Carson City well source test shows manganese level above secondary drinking water standard
Submitted by Jeff Munson on Tue, 07/27/2021 - 1:50pm
Carson City Public Works would like to provide some information on recent water quality testing that has reported a level of manganese above the secondary drinking water standards.
EPA has established National Secondary Drinking Water Regulations (NSDWRs) that set non-mandatory water quality standards for 15 contaminants. EPA does not enforce these "secondary maximum contaminant levels" (SMCLs).
They are established as guidelines to assist public water systems in managing their drinking water for aesthetic considerations, such as taste, color, and odor. These contaminants are not considered to present a risk to human health at the SMCL.
Manganese may become noticeable in tap water at concentrations greater than 0.05 mg/L by imparting a color, odor, or taste to the water. However, health effects from manganese are not a concern until concentrations are approximately 10 times higher.
Carson City Public Works routinely monitors the City's wells for the presence of drinking water contaminants. One of the source wells (out of 30 wells) on the east side of Carson City recently exceeded a secondary drinking water standard for Manganese in one sample taken in March 2021. The NV State standard for manganese is 0.1 mg/L. The average over the first quarter (January, February, March of 2021) detected concentration was 0.4 mg/L.
On a monthly basis, Carson City Public Works will take samples to test for Manganese at this well source. The samples for every month, except March, have been meeting the standard. Although this is not an emergency, as our customers, you have a right to know what happened, what you should do, and what we did and are doing to correct this situation. A flyer will be sent out to all customers in the next utility billing to help explain the matter in more detail.
What should I do?
You do not need to use an alternative (e.g., bottled) water supply. Manganese is an aesthetic concern. However, if you have specific health concerns, consult your doctor.
What is being done?
We are continuing to monitor for manganese monthly at this site. The past three months since March 2021, the levels have been meeting standards. For more information, please contact Eddy Quaglieri, Water Utility Manager, with Carson City Public Works at (775) 283-7395.
Visit carson.org/notice for FAQs and additional resources and information about Manganese. Please share this information with all the other people who drink this water, especially those who may not have received this notice directly (for example, people in apartments, nursing homes, schools, and businesses).
