Orono MN Water Hardness & Drinking Water Guide

City of Orono MN Water Quality Background

The City of Orono MN provides drinking water to its residents from three wells ranging from 269-385 feet deep. These wells draw water from the Jordan, Quaternary Buried Artesian, and Prairie Du Chien-Jordan aquifers.

Orono Water Hardness

Orono water hardness ranges from 22-25gpg.  This is rated “extremely hard” by the USGS (hard water info).  A High Efficiency Water Softener or Saltless Softener can provide protection against hard water damage.

Occasional Rusty Discolored Water in Orono MN

Sometimes the tap water supplied by the City of Orono MN may contain low levels of Iron and Manganese that bleed through the treatment system.

Iron is another natural mineral in Orono water with concentrations ranging between 0-0.4ppm. In areas with over 0.3ppm, discolored laundry, stained fixtures, and a metallic taste or smell may be noticed.

Orono Drinking Water Reports

The City of Orono MN does regular water testing and publishes the results in Annual Drinking Water Reports. These reports explain which water contaminants, and what levels have been found:

2012 Orono Water Report
2011 Orono Water Report
2010 Orono Water Report
2009 Orono Water Report
2008 Orono Water Report
2004 Orono Water Report
2003 Orono 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 Water Hardness 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 2.13 – 3.0 0 10ppb Skin damage or problems w/ circulatory systems, increased risk of cancer
Barium 0.11 – .12 2 2ppm Increase in blood pressure
Fluoride 0.98 – 1.9 4 4ppm Bone disease (pain and tenderness of the bones); children may get mottled teeth
Hard Water 22 – 25gpg NA NA Damage to plumbing, appliances, glassware
Iron 0 – 0.4ppm NA NA Damage to plumbing, appliances, water heaters, laundry
Nitrate 0.41 – 0.78ppm 10 10ppm Kidney damage
Sodium 9 – 160ppm NA NA Hypertension
Sulfates 28 – 35ppm NA NA Catharsis, Dehydration from diarrhea

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 0.7 – 1.6 0 80ppb Increased risk of cancer, damage to liver, kidneys, and nervous system
Chlorine 0.6 – 0.9 4 4ppm Eye/nose irritation; stomach discomfort
Dibromochloromethane 0.23 – 0.9 0.4 80ppb Increased risk of cancer
Dichloroacetic Acid 1.43 – 2.2 0 60ppb Irritant and corrosive to the eyes, skin and respiratory tract
Haloacetic Acids 2.1 – 2.2 0 60ppb Increased risk of cancer
Trihalomethanes 1.8 – 5.6 0 80ppb Liver, kidney or central nervous system problems; increased risk of cancer

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 2.1 – 8.3 0 15.4pCi/L Increased risk of cancer
Combined Radium 2.8 0 5pCi/L Increased risk of cancer
Radon 390 – 597.50 0 NA Increased risk of cancer

This information was compiled from Orono’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.