Located in Duluth, Minnesota, the St. Louis River estuary and its tributaries comprise a U.S. Environmental Protection Agency (EPA) Great Lakes Area of Concern (AOC), including Spirit Lake, a large open water portion of the river at a former manufacturing site. In 2011, a confidential client hired Barr to assist with addressing state regulator concerns regarding the site’s aquatic portions. Barr led sediment investigations to update the conceptual site model, assess physical and chemical sediment characteristics, groundwater-surface water interaction, and hydrodynamic conditions to inform remedial design strategies.

We recommended a partnership with the EPA’s Great Lakes National Program Office (GLNPO) under the Great Lakes Legacy Act (GLLA) to implement the design. When the EPA joined the project through a GLLA cost-sharing agreement, one of its national consultants, EA Engineering Science and Technology, Inc., PBC, asked Barr to join the design team. Our key activities included designing sediment remediation for the former coke-settling basin, involving reshaping a historical earthen dam, and developing restoration plans for a meandering stream.

Remedial construction concluded in 2024, a major step toward delisting the St. Louis River as an AOC. The project remediated 1.3 million cubic yards of impacted material, restored 200-plus acres of aquatic habitat, dredged 460,000 cubic yards of sediment and soil, and installed 96 acres of subaqueous caps. Additional work included two on-site confined disposal facilities (CDFs), extensive habitat plantings, realignment of 3,500 feet of stream channel, 6,400 feet of shoreline protection, and creation of a 14-acre sheltered bay for fish-spawning habitat.

Following the accidental release of crumb rubber and field turf into Washington State’s Puyallup River during the in-water construction of a hydroelectric dam project in 2020, civil and criminal lawsuits were filed against the dam owner and operator, Electron Hydro LLC. The lawsuits, brought by the US EPA and the State of Washington, alleged that the release of 4-6 cubic yards of crumb rubber and at least 600 square yards of field turf violated the Clean Water Act, as well as multiple state statutes, and resulted in adverse effects on endangered species. Counsel retained a team from Windward Environmental LLC, now part of Barr,  to provide expert testimony in support of both legal cases.

The potential toxicity of crumb rubber in aquatic environments has drawn attention in recent years, particularly in the Pacific Northwest, following observations of abnormal salmon behavior and salmon mortality during rain events. Urban stormwater runoff, which can carry rubber-tire-related pollutants into waterways, has been linked to high death rates in adult coho salmon. A key chemical of concern is 6PPD, used in tires to prevent cracking. When it reacts with ozone, it forms 6PPD-Q, a compound that can be toxic to juvenile coho salmon.

We used a risk-based biological assessment approach to evaluate whether aquatic species were harmed by the accidental release. Environmental harm was evaluated through an assessment of exposure, concentration, and duration. This assessment included an evaluation of published dose-response data for juvenile coho salmon and 6 PPD-Q, a critical review of an approach for estimating 6 PPD-Q concentrations and potential toxicity, an applicability assessment of toxicity test data, and a close examination of key fate and transport assumptions. 

The team produced expert reports detailing the findings, and a team lead was deposed in both the civil and criminal cases. Both lawsuits were successfully settled prior to trial.

The Rapidan Dam, built in 1910 by Consumers Power Company (now Xcel Energy) to generate hydroelectricity, has served the 2,430-square-mile Blue Earth River watershed for over a century. The 456-foot-long and 87-foot-high hollow Ambursen buttress dam consists of a powerhouse with integral intakes, a spillway section including five tainter gates, and the east and west non-overflow sections and abutments.

After a flood in 1965 damaged hydroelectric operations, Blue Earth County took ownership of the dam and reservoir lands in 1975. While hydropower generation was redeveloped in the 1980s, the dam has faced persistent structural issues and costly repairs, primarily due to repeated flooding and erosion.

Despite temporary risk reduction from emergency repairs and subsequent projects over the years, a catastrophic flood following historic rainfall in June 2024 led to debris accumulation and the river overtopping the dam, causing failure of the west abutment. This triggered riverbank erosion, property damage, and power outages, leading the county board to pursue dam removal. Barr is currently collaborating with local, state, and federal agencies to assess the overall damage and develop plans for the dam removal, river channel restoration, and west abutment and slope reconstruction.

Barr created a HEC-RAS 2D model to guide the design by determining channel velocities and shear stresses. But designing the removal and restoration presents several complex challenges. A nearby upstream bridge was also significantly damaged by the flood. Its replacement is being designed by others on a separate timeline from the dam removal. The initial river restoration concept included a mile of heavily riprapped channel that was necessary to protect the bridge foundations but also carried a high price tag. In coordination with the bridge design team, county staff, and regulatory agencies, Barr developed other options for the channel restoration to lower the overall cost. The bridge design was revised by the bridge design team to incorporate deep drilled shaft foundations extending below the anticipated channel scour elevation, addressing the highly erodible nature of the area’s Jordan sandstone and allowing the mile of channel riprap to be significantly reduced from the design. Significantly reducing channel riprap will allow for natural channel development.

In addition, Barr conducted a geotechnical investigation to support the west abutment and slope reconstruction. The investigation will also inform property restoration, public outreach and park re-establishment conceptual design, and water access along the west embankment and slope.

The design phase of the Rapidan Dam removal project is currently underway. Its success will depend on the ongoing interdisciplinary coordination between the county, design teams from multiple consultants, and the numerous federal and state agencies involved in the project's permitting and funding. 

Faced with a tight deadline and a 1,500-page draft permit from the Minnesota Pollution Control Agency (MPCA), the environmental team at Flint Hills Resources’ Pine Bend Refinery needed support reviewing and interpreting proposed changes. They turned to Barr for help identifying key revisions and understanding their implications for upcoming state permitting negotiations. Traditionally, reviewing a permit of this scale would have required weeks of manual work by experienced staff.

To meet this challenge, our team leveraged a custom AI-assisted workflow that combined advanced document processing with our regulatory expertise and deep knowledge of the Pine Bend refinery. Using targeted prompts, the AI tool conducted a line-by-line comparison of the draft and existing permits, flagging state-specific nuances and identifying substantive changes. 

Key steps in our approach:

By integrating AI tools with our technical expertise, Barr delivered:

This project illustrates how thoughtfully deployed AI can enhance our technical expertise, accelerating delivery without compromising quality, and allowing our team to focus on the analysis and strategy that matter most to our clients.

Learn more about our AI-integrated solutions. 

At a large, former mining facility where gold, copper, and cobalt were mined until the late 1960s, three dams retain either water or tailings materials. Barr was hired to perform a third-party dam safety review of the facility. 

Barr reviewed all three dams, including a dam safety risk assessment. This work included leading the review team, the client, and the facility’s dam safety consultant through a potential failure mode analysis to identify, categorize, and provide recommendations for managing relevant dam safety risks. 

The risk review process was developed based on the Potential Failure Mode Analysis (PFMA) of the Federal Energy Regulatory Commission (FERC) dam safety program and the Failure Mode and Effects Analysis (FMEA) of the Canadian Dam Association. The process included brainstorming potential failure modes, evaluating each failure mode to assign a risk category, and identifying potential risk reduction, surveillance, and monitoring measures. Each potential failure mode was categorized by failure type and risk category, and for each potentially viable failure mode, the PFMA team identified risk reduction, surveillance, and monitoring measures. The risk review workshop included representatives of the consultant dam safety team and the site owner’s management, environmental, and operations staff.

When a long-standing client faced a complex permitting question, they turned to Barr for support. The client wanted to understand how the conditions in a current permit compared with those of other industrial facilities across the state, with a specific focus on water quality standards and designated water bodies. Historically, answering a question like this required a team of staff to manually review and summarize hundreds of individual permits, an intensive and time-consuming process. 

Instead, Barr’s team proposed an innovative approach using an AI-assisted workflow to rapidly extract key information from more than 500 permits across Minnesota. We developed a custom natural language processing workflow to extract the data, creating a searchable database of facility discharge information. The database included permit stations and effluent limits, location data, and whether the facility released to a listed water body. Our GIS team then mapped this data, giving the client a clear view of how their permit compared to others across the region. 

The approach delivered timely, targeted insights and created a foundation the client can reuse to answer future regulatory questions. By combining subject-matter expertise with AI-supported tools, we helped the client gain clarity and context faster and more efficiently than before. 

Learn more about our AI-integrated solutions. 

For companies subject to environmental, health, and safety regulations, compliance reporting is no small task, and solutions to help manage those tasks are limited. The low-end option—using Excel spreadsheets to track compliance tasks—is cumbersome and presents control problems. The high-end solution—third-party environmental management information system (EMIS) software—can come with unnecessary complexity and high annual-licensing costs. 

When a midwestern refinery needed help with compliance tracking, Barr provided a solution that hit the sweet spot: a customized task management system using Microsoft Power Automate (Flow), Power BI, and SharePoint. The all-encompassing, cost-effective program tracks numerous types of federal, state, and local compliance data (e.g., Coast Guard, OSHA, EPA, DOT pipeline) for several terminals in two states. Because the refinery was already using Microsoft Power Suite, the integration solution had the benefit of being both economical and familiar to users. 

Key features to make work easier include dashboards, exportable reports, and email notifications and reminders for completing tasks. The easy-to-use system provides:

To build the system, Barr first reviewed the refinery's existing process and documentation for task management and then developed an inventory of tasks tracked with Excel workbooks. The next steps were data conversion, building and testing the system, and providing support during implementation. For the refinery, moving from spreadsheets to dashboards was a huge step forward in making compliance tracking simpler, more efficient, and more accurate. The timeline for taking that big step? A mere eight weeks. 

Risk-informed design is conducive to sustainable closure design

A mining client ceased mining operations at the end of the 20th century but maintained its tailings storage facility for some time. Barr was retained in advance of an impending regulatory closure and decommissioning deadline to assist in the development and implementation of a plan for closure of the tailings facility. We developed alternatives for future closure plans in accordance with Canadian Dam Association guidance and international best practices and assisted in ongoing operations to lay the groundwork for closure in parallel with final design.

In 2021, Barr developed several conceptual design options for closing the facility and managing residual wastes, which included developing detailed material and water balances for the site, modeling closure scenarios, and presenting alternatives to the client and regulators. The option for sustainable closure and eventual relinquishment of the site that was selected involved drying, blending, and placing the residual waste materials in an isolating containment structure at the highest point of the TSF boundary. This approach is intended to provide long-term physical and chemical stability for the former TSF area, eliminate long-term active care, and support natural ecological systems.

Detailed engineering and design work began in 2023 when Barr designed an impervious cover and prepared a vegetation plan to manage erosion risks temporarily during the transitional and active closure phases. We investigated impacted soils and water on the larger mine site and within the TSF to define the extent of contamination, to assess borrow material suitability for reuse, and to perform engineering and design services for: 

This site posed additional challenges, such as the need to maintain an operational pond and pumphouse within the bounds of the TSF during and following closure, which required detailed sequencing planning to maintain containment during all closure phases and avoid unnecessary environmental impact outside the TSF.

This robust approach to closure planning and design for the facility led to approvals from the regulator to proceed with closure and decommissioning activities for the facility. Detailed engineering and design have been completed and construction is anticipated to begin no later than 2026.

In 2009, the U.S. Environmental Protection Agency enacted a rule requiring the mandatory reporting of greenhouse gases (GHGs) from significant emissions sources across the nation. Facilities emitting 25,000 metric tons or more of carbon dioxide equivalent (CO2e) annually must comply with the comprehensive reporting framework outlined in 40 CFR Part 98 Subpart W, referred to as the Greenhouse Gas Reporting Program. The program is intended to provide a detailed and accurate portrayal of emissions from key market sectors and guide development of policies and initiatives to curb GHG emissions.

Compliance with Subpart W is intricate and rigorous, particularly for energy companies like Summit Midstream Corporation, which must meticulously report emissions from its extensive network of petroleum and natural-gas gathering and boosting basins, as well as natural-gas processing plants. Summit relies on Barr’s comprehensive emissions-reporting services to simplify compliance and help ensure timely and accurate reporting. 

Our assistance incorporates cutting-edge tools and expert analysis to address every aspect of the program, from data collection to final submittals, including:

Adding to the challenge of complying with Subpart W is the EPA’s annual March 31 reporting deadline, which requires a swift and precise reporting effort for the previous year’s emissions data. Because Barr has in-depth familiarity with both the regulatory framework and Summit’s data, however, we can help the company effectively mitigate deadline pressure and help ensure a seamless submittal process.

Since 2023, Barr Engineering Co. has been providing engineering and environmental services to Nevada Gold Mines (NGM). 

NGM hired Barr to study air emissions from three facilities: the roaster at the Gold Quarry mine and the roaster and autoclave at the Goldstrike mine. The company wanted to understand whether increasing throughput at the three facilities would jeopardize compliance with the limits specified in their air permits. The goal of the study was to determine how expanded operations might affect compliance with air emission limits at facilities that use performance testing or continuous emission-monitoring systems (CEMS) to measure emissions. 

Barr took a five-step approach to completing the evaluation: 

  1. Summarized baseline emissions from five years’ worth of performance-test data and CEMS data, where applicable.

     

  2. Created a preliminary estimate of future emissions by employing descriptive statistics and projected future operating rates.
     
     
  3. Assessed the risk of emissions exceeding permit limits at each source to determine where additional analysis was warranted.

     

  4. To recommend the most promising strategies for lowering the risk of exceedances, developed multiple linear-regression models for further studying the impact of future operating rates on emissions; better assessing the compliance risk for emission sources flagged in step 3; and evaluating the degree to which modifying processes might maintain or reduce emissions. 

     

  5. Identify potential actions such as combustion tuning, process optimization, process modifications, and emissions testing campaigns that could minimize the potential for exceeding permitted emission limits.