Monday, December 14, 2015 - 10:30am

UPDATE - 6/16/2016: 
Madison Water Utility officials had hoped to take Well 27 on North Randall Ave. out of service in the spring or summer in order to study the geology of the well's bore hole, but a mechanical failure at another well in the area has made it necessary to continue to run Well 27 until the fall or perhaps longer. Madison Water Utility will operate Well 27 on a very limited basis throughout the summer, barring a supply issue or drought that could cause the utility to run the well for longer periods. We will continue to monitor radium levels at the well while it is in service.


Madison Water Utility hopes to pinpoint possible sources of radium found in the water at a well just off campus. Two samples taken this fall from Well 27 on North Randall Ave. had radium levels of 5.6 and 4.3 picocuries per liter (pCi/L). Levels from samples taken at the well over the summer ranged from 3.3 to 4.3 pCi/L. The federal Maximum Contaminant Level (MCL) for radium is 5 picocuries per liter.
While the results do not point to an immediate health concern, Madison Water Utility plans to further investigate the issue. Radium has always occurred naturally in rock that makes up Madison’s aquifer, and variations in test results are not uncommon. The maximum contaminant level (MCL) for radium is meant to ensure the safety of water over a lifetime of consumption, and results would have to be consistently above the MCL for at least a year in order for the water to be considered in violation of federal health standards.
Still, Madison Water Utility takes this issue very seriously and plans to study the geology of the well’s bore hole to determine which rock layers may be contributing radium to the water supply. MWU will attempt to seal those layers if necessary. In the coming weeks, operation of the well will likely be brought down to about 12 hours a week until it is taken out of service for the study, which could happen as early as this spring.
The utility’s water quality team initially stepped up monitoring of the well after seeing an unexpected increase in radium levels last February. Those levels dropped in April, but went up again in May.


  • For Media Inquiries: Amy Barrilleaux, Public Information Officer, (608) 266-9129

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