Residents in Monticello received a cross-connection water survey in the mail this past spring, as questions continue to circulate in the community about the safety and quality of the town’s drinking water. 

Reports of discolored tap water have appeared on social media, with some residents describing it as brown and rusty. 

The mailing, dated March 19, asked residents to complete a cross-connection control survey required by the Illinois Environmental Protection Agency (EPA) and the Illinois Department of Public Health. The form asks homeowners to identify plumbing features such as irrigation systems, private wells, water softeners and other fixtures that could allow drinking water to come into contact with non-potable sources — a situation known as a cross-connection. 

Kevin Rose, Monticello’s water plant operator, said the survey is part of a routine process required by the state.

“This is actually something that we’re supposed to do every three years just to get an idea of what is a potential source of contamination in our distribution system,” Rose said. 

He said the city reviews completed surveys to determine whether additional inspection is needed.

“We review all of those questionnaires, the surveys, and kind of determine if there are any areas that maybe need to have someone who is licensed go to install back flow preventers, [reduced pressure zone devices], things like that just to prevent potential contamination,” he said.

Rose said there are currently no known contamination issues in the system as of June 18. 

Maura Metcalf, Monticello’s finance and human resources director, said the city historically focused its cross-connection control efforts on commercial and industrial customers that were required to submit backflow prevention device testing reports. Metcalf said Rose, who began as water plant operator in June 2025, later determined the city needed to conduct a more comprehensive review of residential properties, prompting the cross-connection survey. 

The city does not have records of any previous residential cross-connection surveys, Metcalf said. She said any records that may have existed from earlier surveys would be more than 10 years old and were destroyed in accordance with the city’s and state’s records retention policies. 

However, the Illinois EPA identified six potential sources of contamination within or near the city’s well protection area in 2011 through its Source Water Assessment and Protection program. In the city’s 2024 consumer confidence report, the same sources of contamination were listed.  

According to the agency’s mapping system, the sources include three underground petroleum storage sites, an above-ground storage site, a furniture refinishing facility and a municipal building. 

Program data identifies two sites associated with Viobin, a Monticello-based wheat germ processing company. One site was previously described in the 2011 source water assessment as an above-ground storage facility and the other site as an Illinois Power Company machine shop. The building that housed the former machine shop is now owned by Viobin. 

Several of the facilities identified in the assessment are no longer operating. Kerr-McGee, identified as an underground storage tank site, and Leiper Furniture, a furniture refinishing operation, have closed. Super Pantry has been rebranded as Circle K, and Viobin continues to operate in Monticello. 

The 2011 source water assessment also notes other potential contamination sources exist in the wellhead protection area, derived from Illinois EPA’s Leaking Underground Storage Tank database. The database identifies 15 sites in Monticello where underground storage tanks have leaked in the past, though those sites are not among the six facilities highlighted on the agency’s current mapping system. 

Monticello’s drinking water comes from four community groundwater wells located near the center of town on the south side of Center Street. The wells draw from a sand-and-gravel aquifer and together supply an average of about 550,000 gallons of water per day to more than 2,200 service connections. 

However, the agency concluded the wells were not considered susceptible to volatile organic compounds, synthetic organic compounds or inorganic contamination based on available monitoring and hydrogeologic data. 

Recent water quality reports show no violations

Water quality reports from 2020 through 2024 show no violations of state or federal drinking water standards, with testing consistently finding contaminant levels below regulatory limits.

Levels of lead and copper remained below federal action thresholds each year, while nitrate levels stayed well under regulatory limits. Disinfection byproducts, including trihalomethanes and haloacetic acids, were also consistently within allowable ranges.

According to the Illinois EPA, Monticello has not recorded any violations of drinking water standards since 1985. The agency noted that while the system has remained in compliance, certain contaminants have required increased monitoring in recent years. 

However, in 2023, Monticello was placed on increased arsenic monitoring by the agency, shifting from annual to quarterly testing after levels reached 10 micrograms per liter, the federal maximum contaminant level. Results have remained below that threshold since, according to the agency.

The agency also reported increased monitoring for lead and copper beginning in 2023, triggered by copper levels reaching the action level of 1.3 milligrams per liter at the 90th percentile of sampled homes. Since then, copper levels have declined, and in 2026 the system was returned to less frequent, triennial monitoring after results remained below 1 milligram per liter.

In response to questions about lead levels, the Illinois EPA said the 90th percentile of “20 samples for lead has been non-detectable since 2023” and has never exceeded the federal action level of 15 micrograms per liter. The highest recorded level was 5 micrograms per liter in 2017.

But a national analysis by the nonprofit advocacy organization Environmental Working Group found several contaminants in Monticello’s water system at levels exceeding the group’s own health-based guidelines, despite remaining below federal legal limits.

The organization’s national Tap Water Database, which draws on utility testing data reported to regulators, flagged disinfection byproducts, including total trihalomethanes and haloacetic acids, along with low levels of nitrate, PFOS and PFOA. 

Kim Biggs, public information officer for the Illinois EPA, said in an email that some contaminants found in drinking water are naturally occurring.

“While there are several potential causes of discoloration, ‘rusty’ water often indicates the presence of iron,” Biggs said. “The two most recent test results for iron in the finished water leaving the plant were 12 and 63 micrograms per liter, which is under the state limit of 1,000.”

Iron is found naturally in the groundwater and removed by aeration and filtration at the water treatment plant, she said. 

“Iron can enter the water in the distribution system through corrosion of cast iron watermains,” she said. “A phosphate is fed at the treatment plant for control of iron, copper, and lead corrosion.”

According to the U.S. Geological Survey, arsenic can also enter groundwater through the erosion of natural deposits and is commonly found at low levels in water systems across Illinois. Federal standards set the maximum contaminant level for arsenic at 10 parts per billion to reduce long-term health risks.

While exposure to high concentrations of arsenic over extended periods has been linked to increased risks of cancer and other health effects, the U.S. EPA notes that levels below the federal standard are considered compliant with public health protections.

A 2023 Source Water Protection Plan prepared for the city by the state environmental agency noted that groundwater protection efforts are intended to reduce contamination risks from surrounding land use and industrial or agricultural activity near municipal wells. The plan was prepared with assistance from the Illinois Rural Water Association, a nonprofit that provides training and technical assistance across the state. 

The U.S. Centers for Disease Control and Prevention notes that identifying environmental causes of disease typically requires long-term epidemiological studies that examine patterns across populations over time.

The U.S. Geological Survey says that in agricultural regions, including much of central Illinois, groundwater can be influenced by surrounding land use. Fertilizers, pesticides and other agricultural inputs can enter groundwater through runoff or leaching, making contaminants such as nitrate a focus of monitoring in rural water systems. 

Monticello’s reports show nitrate levels remained well below federal limits across all five years of testing.