With the recent situation of high levels of lead in the tap water in Flint, Michigan, customers have been inquiring about the presence of lead in Monona's water supply. Here is some information for our customers:
Monona’s water comes from three groundwater wells which pump from the Sandstone Aquifer. Well 1, constructed in 1960, is 305’ deep; Well 2, constructed in 1958, is 500’ deep; and Well 3, constructed in 1967, is 775’ deep. Before the water reaches your tap it is treated with a Sodium Hypochlorite solution for disinfection purposes and with Fluoride to assist with dental protection.
The Monona Water Utility routinely monitors our water for potential contaminants according to Federal and State law. Monona’s drinking water is safe and meets all Environmental Protection Agency (EPA) and Department of Natural Resources (DNR) standards, and the City of Monona has had no violations of EPA or DNR safe drinking water requirements. The City issues an annual water quality report which is posted on this site and available at City Hall for the public to review. The City's water quality reports show lead levels well below the EPA's action level of 15 parts per billion (ppb). In 2017, the City's lead level was 3.65 ppb. View the 2017 water quality report.
Where Does Lead in Water Come From?
In Monona, the mains that bring water from the wells to your home are constructed of ductile iron. However, lead still can be found in some metal water taps, interior water pipes, or pipes connecting a house to the main water pipe in the street. Lead found in tap water usually comes from the corrosion of older fixtures or from the solder that connects pipes. When water sits in leaded pipes for several hours, lead can leach into the water supply. When your water has been sitting for several hours, you can minimize the potential for lead exposure by flushing your tap for 30 seconds to 2 minutes before using water for drinking or cooking.
How Can I Tell If I Have Lead Pipes?
To determine whether your water lateral (the pipe which brings water from the main in the street to your house) is made of lead, locate the water service line coming into your home. It will usually be located in the basement with an inlet valve and water meter installed right after the line enters the building. Use a screwdriver to scrape a small area of the pipe. If the scraped area is shiny and silver and a magnet will not stick to it, then it is made of lead. If the scraped area remains a dull gray and a magnet sticks to it, then it's a galvanized steel pipe. If the scraped area is copper-colored and non-magnetic, then it's a copper pipe. If you've determined that you have a water lateral made of lead or other lead pipes in your home, visit http://www.cdc.gov/nceh/lead/tips/water.htm for more information on minimizing lead in your drinking water.