Barr has been assisting the RWMWD with repair and rehabilitation of the Beltline and Battle Creek stormwater tunnel systems for more than three decades. Constructed in 1925, the Beltline interceptor captures stormwater from two watersheds through a system of tunnels around 34,000 feet in total length. The Battle Creek system, built in 1982, conveys stormwater flow under the creek via 4,500 feet of tunnels.
Our inspectors, certified by the National Association of Sewer Service Companies (NASSCO), provide regular inspections of the tunnels. In 2015, we conducted a five-year inspection and condition assessment of the entire Beltline and Battle Creek storm tunnel systems. Using a NASSCO PACP inspection approach, we documented structural and operational/maintenance defects. We then used a coding system to assign numerical scores to condition defects based on their seriousness. Observations and defects were catalogued by location IDs linked to station numbers and clock position. Tunnel segments were then evaluated by condition ratings to identify and prioritize those most needing repair.
Barr then developed a rehabilitation design for approximately 16,000 feet of tunnel, including repair details and quantities. We also provided bidding and construction administration and full-time, on-site construction observation. Conducted in two phases over two years, the $4 million project was completed in 2018. Barr performs detailed inspections of the entire seven-mile storm tunnel system every five years.
Barr has provided engineering services for cathodic protection of pipelines for multiple clients and projects. Cathodic protection extends the life of pipelines and other buried facilities by using an impressed-current or sacrificial-anode system to reduce and prevent external corrosion. Our team evaluates, designs, and installs such systems and related monitoring systems.
Our services include developing field-test plans, reviewing and analyzing data and system performance, conducting desktop studies of subsurface conditions, designing new cathodic-protection systems and repairs to existing systems, and designing monitoring and testing systems (coupons, remote monitoring, and test stations). Professional engineers and other cathodic-protection personnel certified by the Association of Materials Protection and Performance (formerly NACE International) oversee system designs and field-data analysis.
Projects Barr has completed include designing an impressed-current system featuring conventional, distributed, deep-well, and linear-anode groundbed elements for hydrocarbon pipelines in several midwestern states. Our work encompassed mainline portions of the pipeline and pump stations and other facilities. For a flood control project in North Dakota, we designed galvanic-anode cathodic-protection systems for pipeline casings and stormwater pipes at critical levee crossings, and designed a system for a chemical pipeline at a highway crossing between a client's facilities in Minnesota.
Barr's expertise has helped several confidential clients reduce maintenance costs and extend the life of their pipelines and related underground facilities.
The city of Lansing, Michigan, asked Barr to develop a more accurate method of calculating non-residential stormwater utility fees than the rough estimates it had been using, which didn’t fairly represent the actual amounts of runoff from individual properties. Our solution was to create a landcover-classification system based on a dataset of high-resolution aerial images, which the city can analyze alongside its parcel data to determine the percentage of each property that is impervious to rainwater (i.e., covered by buildings and/or hard materials like concrete, asphalt, and rocks).
Barr used near-infrared imagery from the USDA’s National Agriculture Imagery Program to identify first the distribution of pervious and impervious surfaces across the city, and then the percent of impervious surface on each non-residential parcel. We also classified the different types of pervious cover (such as grass, trees, and soil). Finally, we helped Lansing staff members clean up the existing parcel data by removing inaccurate or duplicate information before the city appended the new dataset to its parcel information.
This GIS-based method of analyzing properties has given the city of Lansing an accurate, objective way to determine stormwater fees for owners of non-residential land parcels.
The Minneapolis Park and Recreation Board hired Barr to assess native plant communities in Minnehaha Park’s 55-acre lower glen and to plan ecosystem restoration measures. The project specifically addressed bluff stabilization, oak savanna release, control of invasive plant species, and design of trails and structures to help prevent visitors from trampling native plants.
Barr designed a variety of measures to restore the native plant community, which included maple-basswood forest, oak savanna, and floodplain forest habitats. Working with the park board, we developed a practical implementation and management approach that protects natural features and offers long-term maintenance options that can be achieved with the park board’s resources.
After completing a prefeasibility study to determine the viability of making modifications to its processing plant to produce concentrates of copper, lead, and zinc, Ouray Silver Mines (OSM) sought to complete the detailed engineering and construction associated with the new process arrangement. The mine’s existing concentrator plant is located underground and adjacent to the underground mine eight miles east of Ouray, Colorado. The project required both deconstruction and new installation of equipment to achieve steady-state operation and process approximately 276 short tons per day of mined ore.
While OSM and its contractor conducted the reconstruction work and installation of new equipment, Barr provided the detailed engineering to support equipment installation, including general arrangement drawings, detailed plans for foundations, structural supports and access, interconnecting chutes, piping, and electrical and control systems.
Barr developed the preliminary design documents for the prefeasibility study to final design, including updating the design basis; confirming process model balances; updating the existing functional description to incorporate plant upgrades; and developing updated equipment, load, and instrument lists. Barr focused on optimizing and improving the design to reduce cost and schedule and increase productivity.
Through Xcel Energy’s Renewable Energy Research Grant, Barr and the University of Minnesota St. Anthony Falls Laboratory joined together to develop a cost-effective method for evaluating the current health and remaining useful life of a wind turbine’s tower and foundation.
The project objectives were to develop an economically viable and deployable system of sensors that could take the foundation and tower measurements needed to assess health and remaining useful life, as well as a method of utilizing the data obtained along with SCADA data from the wind turbine for this assessment, and then test the sensor system and estimation methods.
A sensor system was developed and installed on a research wind turbine (that Barr previously designed) at the University’s Eolos Wind Energy Research Station. This system showed accuracy and effectiveness similar to the wind turbine’s existing system with project performance achievements that included: 1) an improved installation mobilization time of less than 4 hours per turbine; 2) potential wind-farm cost savings of at least $100,000 over the 20-year life of the turbine versus conventional sensing systems; 3) development of a metric for estimating the remaining useful life of a wind turbine tower and foundation based on wind turbine historical SCADA data; and 4) potential reduction of up to 54% in equipment costs per wind turbine compared to the cost of the existing system.
Barr is now able to utilize the knowledge gained from this project when deploying equipment for client work.
A slow-moving plume of chlorinated solvents extends from a former manufacturing facility northward to a channel connected to Lake Minnetonka in the western Twin Cities area. This plume had been in the subsurface for many years and was being slowly degraded into environmentally safe compounds by natural processes, but the Minnesota Pollution Control Agency (MPCA) was concerned that even a small flow could affect the surface water.
Because a pump-and-treat system would be resource-intensive and alter existing mechanisms, Barr designed a constructed wetland that enhances the already occurring natural attenuation and developed a plan that generated public and MPCA support. Our design included a barrier to passively control and direct groundwater flow through the reconstructed wetland, where mechanisms bio-stimulate the attenuation process.
To address the MPCA’s requirement of four years of wetland performance monitoring to evaluate the effectiveness of the wetland treatment system’s operation and maintenance, Barr developed an innovative performance monitoring program. This included maintaining the wetland’s operation by promoting growth of desired plant species and monitoring the wetland hydraulics, chemicals of concern, wetland geochemistry, and surface water immediately downgradient of the wetland. After four years of performance monitoring, the data showed the wetland operates as designed and provides a permanent, successful, low-cost treatment system while also serving as a park area for the community.
The Southwestern Power Administration’s (SWPA) Poplar Bluff Substation included several pieces of equipment in need of upgrading, so they turned to Barr. We designed a relay panel to replace outdated protection and controls (P&C) and upgrade the remote terminal units (RTUs) and metering equipment.
The substation has two 161kV transmission lines, three 161kV/69kV transformers, and two 69kV feeder lines, using a main-and-transfer configuration on both the 161kV and 69kV buses. The substation configuration also included six 161kV breakers, six 69kV breakers, and one 69kV capacitor bank.
To avoid any outages, SWPA also requested that we create a temporary design and mobile relay panels to maintain service during the panel replacement process for about five weeks. Barr created 6 new drawings and modified 68 existing drawings for the temporary relay design set. A specialized coloring scheme was used to differentiate temporary drawings from final drawings. Our final design modified and created a total of 134 drawings, including one-line and three-line drawings; AC, DC, and RTU schematics; panel layouts (with detailed material lists for panel build), and wiring diagrams. Additionally, a 35-page installation procedure document was prepared providing step-by-step instructions for temporary setup, removals, and final installations and checkouts.
Barr provided relay settings and onsite commissioning support in 2021 during the construction, and construction was completed summer of 2021.
The U.S. Army Corps of Engineers, Detroit District needed to reduce the arc flash incident energy (IE) levels at three of their facilities in Detroit, Michigan; Duluth, Minnesota; and Kewaunee, Wisconsin. Barr was hired to conduct electrical analyses to provide recommendations to reduce the facility personnel’s risk of exposure to electric energy while providing the USACE necessary information to implement mitigation techniques.
Barr performed a power system analysis of the three facility electrical systems, including for a floating plant located on a barge. A task-based assessment (per NEPA 70E requirements) or a detailed IE analysis (based on IEEE 1584) was used at each site, depending on the electrical characteristics of the facility. The IE analysis included a short circuit study and protective device coordination study along with an arc flash hazard (AFH) analysis. All analyses were in compliance with industry standards as well as USACE standards ER 385-1-100 and EP 385-1-100.
Barr performed the IE analysis using SKM System Analysis software and submitted an AFH report to the USACE summarizing the analysis, results, mitigation recommendations, and conclusions.