Uranium and Fluoride Advisory
WATER TESTING REQUIREMENTS AND RECOMMENDATIONS FOR
PRIVATELY OWNED DRINKING WATER WELLS
BACTERIA TESTING – Testing for coliform bacteria and e. coli is required for all new wells. The WUPHD cannot approve a new well without a non-positive bacteria test result. Sample bottles are available at all WUPHD offices or from the MDCH laboratory located on the Michigan Tech campus. The MDCH lab testing fee is $16.
CHEMISTRY TESTING - Chemistry testing is optional but recommended. A water sample will be tested for Iron, Sodium, Nitrates, Nitrites, Hardness, Sulfate, Chloride, and Fluoride. A chemistry test sample bottle can be obtained from the WUPHD or from the MDCH laboratory located on the Michigan Tech campus. The MDCH lab testing fee is $18. Advisory – Deep wells drilled in the Freda Sandstone formation can have poor water quality with objectionable levels of chlorides, hardness, iron and sodium. These high concentrations impart a salty or bitter taste to the water and cause scaling, blackening, and pitting of plumbing fixtures. High sodium levels may be a health concern to a person on a sodium-restricted diet. Consult with health department staff regarding specific well construction techniques and water treatment methods which can be used improve the water quality when drilling a well in the Freda Sandstone formation.
FLUORIDE ADVISORY– Certain areas in Houghton and Keweenaw Counties, especially along the Lake Superior shoreline between McLain State Park and Five Mile Point, have produced high fluoride levels in private wells. It is strongly recommended that private wells in this area be tested for fluoride. Elevated levels of fluoride may cause dental fluorosis, a brown staining and/or pitting of the permanent teeth in young children. Dental fluorosis occurs when developing teeth (before they erupt from the gums) are exposed to elevated fluoride levels. Exposure to drinking water levels above 4.0 mg/L for many years may also cause crippling skeletal fluorosis, a serious bone disorder. Some wells tested in Stanton, Hancock, Allouez, Portage, and Eagle Harbor Townships have had fluoride levels between 4.0 and 10.3 mg/L. Chemistry testing will provide a fluoride level as well as useful information about other water quality parameters such as iron, sodium, nitrates, nitrites, hardness, sulfate, and chloride levels. A chemistry test sample bottle can be obtained from the WUPHD or from the MDCH laboratory located on the Michigan Tech campus. The MDCH lab testing fee is $18.
URANIUM ADVISORY– Scattered drinking water sources in the Western Upper Peninsula have been found to contain uranium in amounts that exceed the federal Maximum Contaminant Level. The source of the uranium may be the shale deposits that run inconsistently through the Jacobsville Sandstone formation. Water supplies with radioactivity have been found in Baraga, Gogebic, Houghton, Keweenaw, and Ontonagon Counties. The health effects of uranium exposure in the amounts that we have seen are mainly limited to kidney damage with long-time use. There is also a very small possibility of an increased risk of cancer over a lifetime of exposure. We caution people with wells constructed in the Jacobsville Sandstone formation that the possibility of uranium contamination exists and advise that their water be tested for uranium. The MDCH lab in Lansing is certified to test for uranium. Sample bottles can be obtained from the MDCH lab located on the Michigan Tech campus. The MDCH lab testing fee is $18.
NOTE - Well drilling contractors are required to construct wells according to Michigan’s Well Construction Code and use techniques which ensure the well water is free of coliform bacteria; however, there is no guarantee regarding water quality and quantity. Groundwater wells constructed in the Western Upper Peninsula can produce very low water volumes, and have objectionable levels of naturally occurring chlorides, hardness, iron, fluorides, etc. Property owners are strongly encouraged to discuss potential water quality and quantity problems with their well driller and the health department prior to constructing a well.
Map of Uranium and Floride Area
Recommended Well Construction for Water Wells Constructed in the Freda Formation
Numerous new water wells that have been constructed deep into the Freda Sandstone Formation (greater than 50 feet into the sandstone) have resulted in non-potable, poor water quality consisting of high concentrations of chlorides, hardness, and sodium. These high concentrations impart a salty taste to the water and cause scaling, blackening, or pitting of plumbing fixtures. A high amount of sodium in drinking water is a concern to a person on a sodium-restricted diet. The deeper the wells have been drilled into the Freda Formation, the higher the concentrations occur.
Chloride and hardness levels over 250 mg/L and sodium levels over 120 mg/L are considered to be objectionable and water treatment would be recommended. Elevated chloride levels can be reduced with residential water treatment units such as distillation, ion exchange, or reverse osmosis. Elevated sodium levels can also be reduced with either reverse osmosis or distillation. No economical residential treatment is available for high concentrations levels over 2,200 mg/L Total Dissolved Solids. With extremely high concentrations, well abandonment would be recommended.
Potable water (low or no concentrations of chlorides, hardness, and sodium) has been found either just above the Freda Formation at the overburden/sandstone interface, shallow in the Freda Formation approximately 10-15 feet into the formation, or by hydraulic fracturing the upper formation.
The following recommendations should be considered when constructing a well in the Freda Formation:
· Attempt to obtain water in the overburden above the sandstone (if greater than 25 feet of overburden) or immediately into the sandstone (minimum of 25 feet of casing applies).
· If water is not available above the sandstone, do not case off the upper 10 feet of the sandstone if possible. Limit the casing depth to terminate immediately into the formation. If the well needs to be hydraulically fractured, the upper formation is the fracture zone where potable water may be obtained.
· Terminate the well no deeper than approximately 50 feet into the Freda Sandstone. Depths greater than approximately 50 feet into the Freda Sandstone have been known to produce salt water.
· A well that needs to be hydraulically fractured at shallow depths to obtain potable water must be constructed with neat cement grout (not dry granular bentonite).
· If hydraulic fracturing of the well is a possibility, location of the well is important in order to meet the following isolation distances: 200 feet from neighboring wells and bedrock outcrops, 100 feet from surface water, and 800 feet from known sources of ground water contamination.
Note: A hydraulic fracturing permit ($103) is required prior to hydraulic fracturing (application of greater than 250 PSI of pressure) of a well. If less than 250 PSI of pressure is applied, it should be noted on the remarks section of the well record.