Dispersion modeling may be required by regulatory agencies when industrial facilities undertake physical expansions or increases in production rates. The modeling is used to demonstrate that the facility will comply with ambient air quality standards (AAQS). The standards are periodically reviewed and revised by regulatory agencies, as are the dispersion models themselves and guidance for their use. It may have been many years since a facility has conducted modeling, or the facility may never have been required to model. Modeling demonstrations can be a time-consuming element of a permitting project.

At five ethanol production facilities located in three midwestern states, Barr was hired to conduct preliminary dispersion modeling for coarse particulates (PM10), fine particulates (PM2.5), and nitrogen dioxide (NO2). The modeling was not required by any agency at the time of the project but was conducted to identify sites and sources that may pose a challenge to demonstrating compliance with AAQS when future projects are pursued and to get a head start on identifying potential model refinements that would address the issues. A culpability analysis of the results was developed to identify the critical sources and focus the refinements. The analysis allowed our client to plan for projects that would require additional measures to meet AAQS.

A confidential energy client wanted to construct a pumped-storage hydroelectric facility at a former mining property. To convert the site into an operating facility, additional features were required, such as saddle dams, reservoir lining, and slope stabilization. The preliminary design also included underground works comprising pressure tunnels connecting the reservoirs through a cavern that houses turbines and generators along with an elevator shaft. The design of each of these features required extensive geotechnical investigation.

Barr was hired to conduct the first phase of the geotechnical investigation, which focused on a subsurface investigation for the proposed powerhouse location, geologic mapping of the proposed tunnel alignment, and remote sensing of the open pits. Based on the preliminary design of the powerhouse, it would require a relatively large volume of competent rock for construction. Barr’s primary goal for the geotechnical investigation focused on gathering data to determine if this block of competent rock was present.

An alternative-energy facility in Minnesota generates 8 MW of power from food-processing wastes and livestock manure. Biogas generated by anaerobic digestion is used as fuel in four on-site 2,000 kW engine gensets that supply electric power to the local community. The digestate is sold to local farmers for land application as fertilizer.

Initially, Barr assisted our client by providing support for an environmental review and permits for air, wastewater, stormwater, and water supply. Subsequently, we were hired to provide facility engineering design and support for procurement and bidding and construction. Facility features included a large receiving hall, materials-handling systems, shredders, anaerobic digesters, biogas storage tanks, gas blowers, gas flares, sludge-drying equipment, and the gas-fired engine generators.

The project received national recognition as “Biogas Project of the Year” by the American Biogas Council. It was also featured in POWER Magazine. You can read the full article online here.

Big Island on Minnesota’s Lake Minnetonka features a 56-acre rustic park and a shoreline with steep, eroding banks up to 60 feet high. The city of Orono, Three Rivers Park District, and Minnehaha Creek Watershed District wanted to prevent further bank failure and loss of natural habitat without posing a significant threat to water quality. 

The first stage of Barr’s shoreline stabilization and restoration involved creating a shore bench of fieldstone riprap and backfill slightly above normal water levels to protect the toe of approximately 3,000 feet of extremely steep or near-vertical banks around the island. Our bioengineering techniques were installed within areas of backfill and along other more gradual banks during the second stage of the project for an additional 1,200 feet of stabilized shorelines and slopes. 

Since its completion, the project has renewed life on Big Island by protecting the littoral zone where fish lay eggs, insects hatch, and plants grow; improving the water quality around the island; and protecting the shoreline for wildlife habitat.

Canada’s Oil Sands Innovation Alliance (COSIA) is an alliance of 10 oil sands producers in Canada’s oil sands. There is a need to understand how species at risk (SAR) pose significant business risk to the oil sands industry. Barr created a priority list of SAR by ranking the species by the factors that contribute to a species being a high risk to the oil sands industry. The business risk assessment was calculated by:

  1. Understanding the interaction between oil sands activities and the key threats (stressors) related to a species’ population decline.

  2. Assessing a SAR’s potential impacts on business categories such as compliance requirements, land and resource access, social license, media influence on public image, operational requirements, and financial resources.

The assessment helped COSIA better understand the risks of SAR’s to the industry and aided in strategic planning.

Pictured below are some of the species included in the assessment; boreal caribou, great gray owl, grizzly bear, northern leopard frog, olive-sided flycatcher, and wolverine.

Anticipating the closure of the Ford assembly plant in 2011, the CRWD, the City of Saint Paul, and Barr developed a redevelopment plan for the 134-acre property along the Mississippi River. Following a feasibility study, Barr developed master-plan concepts for managing stormwater and converting the site into a public space. We created a decision-support framework to help the city and stakeholders compare two stormwater management options for the site—a conventional approach with distributed underground infrastructure and a regional approach incorporating a green-infrastructure corridor that would help achieve the city’s vision of sustainable site development. Each option was evaluated in light of our clients’ stormwater management, sustainability, redevelopment, creek-restoration, and place-making goals.

In addition to a traditional cost-benefit analysis, Barr conducted an innovative life cycle-cost and -impact assessment that monetized socioeconomic benefits. We assessed factors such as water quality and quantity, flood-risk reduction, recreation and property values, and water, carbon, and energy footprints. A comparison of the two options revealed that a green-infrastructure corridor more than doubled the value of the conventional approach while enhancing the site’s public amenities. The master plan combines multiple stormwater treatment BMPs to reduce runoff volume and improve water quality. It details several low-impact stormwater BMPs, including rain gardens, regional infiltration basins, and filtration treatment basins. In 2017, the Saint Paul city council approved zoning so that the property could be developed, providing an opportunity to connect a mixed-use community space to the riverfront and a regional park system.

Barr’s alternative analysis report can be viewed at: https://www.capitolregionwd.org/wp-content/uploads/2018/10/Ford-Site-Sustainable-Stormwater-Management-August-2016-reduced.pdf

Abbott Northwestern Hospital wanted its grounds and outdoor spaces to reflect the care and healing provided within the hospital. To accomplish this, Abbott worked with Barr to create a sustainable landscape master plan. Barr helped the hospital articulate the sustainable landscape goals to guide the plan and to maximize the use of the limited outdoor space. Goals include:

The completed sustainable landscape master plan provided a broad overview of the hospital campus, identifying areas of potential sustainable landscape improvements. Divided into three parts, this overview distinguished between existing pavement, existing roof, and potential landscape opportunities. Barr developed improvement suggestions for each area.

The remainder of the plan detailed an opportunity guide for these spaces. The primary opportunities included designing restful healing spaces; creating a welcoming entry; preserving and developing tree canopy; reducing hard surfaces; managing stormwater in landscape to make good use of runoff; and considering rooftop opportunities.

Ready to build and enjoy the results of the sustainable landscape retrofit projects, Abbott moved into the implementation phase in 2022.

A confidential client wanted to evaluate methanol-injection system equipment at a meter and pressure control facility to determine its ability to operate in the installed conditions and according to the operating strategy, the desired control scheme alignment, and its characteristic operational effectiveness. The energy producer also wanted an evaluation of line heater installations and piping modifications for storage withdrawal at an additional meter and regulation site for ways to increase the reliability of the gas withdrawal cycle.

Barr was retained to perform a two-phased engineering study. First, Barr performed a site assessment of the methanol injection system as installed to document the existing piping, equipment, and control system and to predict potential site construction and operational constraints. We also examined the system for its ability to operate by reviewing equipment documentation for chemical compatibility, modeling for system flow anomalies, and documenting historical operating conditions.

We then analyzed the two sites for the potential value of adding equipment or systems to remove, condition, or chemically alter the flow stream to reduce hydrate formation from entrained liquids at pipeline-pressure-reduction control valves. Barr worked through the multiple gas conditioning options including centrifugal and two-phase separation, Joules-Thompson effect thermal heaters, chemical injection at wellhead locations, gas dehydration by TEG or molecular-sieve/desiccant, and piping modification to reduce turbulent flow conditions within the gas stream. All options were evaluated on a scale for initial capital investment by the client.

In a final report, Barr detailed recommendations for improving the gas withdrawal system for safer and more reliable pipeline operation. We also offered a “further analysis recommendation” to aid in building a technically complete package for proposals to conditioning equipment vendors.

With the goal of developing solar plants throughout Minnesota, Ameresco (with GreenMark Enterprises) hired Barr to determine adequate locations for development by performing a feasibility review of each site. The review was divided into five categories: water, vegetation, cultural, geology, and topography. The sites were reviewed for various factors, including impacts from floodplains, impaired waters, threatened and endangered species, wetlands, and cultural impacts. Soil data was evaluated for issues related to soil strength, foundation construction, and foundation stability. Topographic data was used to evaluate slope direction and steepness. The review culminated in a summary report for the client’s review and use in identifying ideal sites for solar development.

In 2020, the City of Winona wrote the Bluffs Traverse Master Plan, a roadmap for recreation and park uses that recommended ecological planning to balance park enjoyment with ecological preservation. As a first step, the city hired Barr to conduct a natural resources inventory and develop a stewardship plan to help the city and stakeholders better understand the park’s native plant communities and determine the best placement of trails.

Our work began with a plant community inventory using the Minnesota Land Cover Classification System (MLCCS). After identifying plant communities, Barr’s field ecologists evaluated each plant community for ecological quality, noting areas of exceptional plant diversity and the degree of invasive species encroachment. GPS tracking technology helped provide precise locations of these communities as well as areas of significant erosion.

Barr then developed the stewardship plan, which provided a strategy for protecting the park’s high-quality ecological areas, placement of trails, and a phased approach to restoring native plant communities. Because Bluffs Traverse encompasses a large area (six miles in length and 523 acres), it was important for the stewardship plan to prioritize areas with the greatest potential for rehabilitation within a limited city budget. The plan also included protective measures for the timber rattlesnake, a threatened species in southeastern Minnesota.