In early 2015, the City of Hastings began revitalizing its downtown. The first stage of the project involved redeveloping Levee Park on the Mississippi River, just north of historic downtown Hastings. Barr partnered with the city and Bolton & Menk, Inc. (a civil and landscape design consultant) to design and install new LED lighting systems. Barr’s design team also helped replace the 30-year-old lighting along Second Street with new LED lighting retrofits.

The new LED lighting system is most notable for its efficiency. While designing the system to meet Illuminating Engineering Society (IES) standard “commercial collector” criteria, Barr was able to reduce the wattage to one-fourth of what the old, high-pressure, sodium-lamped system used.

In addition to the increased efficiency, the new system can also be dimmed for more energy savings and extended LED life. The city further took advantage of this feature by employing lighting-control technology, which enables each luminaire to be separately controlled and dimmed using a graphical interface.

The lighting control system employs a head-end smart-server, which communicates over the power wiring to a module in the base of each pole. Poles and luminaires can be assigned to groups depending on the needs of the city. The system also detects the amount of energy being used, whether the luminaires are operational, and any anomalies or flaws.

Seeking to inform future decision making related to risk mitigation and environmental stewardship, Nutrien retained Barr to complete a system inventory and semiquantitative risk analysis (SQRA) for its more than 100 earthen dike segments across six potash mines in Saskatchewan, Canada.

Barr first completed an inventory of each dike noting their differing history, physical characteristics, operations, and failure consequences. With established background, Barr then developed a SQRA system to analyze fine tailings and brine containment dikes. Risk for each tailings segment was identified as the product of the relative probability, relative consequence, and uncertainty. A recommended risk response level was determined for various ranges of risk score to allow prioritization of resources and inform recommended actions for ongoing analysis, monitoring, inspections, and other activities to manage the risk associated with each dike. These recommendations consider current Nutrien practices, industry guidelines, and facility approvals to operate.

Inventory and results of the SQRA were then paired with Nutrien’s tailings management objectives to identify dike segments that were priorities for further investigation or in need of analysis or improvements to conform with current risk management approaches. With this SQRA, Nutrien can prioritize the implementation of resources and focused improvements to continue alignment with regulatory requirements and internal company objectives.

Read the May 2022 issue of Mining Engineering Magazine to learn more about this project.

Barr has served as engineer to the Valley Branch Watershed District for half a century. In that time, we have helped design new infrastructure systems and manage and restore natural conveyance systems in the district. One of these systems is a six-mile-long flood control system that created an outlet for landlocked lakes, protecting homes and critical infrastructure from flooding and saving millions of dollars over 30 years. The natural conveyance systems include a high-quality trout stream where the district has completed restoration projects to protect important habitat.

In addition to helping implement capital projects, Barr manages the district’s inspection and maintenance program for its infrastructure and natural conveyance systems, including more than 20 unique systems owned or operated by the district. We communicate with district residents, municipal staff members, and the district’s contractors to enable efficient and safe operation of district-owned or -operated systems. We also conduct utility locates for all of the district’s underground infrastructure.

Barr performed tunnel-inspection services for the City of Minneapolis, including an inspection of the Highway 55 stormwater tunnel near 26th street, which discharges into the Mississippi River. The inspection included approximately 8,000 linear feet of the Highway 55 tunnel and a 600-foot lateral tunnel. Access was coordinated using two different vertical-shaft locations. Barr’s inspection included documenting identified features using National Association of Sewer Service Companies (NASSCO) coding. Barr’s work was completed and submitted to the city under budget.

Barr assisted TransCanada (now TC Energy) with various air-quality permitting and compliance projects throughout 2018 and 2019. Our support included preparing air-emission inventories, developing air-quality inspection forms, reviewing inspection procedures, updating compliance plans, reviewing regulatory applicability determinations, calculating potential emissions, creating a monthly emissions-tracking spreadsheet, assessing permitting history, preparing a Part 70 operating permit application, and providing day-to-day regulatory interpretations and support to environmental staff.

Our support resulted in an improved air-compliance program, a thorough understanding of regulatory requirements by TransCanda environmental staff, and improved tools and procedures for ongoing compliance management.

To assess the ecological quality of natural resources in Burnsville (a southern suburb of Minneapolis) and develop a master plan for their protection, preservation, and management, Barr surveyed the ecological quality of the city’s natural areas. We mapped the entire city to identify land cover types and vulnerable areas, evaluated urban forests, and recommended actions to protect and enhance the local trees and vegetation.

The master plan’s priority recommendations included expanding buckthorn and invasive-species control, establishing a buckthorn brush-pickup program for private landowners, creating a boulevard tree-planting program, conducting a disease program for green ash trees, expanding a maintenance program for younger trees, developing a city-center sustainability demonstration project, and reducing deer populations in selected woodland-restoration areas.

To meet environmental permit requirements, U.S. Steel needed to reduce emissions from the waste-gas discharge stacks of the pelletizing grate at its Keewatin Taconite facility.

Barr designed the layout for the new system, which included new buildings, two wet scrubbers, two fans and motors, process ductwork, effluent handling, and filter-press systems. We also designed new structural supports and foundations for buildings and equipment, effluent piping and pumps, a water treatment system, process ductwork, hydrated lime unloading and storage, and scrubber-sludge handling and loadout, as well as electrical power distribution, instrumentation, and motor control centers.

To minimize disruptions to production, most of the construction took place while the plant was in operation. Barr also provided similar services at U.S. Steel’s Minntac facility to remove the existing emissions-control device and add a new waste-gas scrubber.

Barr assists a potash mining client in Canada with operating its tailings management areas at several facilities by providing long-term deposition planning, new facility design, instrumentation and monitoring assistance, and closure planning. We have investigated alternatives for depositing tailings more effectively to better position the sites for closure and evaluated tailings characteristics for containment and capping. We also identified closure alternatives and are developing designs for one facility that follow the Canadian Dam Association’s guidelines for converting a tailings management area to a landform.

Barr has been providing SaskPower with dam-safety consulting services since 2014, including reviews, audits, and annual inspections in accordance with Canadian Dam Association (CDA) guidelines. For these facilities, which range in generating capacity from 5 MW to 288 MW, we have reviewed dam design, condition, performance, management, and emergency preparedness by conducting field inspections, reviewing historical documentation, evaluating instrumentation data, and completing technical studies. Any deficiencies and nonconformances we identified were prioritized and reported to SaskPower, accompanied by recommended mitigation measures.

Additional services have included embankment repair design, a feasibility assessment for spillway replacement, and hydrotechnical analyses, such as hydraulic modeling for dam-breach evaluations, hydraulic modeling of the Souris River, probable maximum flood (PMF) estimates, and spillway rating-curves analyses.

At its Coal Creek Station facility, Great River Energy was having issues with the chutes and transfer points in its materials-handling system freezing up during the winter months. Additionally, the location of these chutes was prone to frequent wind, and employees did not have local access to proper tools to clean out the frozen chutes. To increase the reliability of its coal-dryer load-out equipment, Barr was contracted to design an enclosure for the transfer points and design electric heating and lighting for this new area. As part of the design, we also designed convenience 120V and 480V power receptacles throughout the project area. 

The new enclosure was designed to tie into existing structure and stair tower framing. The tie-in locations were not lined up and connections were specially designed for this install. Existing floors were used to shelter the new space, and the contractor fit specially designed seals around equipment openings to keep the winter weather out. The project was designed to be installed in phases so the owner could use its own personnel and spread budget over multiple maintenance periods.