging from 18-20gpg (grains per gallon) by the USGS. A professional-grade Water Softener or Saltless Water Softener is highly recommended to reduce hardness less to protect plumbing, water heaters, and appliances.

Minnetonka city water may sometimes contain small levels Iron and Manganese that bleed through the city’s treatment system.  This level can result in discolored water, staining, and a metallic taste and odor. If rust stains continue to occur, a Whole House Filter may be added to stop the Iron that a Softener cannot.

Minnetonka Drinking Water Quality Reports

The City of Minnetonka MN conducts regular testing and provides Annual Water Quality Reports. These reports explain the “water contaminants” and levels that have been detected:

2011 Minnetonka Water Report
2010 Minnetonka Water Report
2009 Minnetonka Water Report
2008 Minnetonka Water Report
2007 Minnetonka Water Report
2006 Minnetonka Water Report

The EPA has established two standards for additional contaminants in tap water:

MCL: Maximum Contaminant Level – The maximum allowable level of a certain contaminant, aka the “Legal Limit”
MCLG: Maximum Contaminant Level GOAL – The level where studies have found ZERO HEALTH RISKS, aka the “Health Limit”


All water contaminants meet the EPA’s “Legal Limit”. Certain water contaminants exceed the EPA’s Health Limit and have been highlighted:

Inorganic Contaminants

Inorganic contaminants include salts and metals like Hard Water and Copper. Inorganics are mostly consumed through drinking water, and most do not easily pass through skin. Carbon Filters (refrigerator and faucet filters) have virtually ZERO impact on these contaminants. Reverse Osmosis and the LINX Evolution are very effective at removing inorganic contaminants.

Contaminant Levels Found Health Limit Legal Limit Potential Effects
Arsenic 1.68 – 2.01 0 10ppb Skin damage or problems w/ circulatory systems, increased risk of cancer
Barium 0.15 – 0.17 2 2ppm Increase in blood pressure
Fluoride 0.99 – 1.3 4 4ppm Bone disease (pain and tenderness of the bones); children may get mottled teeth
Hard Water 18 – 20gpg NA NA Damage to plumbing, appliances, glassware
Iron 0 – 0.4ppm NA NA Damage to plumbing, appliances, water heaters, laundry
Nitrate 0.37 – 0.71 10 10ppm Infants below the age of 6 months who drink water containing nitrate in excess of the MCL could become seriously ill and, if untreated, may die. Symptoms include shortness of breath and blue-baby syndrome.
Sodium 10-15ppm NA NA Hypertension
Sulfates 2.98 – 28.4ppm NA NA Catharsis, Dehydration from diarrhoea

Organic Contaminants

Organic Contaminants can be from natural sources like algae, or man-made like Carbon Tetrachloride. Many organic chemicals easily pass through the skin, and make a Pureoflow, DMT Hybrid System, or Whole House Carbon Filter a good preventative tool.

Contaminant Levels Found Health Limit Legal Limit Potential Effects
Carbon Tetrachloride 0.15 – 03 0 5ppb Liver, nervous system, or circulatory problems
Trichloroethylene 0.03 – 0.1 0 5ppb Liver problems, Increased risk of cancer

Disinfectants and Disinfection Byproducts

Disinfectants are added to control bacteria. When disinfectants like Chlorine react with other water contaminants, a new class of compounds are formed called “Disinfection Byproducts. Many of these chemicals can enter the body through inhalation, absorption through skin, and through drinking water. A Whole House Carbon Filter is a good preventative tool in addition to a Drinking Water System for these compounds.

Contaminant Levels Found Health Limit Legal Limit Potential Effects
Bromodichloromethane 1.68 – 4.6 0 80ppb Increased risk of cancer, damage to liver, kidneys, and nervous system
Chlorine 0.2 – 2.8 4 4ppm Eye/nose irritation; stomach discomfort
Chloroform 6.94 – 20 5.7 80ppb Nervous system depression, increase in kidney and liver tumors
Dibromochloromethane 0.17 – 0.6 0.4 80ppb Increased risk of cancer
Dichloroacetic Acid 2.27 – 3.7 0 60ppb Irritant and corrosive to the eyes, skin and respiratory tract
Haloacetic Acids 3 – 10.4 0 60ppb Increased risk of cancer
Trihalomethanes 1.2 – 25.2 0 80ppb Liver, kidney or central nervous system problems; increased risk of cancer

Microbial Contaminants

Bacteria, Virus, and Cysts come from a variety of sources including water main breaks, sewage treatment plants, septic systems, agricultural livestock operations, and wildlife. Microbes are mainly consumed through drinking water. Carbon Filters and Water Softeners do not offer any protection against microbes, but UV Treatment and Ultrafiltration are very effective.

Contaminant Levels Found Health Limit Legal Limit Potential Effects
Fecal Coliform* 1% 0 5% Fecal coliforms and E. coli only come from human and animal fecal waste

*Upon re-testing, 0% Fecal Bacteria was detected.

Radionuclides

Radionuclides may occur naturally, or be the result of oil and gas production or mining activities. These can be inhaled, or consumed through drinking water.

Contaminant Levels Found Health Limit Legal Limit Potential Effects
Alpha Emitters 7.1 – 10.7 0 15.4pCi/L Increased risk of cancer
Combined Radium 3.7 – 5.4 0 5pCi/L Increased risk of cancer
Radon 26 – 183 0 NA Increased risk of cancer

This information was compiled from Minnetonka’s water treatment reports, the Environmental Protection Agency(EPA), Minnesota Department of Health(DOH), World Health Organization(WHO), and Environmental Working Group(EWG). Please contact us if there are any missing contaminants, or levels that differ from those outlined on this page.