Kwik Trip and Hy-Vee donated water to the village of Williams Bay after nitrites were found in the village's water supply. On Friday, Aug. 29, 2025, four semis of water were delivered. Of that, water from 22 palates were distributed to residents.
Williams Bay Village President Adam Jaramillo, Village Police Officer Mark Erickson and Lions Club member Mike Broll load water into a truck while volunteering Friday, Aug. 29, 2025.
WILLIAMS BAY — The village of Williams Bay has alerted residents that its well water is contaminated with nitrites and cautioned them not to drink, brush their teeth or cook with it.
Kwik Trip and Hy-Vee donated water to the village of Williams Bay after nitrites were found in the village's water supply. On Friday, Aug. 29, 2025, four semis of water were delivered. Of that, water from 22 palates were distributed to residents.
Courtesy Williams Bay Police Department
The advisory will be in place until nitrite levels throughout the village’s water system are “acceptable and below the maximum threshold,” Village President Adam Jaramillo said in a letter to residents, shared with The 69.
A nitrite is a naturally occurring molecule that can enter groundwater from animal and human waste, or fertilizers. It is used in food preservation, some medications and the production of munitions and explosives.
Jaramillo told The 69 on Friday that four of five locations in the village tested higher than the one milligram per liter threshold set by the Wisconsin Department of Natural Resources. Those readings were 2.3, 2.6. 2.6, 2.4 and 0.83. on Wednesday.
Williams Bay Village President Adam Jaramillo, Village Police Officer Mark Erickson and Lions Club member Mike Broll load water into a truck while volunteering Friday, Aug. 29, 2025.
RYAN SPOEHR/RYAN.SPOEHR-SW.COM
He said that a test on July 30 came back as all under the threshold.
“There was sort of a failure of systems,” Jaramillo said, adding that there needs to be more regulation of ammonia in Wisconsin sewer systems. “We didn’t even know it happened until we were told.”
Nitrification is a process in which compounds like ammonia are oxidized to molecules like nitrite and nitrate, both of which were molecules that were tested for in the water. Nitrification is optimum between 77 degrees and 86 degrees, according to the Environmental Protection Agency.
So, after July 31, the chance for nitrites in the water was high because of higher temperatures.
To address the issue, the village will temporarily increase chlorine levels at its water plant and flush its distribution system.
Water plant upgrades
According to Jaramillo’s letter, the Wisconsin Department of Natural Resources informed the village that its water system’s ammonia levels were trending upward in 2021, which eventually could lead to elevated nitrite levels. The village then planned upgrades to its water plant, which were approved by the DNR, that included automatically adding chlorine to the water. The village borrowed the money for the project and it is under construction. It is set to be done in November.
“We’re going to be more proactive to make sure it doesn’t happen again,” Jaromillo said.
Police Lt. William Kostock wrote a letter to the community as well, in which he urged residents not to treat the water themselves. He wrote that tap water may be used for showering and bathing, handwashing, dishwashing and toilet flushing. He also indicated that the village is working with the DNR to flush hydrants, collect water samples and send samples to labs for analysis.
Bottled water distribution
At an emergency meeting Wednesday, the village board authorized up to $100,000 to provide emergency supplies to address the high nitrite levels and to provide bottled drinking water to all residents while the order in effect.
Each day through Monday, bottled water will be handed out for free at Williams Bay Middle/High School, 500 W. Geneva St., from 3-7 p.m. On Tuesday, hours for water distribution are 4-7 p.m. After that, distribution is to be determined. Residents are to enter from Theatre Road and exit onto State Highway 67. Residents should be prepared to give their name and address.
Kwik Trip and Hy-Vee have donated palettes of water. Village residents, the Williams Bay Volunteer Fire Department and the Fontana Emergency Medical Services have volunteered to hand out the water. On Thursday, 32 palettes of water were delivered. Of those, 24 were handed out. That was equivalent to about 8,000 gallons of water.
Mercyhealth hospital
In a statement to The 69, Mercyhealth Vice President Kara Sankey confirmed that Mercyhealth Hospital and Medical Center–Walworth is within the affected area. The hospital is about a mile outside of the village at the intersection of state highways 50 and 67.
“Mercyhealth is working closely with the Village of Williams Bay and the Walworth County Health Department to carry out all of the necessary protocols to keep our patients, their families and our employees safe during this time,” Sankey said. “We have protocols in place for situations like these so that patient safety is maintained.”
Tuesday village board meeting
In the letter to village residents Wednesday, Jaramillo welcomed them to attend the village board meeting Tuesday, Sept. 2, at the Williams Bay School, 250 Theatre Road starting at 6:30 p.m. More information on the situation will be shared at the meeting, Jaramillo said.
