Frequently Asked Questions

RPU is planning ahead to make sure Rochester continues to have safe, reliable drinking water for generations to come.

One challenge is that Rochester relies on the Jordan Aquifer as its primary water source. To ensure groundwater resources remain accessible for the future, Minnesota sets limits on how much communities can withdraw from aquifers. The Jordan Aquifer has served Rochester well for more than 130 years, but Rochester is expected to reach its current withdrawal limit within the next decade. That's why RPU is evaluating future water sources and planning for the community's long-term water needs.

At the same time, drinking water standards continue to evolve. To protect public health, RPU must make sure our water meets over 90 federal primary drinking water standards required by the EPA and Minnesota Department of Health. Meeting those standards in the future will require upgrades to how we treat and move water throughout the community. 

RPU is in the beginning stages of identifying and securing a new water source and modernizing our water system. By doing this now, RPU can continue providing safe, reliable water while planning responsibly for future growth. Taking action today also allows us to spread the costs for investment over a longer period of time.

Rochester Public Utilities (RPU) serves more than 42,000 water customers and more than 61,000 electric customers. It is the largest municipally owned electric and water utility in Minnesota.

RPU is responsible for the planning, investment and maintenance of Rochester’s water system to ensure residents have safe and reliable drinking water today and in the future. This includes:

1. Protecting water quality and meeting all state and federal regulations
2. Planning for Rochester’s growth and future water needs
3. Securing reliable and sustainable water supply resources
4. Managing water resources responsibly for future generations
5. Using scientific forecasts and groundwater modeling to help guide long-term water supply decisions

Yes. Rochester’s drinking water is safe today and meets all primary drinking water standards established by the U.S. Environmental Protection Agency (EPA) to protect public health.

However, Rochester’s source water contains high levels of naturally occurring minerals, including iron and manganese, as well as elevated water hardness. While these do not pose a public health risk at current levels, they can cause rusty water and stain plumbing fixtures and laundry. Because Rochester does not currently have a way to filter and treat our water, customer complaints regarding these aesthetic water-quality issues are around twice the national average. As drinking water standards continue to evolve, RPU will need to make additional investments in the City’s water system to continue providing safe, reliable and high-quality water.

An aquifer is an underground layer of permeable rock, gravel, sand or silt that stores water. Groundwater from aquifers provides a water source for many communities throughout Minnesota. The Jordan Aquifer, Rochester’s primary water source, is located about 400 feet below ground. RPU uses wells to pump the water up from the aquifer and distribute it to customers.

While aquifers are a reliable source of fresh water, they can be affected by over-pumping and pollution. When too much water is drawn from an aquifer, it can impact surrounding streams, wetlands and other natural resources. Similarly, pollutants can seep into the aquifer over time, making it harder to provide safe drinking water without treatment. That is why the state sets limits on how much can be pumped from an aquifer, and the federal government sets water-quality standards that utilities must meet.

Rochester is approaching our annual volume limit (appropriation) that RPU can draw from the Jordan Aquifer, as determined by the State of Minnesota. Before the State will authorize an increase in pumping from the Jordan Aquifer, RPU must conduct the extensive studies to ensure that the aquifer is not reaching its yield limit and that additional pumping would be sustainable. As Rochester grows and water demand increases, RPU must plan now to secure additional water supplies and make long-term investments in the community’s water system.

Though the Jordan Aquifer still has water, the state sets volume limits because pumping beyond a certain point can harm the aquifer itself and potentially impact surface waters. Streams, wetlands and other natural resources rely on groundwater, and pumping too much water can affect those ecosystems over time.

Planning ahead gives us time to study the options carefully, engage the community and make thoughtful decisions about Rochester’s future water supply.

Rochester’s water system was built over time by adding wells as the City grew. This “grow as you go" approach successfully met the community’s needs for many years, but it was not designed for the challenges we face today. The City now operates roughly 30 wells across our community and doesn’t have a centralized system that allows RPU to collect, treat and redistribute water.

Because our system wasn’t designed for centralized treatment, future upgrades are more complex and costly and will likely require new infrastructure. In practical terms, that could mean enhancing existing piping and wells, building treatment facilities and updating the overall system to move treated water where it is needed.

RPU has started planning now, so we can phase investments over time and spread out the cost of upgrades over a longer period.

For many decades, the Jordan Aquifer has provided safe, clean water for Rochester. We have not needed to treat our water in the past to meet primary drinking water standards established by the U.S. Environmental Protection Agency to protect public health. Because of this, the system was able to be built as we grew, handling immediate needs as they arose.

Rochester’s source water contains high levels of naturally occurring minerals, including iron and manganese, as well as elevated hardness, which can exceed federal secondary water quality standards for aesthetics. While these do not pose a public health risk at current levels, they cause rusty water and stain plumbing fixtures and laundry leading to elevated levels of customer complaints. 

As the years have gone by, water quality standards have become stricter, and new contaminants are being monitored more closely.

Without a water treatment facility, the community does not have a protective barrier to remove contaminants that may arise in the future or meet changes in federal primary drinking water standards.

To continue meeting future standards and providing safe, reliable drinking water, Rochester will likely need to add water treatment facilities in the years ahead.

No. Even if Rochester stopped growing tomorrow, meeting water safety and quality standards over the years ahead would require major investments in our existing water system.

Drinking water standards continue to evolve, and Rochester is approaching the state-set limit for the amount of water RPU can be sustainably drawn from the Jordan Aquifer. Growth has increased water demand, but it did not create the underlying challenge. We would still need to plan for new water sources, water treatment and system upgrades regardless of growth.

Additionally, RPU is currently exceeding federal secondary standards for Iron and Manganese. While not a public health issue at current levels, these secondary standards are an indicator for when a utility should consider implementing improved water treatment facility improvements.

Without groundwater modeling studies, RPU can’t build more wells to support Rochester’s future growth and water needs. Without new treatment facilities, water quality could decline and create risks for public health.

If we get to the point where our system fails to meet federal safe drinking water standards, the Environmental Protection Agency (EPA) and state health agencies can require corrective actions, issue public notices and enforce compliance orders.

In short, doing nothing is not an option. Investments are needed to modernize our water system to maintain safe and reliable service. Delaying them would not eliminate the need for improvements. Instead, it would likely increase costs and make it harder to plan and spread investments over time.

Water for Tomorrow is Rochester Public Utilities’ (RPU) long-term investment plan to modernize the City’s water system to ensure Rochester has reliable, safe and accessible water for future generations. By planning now, RPU can phase investments over a longer period of time, reducing the impact on residents and avoiding costly decisions later.

The water system master planning process will make sure Rochester has a water system that meets regulatory standards, protects natural resources and provides enough water to meet the community’s long-term needs. This includes planning for new water sources and a modern distribution system to keep water safe, reliable and secure for decades to come.

The goal is simple: Provide reliable, safe water for the next generation and beyond.

We’re conducting a groundwater modeling study to determine how much water can be safely drawn from the Jordan Aquifer and whether additional pumping can occur without harming the environment. This work will help us better protect the water source we depend on while protecting natural resources.

At the same time, the study will identify potential alternative water sources and their impacts. By planning ahead, we can keep meeting our community’s water needs without pushing the aquifer beyond what it can sustainably provide.

Providing high-quality water while protecting our local environment goes well beyond Rochester. Meeting stricter water quality standards and protecting shared resources, including our rivers, streams and wetlands, is a regional challenge.

That's why RPU has been planning alongside neighboring communities as we identify and evaluate future water sources and treatment options.

We haven't ruled that out. Regional collaboration has been part of this effort from the start, but it's too early to know whether a shared treatment system is the best solution. We want to complete our studies before deciding which option best meets our community’s long-term water needs.

This is a core reason why we are doing in-depth studies right now. We need to understand how each potential option could affect rivers, streams, ponds, aquifers and wetlands. These studies are a critical part of the planning process and will help inform our decision.

Once we have the data, we'll be able to choose a path based on evidence rather than assumptions.

Major decisions will occur in phases, with more information becoming available after the groundwater modeling study results are released in late November 2026.

We don't know the final timeline yet because it will depend on the study results and the options that come out of the process. Once the results are available, we'll have a clearer picture of what comes next.

What we do know is that major investments are not expected to happen all at once. RPU plans to take a phased approach that spreads projects and costs over many years. This allows time to complete studies, develop recommendations, secure approvals, pursue state and federal funding opportunities and carefully plan for construction and implementation.

Rochester cannot construct new water supply wells in the Jordan Aquifer unless RPU can show that other water sources, such as different aquifers or surface water, are not workable options for meeting the community's needs.

Future growth requires Rochester to demonstrate that additional groundwater withdrawals can occur while remaining within the aquifer's sustainable capacity and meeting state requirements.

Groundwater modeling uses advanced computer programs to show how water moves underground and through nearby streams. It helps determine:

• How water flow rates in streams could potentially be influenced by groundwater pumping and withdrawals
• How much groundwater can be used without lowering aquifer levels too much
• Whether pumping could affect sensitive/protected wetlands known as calcareous fens

RPU’s groundwater modeling study covers a large area — more than 1,500 square miles.

We are evaluating both groundwater and surface water options.

The groundwater options include Wonewoc/Tunnel City Aquifer, Mt. Simon Aquifer and additional production from the Jordan Aquifer, provided all environmental standards can be met.

The surface water options include Zumbro Lake, where South and Middle Forks (streams) of the Zumbro River meet, South Fork Zumbro River near Silver Lake and the Mississippi River.

Groundwater and surface water sources are being evaluated based on a 2024 directive from the Minnesota Department of Natural Resources and applicable state regulations. These standards help determine whether a water source can provide a reliable supply while meeting regulatory requirements. Key evaluation criteria include:

1. Minnesota's groundwater appropriations sustainability standard for safe yield (Minn. Stat. § 103G.287)
2. Minnesota’s groundwater appropriations sustainability standard for potential impacts to stream base flow (Minn. Stat. § 103G.287)
3. Minnesota’s statutory protections for calcareous fens (Minn. Stat. § 103G.223)

Several groups play a role in shaping Rochester's long-term water future. Rochester Public Utilities (RPU) is leading the planning process and working with technical experts to assess future water supply options, water quality requirements and infrastructure needs.

The Minnesota Department of Natural Resources (DNR) is also an important part of the process because it regulates water use and helps ensure proposed solutions meet state requirements.

The RPU Board and Rochester City Council will review the study findings and help guide future investment and implementation decisions.

A team of representatives from municipal water utilities within Olmsted County are participating in the planning process and reviewing results.

These studies are designed to identify which options are technically and financially possible, helping decision-makers evaluate the most practical paths forward.

The groundwater modeling studies are expected to be completed in late November 2026. These studies will decide whether Rochester's current groundwater supply can meet future needs and find workable alternatives if more water sources are needed.

After the results are available, RPU will use the findings to assess long-term water supply, treatment and infrastructure needs and develop recommendations for future investment. Community members will be able to learn more as information is shared through public meetings, project updates and other communication efforts.

Residents and businesses can stay informed by following project updates, reviewing publicly available materials and participating in public meetings and discussions as information becomes available.

Rochester Public Utilities is committed to sharing updates throughout the planning process and providing information about future water needs, potential investments and any recommendations that emerge from the studies.

Anyone interested in the water system master planning process and groundwater study can send questions or comments directly to Rochester Public Utilities at waterfortomorrow@rpu.org.

Feedback from residents, businesses and other stakeholders can help decisionmakers understand community priorities and concerns as plans move forward. While technical studies and state requirements will help find workable options, public engagement helps ensure the process stays transparent and the community is informed.

It's too early to give a confident estimate because the path forward will depend on what the research shows.

If Rochester needs a new water source, RPU will need to build a system to safely draw, treat and distribute water throughout the community. These major capital investments could cost tens of millions of dollars or more, which is one of the reasons planning is happening now. Early planning provides time to look into state and federal funding opportunities and spread infrastructure projects over a longer period.

RPU will share more detailed cost estimates with the Rochester Public Utilities Board, City Council and the community as the studies progress.

The plan is to phase in the investments over many years rather than all at once. This does two things: it spreads cost over time, and it gives RPU opportunities to pursue state and federal funding when it's available.

Our goal is to keep the impact on customers as low as possible. Right now, RPU’s job is to develop a plan and be transparent with the Rochester Public Utilities Board, City Council and the public about the options, costs and recommendations that come out of the process.