Grinnell water has levels of radium above drinking water standards

The City of Grinnell is in the process of building a new water treatment plant that will effectively reduce radium levels to below standards set by drinking water regulations. This project has been underway for four years, and the new treatment plant is planned to be operational in January 2027.

Radium is naturally present in the water drawn from the Jordan Aquifer, which supplies Grinnell's water. Recent water tests show that the Grinnell water system has radium levels higher than the standard set by drinking water regulations. Notifications received on March 17, 2026, for both 4th quarter 2025 and 1st quarter 2026 indicate that the system exceeds the standard, or maximum contaminant level (MCL), for radium, combined (226,228). The standard for radium, combined (226, 228) is 5 pCi/L.

• The yearly average for 4th quarter 2025 was 7.79 pCi/L
• The yearly average for 1st quarter 2026 was 8.13 pCi/L

While this is not an emergency, the City of Grinnell aims to inform the public about what this means, any necessary actions, and the steps being taken to address the issue.

Monitoring violation notice

The City also received a monitoring violation notice on March 17, 2026. Even though this was not an emergency, customers have a right to know what happened and what is being done to correct it. The Grinnell Water Department is required to regularly test drinking water for contaminants. These results help confirm whether water meets health standards. 

During the 3rd quarter of 2025, testing results for Combined Radium and Gross Alpha from Wells 6, 7, 8, and 9 conducted at the plant after treatment were not received. Because of this, we cannot confirm water quality for that specific time period. The sampling deadline was missed due to an issue in the laboratory. 

The City has since switched laboratory service providers and is implementing more stringent tracking and recordkeeping procedures to ensure this does not happen again. 

Treatment options

Certain types of home water softeners and reverse osmosis treatment units can be effective at removing radium from drinking water. Boiling water and carbon-based drinking water filters are not effective methods of removing radium.

What is being done?

Radium is naturally present in the water drawn from the Jordan Aquifer, which supplies Grinnell's water. The current water treatment plant does not have the capability to remove radium. To address this, the City of Grinnell is constructing a new water treatment plant that include technology to reduce radium levels. The plant is expected to be operational by January 2027. 

In the meantime, the water department is using the best available wells to help manage radium levels, though current treatment options cannot fully reduce them below the regulatory limit.

For more information

Contact: Keagan Richmond, Water Director, 702 Main St., 641-990-7521Drinking Water Requirements-Radionuclides Rule, U.S. EPARadium Testing Results in Public Water, Iowa Health & Human ServicesCity of Grinnell Water Improvements Overview3rd Quarter 2025 Monitoring Violation4th Quarter 2025 Radium Violation Notification1st Quarter 2026 Radium Violation Notification

Nanofiltration Water Treatment Plant: Glass and doors are now installed on the east-side office area. Roof insulation and membrane are complete. Interior masonry work is ongoing. The plant water main tie in is finished, with additional piping being laid to the west. The flush box for treatment waste is installed and the aerator has arrived on site. 

South Water Tower: Caldwell crews have demobilized until weather conditions improve. Van Maanen is working on installing fiber optic communications from the tower site to 1st Avenue. 

Jordan Well No. 10: Well development is ongoing and will continue in coordination with work on the water treatment plant.

Nanofiltration Water Treatment Plant: Roof decking has been installed, roof insulation has arrived, and work continues on roof penetrations. Overhead doors are being installed, and the building is being closed in so interior work can progress inside over the winter. Wendler plans to begin excavating for pipe installation in coming weeks, and plant equipment is beginning to arrive on site. 

South Water Tower: Work continues as weather allows. Much of the tank has been assembled at the base of the pedestal, with remaining sidewall sections and the roof still to be assembled before the tank is raised to its final height. Interior work within the tower pedestal will also continue as time and weather permit. 

Jordan Well No. 10: The well project remains in development.

Nanofiltration Water Treatment Plant: All exterior block walls are complete, brick is being installed on the outside, and interior block walls are under construction. All concrete floors are installed except for one small area, which will be finished shortly. Roof trusses and garage doors are being installed, and the crew expects the building to be enclosed before harsher winter weather arrives. The clear well (where treated water is stored before distribution) has passed all testing and is now complete. 

Water Tower: The crews responsible for constructing the steel tank is mobilizing, with a generator and other equipment on site. Tank assembly is set to begin on November 11 and will continue through the winter. The tank is scheduled to be raised to the top of the pedestal in February and will be painted as weather allows in the spring. 

Jordan Well No. 10: The test pump has been delayed yet again due to equipment issues. 

Nanofiltration Water Treatment Plant: The plant site is starting to look like a building as block is laid to form walls. WRH is completing footings, grading, and coordinating with plumbers to install drainage in preparation for pouring the floor in the coming weeks. Electricians are burying pipe to power the treatment units and pumps. The clear well (where treated water is stored before distribution) is nearly finished and being prepped for painting. 

Water Tower: The final concrete pour for the pedestal is scheduled for September 15, bringing the structure to 120 feet. Steel for the tank will arrive soon, with assembly beginning in November. In the meantime, electrical service, interior piping, and ladders will be installed. Once complete, the tower will stand 164 feet tall. 

Jordan Well No. 10: A test pump was conducted today, and results are pending. If successful, this will wrap up the current phase of the well saga. 

Nanofiltration Water Treatment Plant: WRH continues to pour footings and foundation walls and is installing underground piping as the building footprint nears completion. DN tanks is now on-site and preparing to begin construction of the 300,000-gallon clearwell (the enclosed tank that holds treated water before distribution to the public). 

Jordan Well No. 10: Well drilling, casing installation, and initial test pumping are complete. The pitless adaptor (the above-ground well connection) has been installed. The well is currently being inspected using a downhole camera to capture video of the interior and check for any flaws. Final finishing work and an additional test pump will be completed before closing out this phase. 

Raw Water Transmission Line: Installation of the raw water transmission main is complete. Initial grass seeding showed early promise but has not established as expected. Re-seeding is planned for late August or September where needed.

Water Tower: Construction of the water tower is progressing quickly. Caldwell Tank has poured four segments of the tower pedestal and anticipates pouring multiple segments each week moving forward. Expected completion of the water tower is fall 2026.

Recent water tests show Grinnell’s public water system has elevated levels of radium and gross alpha, both naturally occurring substances found in groundwater. While levels are above federal drinking water standards, this is not an emergency, the water remains safe to drink and use for daily activities.

Test results:

Radium (combined 226/228)

• Standard or maximum contaminant level (MCL): 5 picocuries per liter (pCi/L)
• Grinnell’s average: 6.4 pCi/L (based on testing results received June 30, 2025)

Gross Alpha (excluding radon and uranium)

• Standard (MCL): 15 pCi/L
• Grinnell’s 2024 quarterly results:
  1. Q1: 15.65 pCi/L
  2. Q2: 20.1 pCi/L
  3. Q3: 20.5 pCi/L
  4. Q4: 21.8 pCi/L

Is the water safe?

Yes. While above the federal limit, the detected levels do not pose an immediate health risk. Long-term exposure to higher levels may carry some risk. Those with health concerns should consult their doctor.

What are radium and gross alpha?

Radium is a naturally occurring radioactive metal found in rocks and soil.

Gross alpha measures radiation released as elements (such as radium) break down in the environment.

Because radium emits alpha particles as it breaks down, elevated levels of radium in the water contribute to higher gross alpha readings. The U.S. Environmental Protection Agency (EPA) sets limits on both to protect long-term health.

Treatment options

Certain types of home water softeners and reverse osmosis treatment units can be effective at removing radium from drinking water. Boiling water and carbon-based drinking water filters are not effective methods of removing radium. 

What is being done?

Grinnell’s current water treatment plant does not have the ability to remove radiological contaminants, but a new treatment plant is under construction with the technology to reduce them. The plant is expected to be operational by December 2026. In the meantime, the water department is using the best available wells to help manage contaminant levels, though current treatment options cannot fully lower them below the regulatory limit.

For more information

Contact: Keagan Richmond, Water Director, 702 Main Street, 641-990-7521Drinking Water Requirements-Radionuclides Rule, U.S. EPARadium Testing Results in Public Water, Iowa Health & Human ServicesCity of Grinnell Water Improvements OverviewGet updates by signing up for city alerts

Jordan Well No. 10: Drilling has reached the target depth, with the static water level measured at 525 feet below the surface. The drill has been removed and remaining equipment will be cleared from the site once testing is complete. During testing, water will be pumped into the storm sewer at 2nd Avenue and Broad Street. While the crew intends to contain the water from the testing, some water may reach the roadway.

Raw Water Transmission Line: Installation of the raw water transmission main is complete. Only minor site cleanup remains.

Water Tower: The foundation for the new water tower has been poured and construction of the pedestal will begin soon. Expected completion of the water tower is fall 2026.

Nanofiltration Water Treatment Plant: WRH has begun pouring footings and foundation walls and is receiving deliveries of materials. Construction of the clearwell (the enclosed tank that holds treated water before distribution to the public) will begin in the coming weeks. The overall project remains on schedule, with completion anticipated in summer 2027.

Jordan Well No. 10: Crews are currently installing the well casing extension. Once installed, it will be grouted and the final segment of drilling will begin.

Well Transmission Line: Installation of the raw water transmission main is nearly complete, with work approaching it's endpoint at Well #8. Completion is expected in about two weeks. A service interruption will be required to connect the new main on 1st Avenue east of East Street; affected residents will be notified in advance. 1st Avenue and West Court Drive are expected to reopen within the next couple of weeks. Concrete replacement is ongoing. Final grading and seeding should be completed by the end of May.

Water Tower: Site work is underway, and equipment has been moved in. A concrete test piling was installed and tested last week; if results are favorable, foundation work will start soon. One short service interruption will be needed to connect the tower to the water main, but no street closures are expected. City Council has approved paint colors for the water tower. Project completion is anticipated by fall 2026. 

New Nanofiltration Water Plant: Major excavation work is in progress, with foundation construction to follow. The project remains on schedule, with completion expected in summer 2027.

Grinnell water has levels of radium, combined (226, 228) above drinking water standards

Recent water tests show that the Grinnell water system has radium levels higher than the standard set by drinking water regulations. Testing results we received on April 17, 2025 show that the system exceeds the standard, or maximum contaminant level (MCL) for radium, combined (226, 228). The standard for radium, combined is 5 pCi/L. The yearly average level of Radium, Combined over the last year was 6.45 pCi/L. While this is not an emergency, the City of Grinnell aims to inform the public about what this means, any necessary actions, and the steps being taken to address the issue. 

Is the water safe?

Yes, Grinnell's water remains safe to drink, bathe in, and use for everyday activities. While the detected radium levels are slightly above the regulatory limit, they do not pose an immediate health risk. Radium must be ingested at much higher levels over a very long period of time to pose significant health risks to the average person. Individuals with specific health concerns should consult their doctor.

What is radium?

Radium is a naturally occurring radioactive metal that is found at very low levels in rocks and soil and may strongly attach to those materials. Everyone is exposed to small amounts of radium through air, water, and food. The EPA has set a notification requirement for a drinking water limit of 5 picocuries per liter (5pCi/L) for the combined levels of radium-226 and radium-228 to minimize potential health risks. 

Treatment options

Certain types of home water softeners and reverse osmosis treatment units can be effective at removing radium from drinking water. Boiling water and carbon-based drinking water filters are not effective methods of removing radium. 

What is being done?

Radium is naturally present in the water drawn from the Jordan Aquifer, which supplies Grinnell's water. The current water treatment plant does not have the capability to remove radium. To fix this, the City of Grinnell is building a new water treatment plant, which will have the necessary technology to reduce radium levels. The plant is expected to be operational by December 2026. In the meantime, the water department is using the best available wells to help manage radium levels, though current treatment options cannot fully lower them below the regulatory limit. 

For more information

Contact: Keagan Richmond, Water Director, 702 Main St., 641-990-7521Drinking Water Requirements-Radionuclides Rule, U.S. EPARadium Testing Results in Public Water, Iowa Health & Human ServicesCity of Grinnell Water Improvements Overview

Jordan Well 10: The well casing has been installed, and crews are preparing for the final phase of drilling.

Well Transmission Main: Construction on the well transmission main has resumed. Crews are currently working between State and High Streets. High Street will be closed at 1st Avenue starting Tuesday, with the closure expected to last about one week. East Street will also be closed at 1st Avenue in the near future; notice will be provided ahead of time. Additionally, starting Tuesday, March 25, water main work will begin at Highway 6 and High Street. The middle two lanes will be closed to allow space for construction, but the road will remain open to traffic in both directions.

New Nanofiltration Water Plant: WRH, the contractor selected to build the new water treatment plant, is on site doing preliminary work for the plant. Excavation and construction will begin soon. The plant is expected to be operational by winter 2026 and final project completion in summer 2027

New Water Tower: City staff are reviewing design options for the new water tower. Construction is tentatively scheduled to begin in spring 2025, with completion expected by fall 2026.

Spring Hydrant Flushing: The Water Department will conduct hydrant flushing the week of April 14. Crews will begin at the water plant and proceed south, then west, east, and back to the plant. During this process, residents may notice discolored water. While the water remains safe to drink, it can stain clothing. Residents are advised to avoid doing laundry during flushing activities.

Jordan Well 10: After a brief period of repair, drilling of the new well has resumed and is making excellent progress. Current well depth is just over 1,500 feet below the surface. Installation of the well casing will begin next week, then drilling will resume again and continue through April. 

Well transmission main: Construction of the well transmission main along 1st Avenue will resume on March 17 with an anticipated completion in June.

New nanofiltration water plant: WRH, the contractor selected to build the new water treatment plant, is on site doing preliminary work for the plant. Excavation will start on March 24th.The plant is expected to be operational by winter 2026 and final project completion in summer 2027.

New water tower: City staff are reviewing design options for the new tower. Construction is tentatively scheduled to begin in spring 2025, with completion anticipated in fall 2026.

Jordan Well 10: Drilling has resumed following a holiday break and necessary repairs. The well has reached a depth of approximately 880 feet, with drilling expected to be completed by April.

Raw Water Main: Installation of the raw water main continues east of the railroad tracks along 1st Avenue and is currently near State Street. Road closures will move as work progresses, and affected residents will receive advance notification.

New nanofiltration water plant: The water plant design is complete, and WRH, Inc. of Amana, Iowa, has been awarded the construction contract. Work is set to begin in April, with the plant expected to be operational by winter 2026 and final project completion in summer 2027.

New water tower: City staff are reviewing design options for the new tower. Construction is tentatively scheduled to begin in spring 2025, with completion anticipated in fall 2026.

Work on Jordan Well 10: Work on the new drinking water supply well has been paused due to mechanical issues, but will start back up next week. Contractors are on site working to prepare for the arrival of the new drill rig to finish the drilling of the well. 

Raw Water Main: Tie-ins to the existing well lines at Main Street and 2nd Avenue have been completed. 200 feet of pipe will be laid along the north side of 2nd Avenue to complete this phase of work at the treatment plant site. If weather continues to hold, work will resume along 1st Avenue east of Park Street. 

New nanofiltration water plant: Design for the water plant is complete and the contract for construction of the plant has been awarded to WRH, Inc. of Amana, Iowa. Construction of the plant can begin after the new well is complete. We are expecting the plant to be in operation in the fall of 2026, with a final completion date in the spring of 2027.

Garfield Avenue water main: Work on the replacement of the Garfield Avenue water main between Main and Broad Streets will begin next week. There will be water interruptions later in the week, and the Water Department notified some affected residences of disruptions in person.  

New water tower: Construction of the water tower is tentatively scheduled to begin in spring of 2025, with estimated completion in fall of 2026.

Work on Jordan Well 10: Work on the new drinking water supply well has been paused due to mechanical issues. The small drill rig that was brought in for the initial drilling segment and casing drilled a 36" wide hole over 200 feet below ground before a driveshaft problem stopped work. A larger rig to complete the drilling is scheduled to arrive in late October or early November and will take over where the small rig left off. We anticipate that the February completion date for the well is still accurate.

Replacement of well transmission lines: The project to replace the lines that carry water from the wells to the water treatment plant has begun. This project takes place along 1st Avenue from the East end of 1st Avenue to the treatment plant site at 2nd Avenue and Broad Street. A crew has started the process at the treatment plant and is working toward 1st Avenue. 1st Avenue between Main and Broad Streets and a portion of Broad Street are closed and will reopen the week of October 21st (see map below for street closures). Every effort will be made to limit disruptions to traffic, but some closures will be necessary. Driveways affected by this project are being repaired as quickly as possible. Final completion date is in November of 2025, but work is not expected to take that long.

New water tower: Construction of the water tower is tentatively scheduled to begin in spring of 2025, with estimated completion in fall of 2026.

New nanofiltration water plant: Design is nearly complete. We are accepting bids for construction on October 17th. Construction of the plant can begin after the new well is complete. We are expecting the plant to be in operation in the fall of 2026, with a final completion date in the spring of 2027.

Garfield Avenue water main: Garfield Ave will be getting a new water main between Main and Broad Streets. The contractor hired had a vehicle accident involving multiple employees. They are all doing well, but will be delayed while they heal up. Once construction starts, residents who may be affected by shutdowns while the new main gets tied in will be notified before any interruptions occur. 

Since 2022, city staff and McClure Engineering have been working on multiple water system improvement projects. These projects will improve the quality of our water, ensure adequate water supply into the future, and allow for reliable water treatment and distribution processes. We are beginning to see the results of our design work and patience. 

Work on Jordan Well 10—a new drinking water supply well located on the future treatment plant site—started at the beginning of August. Cahoy Pump Service worked to drill a pilot hole to the depth of 215 feet below ground level. They are now reaming the pilot hole to a diameter of 36 inches, which has reached a depth of 115 feet below ground level. When the reaming is complete, Cahoy will install the first segments of casing pipe. The pipe sections will be welded together, lowered into the hole, and grouted in place to stabilize the hole for the next phase of drilling. Drilling was paused over the last week so that Cahoy could perform maintenance on the drill rig, but they should be back up and running in the next few days.

The project to replace well transmission lines—the lines that carry water from the wells to the water treatment plant—will start in September or October. This project takes place along 1st Avenue from the East end of 1st Avenue to the treatment plant site at 2nd Avenue and Broad Street. Multiple crews will likely be working on this at the same time for a more efficient install. Meetings with residents will be held so that plans can be communicated periodically. Every effort will be made to limit disruptions to traffic. This work is estimated to be complete in November of 2025.

Plans for the new one-million-gallon water tower that will be located on East Street just south of Ogan Avenue are complete. Caldwell Tanks Inc. out of Louisville, KY was the low bidder on the construction of the water tower, tentatively scheduled to begin in spring 2025, with estimated completion by May of 2026.

Garfield Avenue between Main and Broad Streets will be getting a new water main in the near future. Busy Bee Construction, of Lewsitown, MO was selected for this project. This project will include shutdowns to tie in the new main, but the entire project is anticipated to move along quickly once started. A start date has not been set yet. Affected residents will be notified before any water interruptions occur. 

Design of Grinnell’s new nanofiltration water plant is nearly complete. We are anticipating a bid date in mid-October. Construction of the plant can start after the new well is completed. We are expecting a completion date in spring of 2027. 

The City of Grinnell is putting together an inventory of water service lines in the city to determine the pipes' composition. If you're a resident of Grinnell, please complete the water service line survey at www.grinnelliowa.gov/waterline, or pick up a paper copy at City Hall or Drake Community Library. 

Grinnell water has levels of radium, combined (226, 228) above drinking water standards

Recent water tests show that the Grinnell water system has radium levels higher than the standard set by drinking water regulations. Testing results we received on January 28, 2025 show that the system exceeds the standard, or maximum contaminant level (MCL) for radium, combined (226, 228). The standard for radium, combined is 5 pCi/L. The yearly average level of Radium, Combined over the last three quarters of 2024 was 8.36 pCi/L, 7.94 pCi/L, and 7.325 pCi/L. While this is not an emergency, the City of Grinnell aims to inform the public about what this means, any necessary actions, and the steps being taken to address the issue. 

Is the water safe?

Yes, Grinnell's water remains safe to drink, bathe in, and use for everyday activities. While the detected radium levels are slightly above the regulatory limit, they do not pose an immediate health risk. Radium must be ingested at much higher levels over a very long period of time to pose significant health risks to the average person. Individuals with specific health concerns should consult their doctor.

What is radium?

Radium is a naturally occurring radioactive metal that is found at very low levels in rocks and soil and may strongly attach to those materials. Everyone is exposed to small amounts of radium through air, water, and food. The EPA has set a drinking water limit of 5 picocuries per liter (5pCi/L) for the combined levels of radium-226 and radium-228 to minimize potential health risks. 

Treatment options

Certain types of home water softeners and reverse osmosis treatment units can be effective at removing radium from drinking water. Boiling water and carbon-based drinking water filters are not effective methods of removing radium. 

What is being done?

Radium is naturally present in the water drawn from the Jordan Aquifer, which supplies Grinnell's water. The current water treatment plant does not have the capability to remove radium. To fix this, the City of Grinnell is building a new water treatment plant, which will have the necessary technology to reduce radium levels. The plant is expected to be operational by December 2026. In the meantime, the water department is using the best available wells to help manage radium levels, though current treatment options cannot fully lower them below the regulatory limit. 

For more information

Contact: Keagan Richmond, Water Director, 702 Main St., 641-990-7521Drinking Water Requirements-Radionuclides Rule, U.S. EPARadium Testing Results in Public Water, Iowa Health & Human ServicesCity of Grinnell Water Improvements Overview