CRAWFORD AND VERNON COUNTIES - The farmers of the Tainter Creek Watershed Council (TCWC), in a watershed located in northwest Crawford County and southwest Vernon County, sampled 49 wells in the watershed in late October. General, non-well-specific results of the testing will be the subject of a public presentation by the UW-Stevens Point Center for Watershed Science and Education (CWSE) on Monday, Dec. 10 at 7:30 p.m. in the Franklin Town Hall at Liberty Pole.
The results of the 2018 surface water sampling in the watershed will not be reported at this meeting as previously announced.
Individual well test results are completely confidential and will not be discussed at the public meeting. Those who had their wells tested received their results last week. Along with the results, they received instructions about how to obtain more information about their results.
Interpretation
TCWC offered their members two of the three tests that CWSE offers. The two tests conducted were the Homeowner and Metals tests.
The ‘Homeowner’ is the basic package. This package includes the two most important tests to perform regularly on a rural well–bacteria and nitrate.
CWSE’s website says you should consider the ‘Metals’ package if you have never had your well tested for arsenic, you are experiencing problems with staining, previous tests indicated the presence of arsenic, or your plumbing system has components that contain copper or lead.
Bacteria – Coliform:the result will either be ‘absent’ or ‘present.’ An ‘absent’ result means no coliform bacteria are present, and no further action is needed at this time. A ‘present’ result means that coliform bacteria are present, and the water supply is considered bacteriologically unsafe. Well owners will need to suspend use of the water, and research the source of the contamination.
Total hardness:hardness measures the amount of calcium and magnesium in water. It is primarily caused by water slowly dissolving rocks that contain calcium and magnesium. There are no health concerns associated with drinking hard water, but it is often considered undesirable because it can cause lime buildup (scaling) in pipes and water heaters. Values near 150 mg/L (milligrams per liter) are generally ideal from an aesthetic viewpoint – a result less than 150 is considered soft water, and a result greater than 200 mg/L is considered hard water.
Alkalinity:alkalinity is a measure of water’s ability to neutralize acids. It results primarily from dissolving limestone or dolomite minerals in the aquifer. Alkalinity and total hardness are usually nearly equal in concentration because they form from the same minerals. If alkalinity is much greater than total hardness, it may indicate that the water has passed through a water softener. If alkalinity is much less than total hardness, it may signify elevated levels of chloride, nitrate or sulfate. A ‘low’ result (less than 150 mg/L) is more likely to be corrosive. A ‘high’ result (greater than 150 mg/L) may contribute to scaling.
Conductivity:conductivity is a measure of the ability of water to conduct an electrical current. It is related to the amount of dissolved substances (or ions) in water, but does not indicate which minerals are present. It is measured in ‘umhos/cm at 25 degrees Centigrade), and is typically about twice the number of total hardness. This is a test for overall water quality. If conductivity is much greater than two times the hardness, it may indicate the presence of other ions such as chloride, nitrate or sulfate, which may be human-influenced or naturally occurring.
pH:The pH test measures the concentration of hydrogen ions in a solution, which determines if a solution is acidic or basic. A change of one pH unit signifies a 10-fold change in acid level. The lower the pH, the more corrosive water will be. Typical groundwater pH values in Wisconsin range from 6.5 to 8.5.
Saturation Index:the saturation index is a measure of water’s ability to corrode or form scale. It is calculated using values from pH, alkalinity, total hardness and conductivity tests. A negative value indicates that water is likely to be corrosive, while a positive value indicates a tendency for scale. Values between zero and one are considered desirable.
Nitrogen-Nitrate:nitrate is a chemical commonly found in agricultural and lawn fertilizer. It is also formed when waste materials such as manure or septic effluent decompose. The natural level of nitrate in Wisconsin’s groundwater is less than one mg/L. Elevated nitrate levels can be an indicator of other potential contaminants. If nitrate levels are elevated, testing for pesticides may be indicated if they are used nearby. Infants less than six months of age should not drink water (or formula made with water) that contains more than 10 mg/L of nitrate-nitrogen. If feed is also high in nitrate, problems for livestock may occur if the concentration of nitrate in well water is between 20-40 mg/L.
Chloride:in most areas of Wisconsin, chloride concentrations are naturally low. Higher concentrations usually indicate contamination from septic systems, road salt, fertilizer, animal waste or other wastes. Chloride is not toxic, but some people can detect a salty taste when high levels of chloride are present. Water with high chloride may also have elevated sodium content, and may also speed up corrosion in plumbing. Levels less than 10 mg/L are desirable, and levels higher than 250 mg/L may cause a salty taste and be a potential concerns for individuals on physician prescribed ‘no salt diets.’
Arsenic:arsenic occurs above health standard in parts of the state, especially in Outagamie and Winnebago counties, and has been detected in every county in the state. The health standard is 0.010 mg/L, and can cause cancer of the skin, liver, kidney and bladder.
Calcium:calcium occurs naturally in groundwater in the state where soils or underground rock formations contain limestone or dolomite. Depending on the levels present, it can contribute to the overall dietary need for the mineral. There is no toxic effect, and calcium from diet is essential to bone health and tooth development, blood clotting, muscle contraction, nerve transmission, and may also reduce risk of heart disease.
Copper:copper is not found naturally in state water, but can be found in toxic amounts when naturally corrosive or acid water or artificially softened water is distributed in the home through copper pipes. Levels above 0.5 mg/L may affect livestock health, and copper is also toxic to fish.
Iron:iron is a naturally occurring trace mineral which can cause taste problems and discoloration of water when over 0.3 mg/L. High values can be associated with acid water or water lacking oxygen.
Lead:lead is not naturally occurring in state water at levels of health concern. It is found in water systems with brass fixtures, lead pipes or lead solder, especially when water is soft or corrosive. If lead concentration is above 0.015 mg/L, run water for several minutes before using for drinking or cooking.
Magnesium:magnesium occurs naturally in state water, and can be protective against heart disease, maintaining normal heart rhythm, and is necessary for proper calcium and vitamin C metabolism.
Manganese:concentrations greater than 0.05 mg/L can cause black or dark brown particles to form in water. Many years of exposure to levels of manganese in drinking water above 0.300 mg/L may cause harm to the nervous system.
Potassium:levels of potassium are normally less than five mg/L in state groundwater. Levels greater than 10 mg/L may indicate contamination from animal waste, unless potassium chloride is being used as a water softener salt. Some studies suggest that high potassium diets reduce the rise in blood pressure related to high sodium intake.
Sodium:natural levels of sodium are less than five mg/L in state groundwater except in some areas of eastern Wisconsin where groundwater is drawn from deep sandstone layers. It is often found at elevated levels in groundwater from road salt or septic system effluent. Sodium is associated with increased blood pressure in susceptible individuals. The US EPA and American Health Association recommend less than 20 mg/L in drinking water for individuals on a physician prescribed ‘no salt diet.’
Sulfate:sulfate is naturally occurring in groundwater in some parts of the state. Concentrations over 250 mg/L may give water an off taste and cause diarrhea symptoms in people not accustomed to consuming the water. Sulfate levels over 500 mg/L lower milk production and butterfat production in dairy cows.
Zinc:levels of zinc in state groundwater are normally less that five mg/L. Zinc is toxic to fish, and concentrations higher than one mg/L usually occur only when corrosive water is distributed through galvanized pipes, or in zinc mining areas in southwestern Wisconsin.
Regional initiatives
With water quality top-of-mind for many state residents, groundwater-testing initiatives are popping up all over southwest Wisconsin.
The LaCrosse County Public Health Department recently released their report about likely sources of nitrate contamination in wells in Holland and Onalaska townships.
Grant, Iowa and Lafayette counties have embarked on a multi-year water testing initiative as well.
Vernon County Conservationist Benjamin Wojahn has also proposed that a program of well water testing be included in the county’s 2019 budget.
Southwest Wisconsin’s sensitive karst geology is shared in common with areas in the eastern part of the state that were recently put under a ‘sensitive area’ revision to the state’s nutrient management rule, NR 151. Eleven counties were covered under the new rule, but counties in the western part of the state were not. This has some Southwest Wisconsin residents concerned that the western part of the state could be vulnerable to the same kind of groundwater contamination that residents in Kewaunee County have experienced.
