Maintaining water and wastewater infrastructure is often a time-consuming and costly operation, requiring a diverse team with maintenance and operational skill sets to be successful. However, all water and wastewater infrastructure will eventually need renovations or rebuilds to remain useful. Retrofitting involves updating facilities in existing locations, providing a myriad of benefits by applying a strategic approach to the challenges of aging infrastructure.

Retrofitting is typically implemented as a cost-effective solution for updating water and wastewater facilities so that they comply with new state regulations. According to the Environmental Protection Agency, much of the original water and wastewater infrastructure was built in the United States 50 to 100 years ago. Additionally, the United States experiences about 240,000 water main breaks every year, impacting communities and treatment infrastructure. As municipalities look for a logical solution to their aging infrastructure challenges, they often look to a retrofit approach.

Top Reasons to Retrofit

The decision to retrofit, rather than rebuild, infrastructure is often dependent on budget constraints and facility size. Retrofitting also provides a variety of additional benefits:

  • Energy efficiency: Not only can retrofitting an existing facility save both time and money, but the new operations scheme can save energy as well. According to the Office of Energy Efficiency and Renewable Energy, wastewater facility retrofits can yield up to 50% in energy savings and 30% on average, as many of the original treatment processes are rehabilitated as part of the project approach.
  • Improved public perception: Few want facilities built near where they live, work and play. Retrofits allow for the strategic use of public funds to update existing facilities and simultaneously avoid the “not-in-my-backyard” opposition.
  • Operational and regulatory consistency: Operations can be easier to manage with a retrofitting project compared to the process of building a new facility. By collaborating with existing staff, treatment can be effectively maintained throughout the retrofit process. This technique can also minimize regulatory efforts as the plant can likely continue using the same discharge location (for wastewater) or distribution system (for water) already used by the existing facility.
  • Repurpose capabilities: Repurposing existing structural elements of a wastewater or water treatment plant is often a way to offer significant cost savings. Many of the plant’s elements, such as large concrete basins, piping networks and electrical power systems, have a considerably long life cycle.
  • Reliable security: A certain amount of risk is assumed every time a construction project starts, especially with work on a facility critical for such a vital community resource. Public infrastructure continues to face serious threats from terrorism or other disasters that could impact the reliability of a potable water supply and/or sanitary sewer treatment for communities of all sizes. While all plans should be reassessed during a retrofit process, renovating a facility with a foundation of security measures already in place can help alleviate concerns and preserve public safety.

Cutting-Edge Technology Advancements

With effective solutions to treatment and processing, other innovative technologies can be applied during the execution of retrofit projects to save additional time and money. Light imaging detection and ranging, or LiDAR, is a survey tool that provides engineers with a clear picture of the space being modified. Traditional survey techniques gather limited points of a room for planning purposes, while LiDAR gathers thousands of points for a more precise picture of a space. Retrofitting an existing facility requires accurate, detailed measurements to make sure new equipment and processes critical to the renovation not only fit into existing spaces, but can be installed without adding costly doors, hatches or other building openings.

The ability to transform ideas into a visual example can lead to better communication throughout a retrofit project. Using 3D design to construct realistic models allows engineers and builders to create a clear picture of the project outcome. The detailed designs help to better communicate the retrofit vision to city officials or other stakeholders overseeing the project implementation.

A Complex Challenge Well-Suited for Design-Build

Engineers of varying specialties are assigned to look at both the big picture and details needed for a successful retrofit of an aging facility. Utilizing a streamlined approach to the project, a diverse design-build team incorporates the knowledge needed to examine both the big picture and details needed to solve retrofitting challenges and get the project done quickly.

Retrofitting is an efficient way to see that facilities meet the treatment needs of the community while consistently complying with stringent state regulations. Although many aspects of a facility may need to be modified and/or rehabilitated, the core of the existing facility — often constructed of concrete, block, brick and other lasting building materials — provides a money-saving base to start renovations.


There is no one-size-fits-all solution when it comes to solving retrofit challenges in the water and wastewater industry. Learn more about retrofitting your aging infrastructure.

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Kerrie Greenfelder, PE, DBIA, is a municipal water department manager at Burns & McDonnell. She has more than two decades of experience in design-build for water/wastewater treatment, and in landfill design and construction. She's been involved in providing design and management for design-build projects for a variety of municipal, public, industrial and federal clients. She is an active leader with the Water Environment Federation (WEF), Society of Women Engineers (SWE), and the Kansas Society of Professional Engineers (KSPE).