In 2012, more than nine inches of rain caused significant flooding and infrastructure damage in Duluth. Barr provided evaluation and design services for a damaged reach on Coffee Creek, a popular trout stream that runs through Enger Park Golf Course. We worked with the city to obtain funding to stabilize and restore the most severely damaged section through a former irrigation pond. Using natural channel design principles, Barr designed restoration of the stream’s pattern, profile, and dimension to emulate a stable reference condition, protect infrastructure, stabilize streambanks, and improve trout habitat. We also conducted hydraulic modeling to confirm that channel dimensions and materials would resist bankfull flow velocities and to support FEMA permitting for changes to the floodplain. 

Design, permitting, and construction for restoration of 1,200 feet of channel were completed in 2015. Barr observed construction, which entailed daylighting 250 feet of stream previously confined to an undersized culvert and realigning the channel within the bed of a former irrigation pond. At the former pond outlet, we designed a permanent stream crossing that allows for fish passage at bankfull flows. The bankfull-width box culvert contains a natural-material streambed and was evaluated using FishXing and HEC-RAS. Barr prepared a FEMA letter of map revision, which became effective in March 2017 and reflects a modified (mostly lowered) floodplain elevation. 

The Federal Energy Regulatory Commission (FERC) requires renewal of hydropower dam licenses approximately every 30 years to help evaluate many factors associated with a dam’s continued operation. When it came time to relicense the Ford Lake Dam, Ypsilanti Township called on Barr.

The relicensing process took approximately five years. To build consensus on the licensing conditions and identify potential concerns, Barr began by soliciting input from stakeholders—many opposed to dam relicensing. Stakeholders included nearby residents, river advocacy organizations, and regulatory agencies. Based on this input, we collected data on the water quality and aquatic vegetation in the upstream reservoir and downstream Huron River; we assessed the fisheries and mussel populations; and we studied the wildlife and botanical resources in the surrounding riparian lands. Cultural studies revealed the powerhouse qualified for the National Register of Historic Places.

The Michigan Department of Environmental Quality, state Department of Natural Resources, and U.S. Fish and Wildlife Service used results from the studies to propose license conditions for the facility’s continued operation. Barr helped the township negotiate license conditions that would protect stakeholder interests at an affordable cost to the township. Since FERC’s issuing of the license, Barr has been working with Ypsilanti Township to implement and monitor the license’s mandated conditions.

Barr continues to act as the Township’s Dam Safety Engineer. We work closely with the Township preparing their annual FERC Dam Safety Surveillance and Monitoring Report and Plan updates. We facilitate the Tabletop and Functional Exercises of the Emergency Action Plan (EAP), and assist the Township with annual updates to their EAP.

In June 2014, a record storm caused 10,000 square feet of the Mississippi River bluff to fail, burying West River Parkway and exposing hospital infrastructure. The Minneapolis Park and Recreation Board hired Barr to monitor slope and infrastructure stability and then design and observe construction of repairs. Work was complicated by the extremely steep slope; limited access; seepage; weak soils; stability concerns; and an active hospital facility with loading, noise, and emissions restrictions. Barr integrated soil nails and five retaining walls to design a unified stabilization system and specified low-vibration installation techniques to curtail the potential of additional slides. Completed under budget, the project helped ensure public safety without interrupting hospital operations. The parkway reopened for commuters and cyclists on September 16, 2016, just in time for the Twin Cities Marathon. 

At a former industrial site, the manufacturing buildings were removed in the 1990s, and a trichloroethylene (TCE) plume was discovered under one of the newly redeveloped buildings. Because two aging air-sparge remediation systems were expensive to operate and maintain, were not reducing source mass, and were not addressing potential vapor intrusion concerns, the responsible party hired Barr to conduct a remedial investigation and evaluate options for reducing the contamination. 

Barr performed a subsurface investigation of one of the source areas, which was located under an existing building. We delineated a treatment zone and provided the necessary data for designing a remedy that would address movement of the source mass from under the building. We performed high-resolution characterization using membrane-interface/hydraulic profiling tool (MiHPT) boring and confirmed the results with soil samples and chemical and hydraulic analyses. Monitoring wells were installed to assess baseline geochemical conditions and contaminant concentrations in the groundwater. 

We designed a “biobarrier” remedy with a multi-mechanism approach to reduce contaminant movement. The design included injection of four amendments—an adsorption mechanism, an abiotic mechanism, and a dual-amendment biological mechanism—and verification of proper distribution of the amendments using soil borings and piezometers in the vicinity of the injection locations. 

Results indicate the biobarrier performed as designed. Movement of TCE to the primary well downgradient of the biobarrier was reduced by up to 99.5 percent. Lessons learned from the biobarrier implementation were applied to a second source area at the site, which included extending the original biobarrier as well as applying the multi-mechanism remedy to the second source area. Performance monitoring is ongoing and indicates the source area remedy and extended biobarrier are reducing contaminant mass in and downgradient of the second source area.

A Canadian oil sands mine is demonstrating that water-capped tailings technology can be used to convert a former tailings basin into a lake similar in appearance and function as other regional lakes. Since 2014, Barr has been conducting monitoring and physical assessments of the fluid fine tailings in this demonstration pit lake. Our work includes using data generated from annual sonar surveys to determine the top of the tailings’ surface; estimating water and tailings volumes, water-cap depth, and rate of settlement; and annual reporting on changes over time. Tailings samples are periodically collected throughout the lake and submitted for physical laboratory testing. In addition, we are analyzing tailings characteristics to determine changes in various properties over time. In-situ geotechnical testing consisting of cone penetration tests and vane shear testing are also performed periodically to determine changes in the tailings consistency over time.

In 2015, Barr established a program to monitor shoreline erosion and has since performed annual assessments and program refinements. Elements of the program have included  inspecting shoreline conditions, installing a wave gauge, using weather-station data to create annual “wind roses” with air-dispersion modeling, using a spectral wave-prediction model called SWAN to compute general wave characteristics, modeling local sediment transport and erosion, combining lake bathymetry for sonar survey and LiDAR topography, determining erosion rates over time, and preparing periodic reports and recommendations.

Barr has conducted drinking water risk and resiliency assessments (RRA) and developed emergency response plans (ERP) for the cities of Victoria, Bloomington, Fridley, New Brighton, and Richfield and Owatonna Public Utilities in Minnesota to meet the America’s Water Infrastructure Act (AWIA) requirements. The primary purpose of the AWIA, administered and enforced by the EPA, is to improve drinking water and water quality, increase infrastructure investments, and enhance public health. Barr’s services included conducting RRAs to assess, manage, and mitigate potential risks and identify areas of resiliency for drinking water utilities. We evaluated potential risks of natural hazards and malevolent acts to water utility infrastructure. Our services also included developing and/or updating ERPs, including tabletop exercises, to prepare drinking water utilities for emergencies. The ERPs incorporated the results of the RRAs and included plans, procedures, communication information, and identification of equipment that can be used in the event of a natural hazard or malevolent act or other emergency event on the water system.

These projects provided valuable information on potential security and cybersecurity risks to the water system and updated emergency response plans while saving clients valuable time and providing our knowledge and expertise.  Because this was newer requirement. city clients were uncertain how to proceed and appreciated Barr’s guidance throughout the process, such as developing risk and resiliency assessments, and updating and/or developing emergency response plans. Barr staff members are trained by the EPA in AWIA requirements and are AWWA certified.

Reviewing the reciprocating internal combustion engine (RICE) inventory for an oil and gas client

A confidential client owns and operates hundreds of reciprocating internal combustion engines (RICE) across the country at its various oil and gas facilities. The client hired Barr to complete a comprehensive regulatory-applicability review of the client’s engine inventory and audit of its compliance programs with regards to the applicable state, federal, and county air quality regulations and associated air quality permits. The intent of the audit was to demonstrate whether the client was correctly determining regulatory applicability and that its RICE compliance program and practices are consistent with industry standards.

Barr reviewed the client’s existing process for determining engine applicability, created compliance tasks, provided recommendations for process improvements, and confirmed that the process adequately applies requirements and tasks to each type of engine. Significant challenges included managing the large number of engines, the many different regulatory jurisdictions (states), and the large amounts of associated data. Collaborative and consistent communication between Barr and the client allowed us to help the client transition its audit policy from a site-by-site process to a program-wide approach.

The Utah Department of Air Quality (UDAQ) asked Barr’s confidential client to prepare a reasonably available control technology (RACT) analysis to support their development of an updated state implementation plan (SIP). A SIP update is required when an area does not achieve the national ambient air quality standard for a particular pollutant by a regulatory deadline. When the severity of the non-attainment changes, a new SIP is required. The RACT analysis was for nitrogen oxides (NOx) and volatile organic compounds (VOC) emissions from a refinery in Salt Lake City to support of the UDAQ’s moderate ozone SIP published in 2023.

The analysis relied on prior control evaluations under RACT and best available control technology (BACT) completed under Utah’s moderate and severe PM_2.5 (particulate matter) SIPs dating back to 2012. The historical analyses conducted for the PM_2.5 SIP evaluated NOx, VOC, sulfur dioxide (SO₂), and PM_2.5 controls. Barr refreshed the historical analysis and evaluated all refinery equipment, including the fluid catalytic cracking unit, wastewater treatment plant, fuel gas combustion devices, storage tanks, and transfer racks. Controls evaluated included selective catalytic reduction, selective non-catalytic reduction, ultra-low NOx burners, LoTOx, closed-vent vapor recovery systems with carbon or combustion, secondary seals on internal floating roof tanks, and retrofitted domes on external floating roof tanks. Barr worked with refinery staff to confirm that their feasibility arguments for possible future controls were technically sound and their cost estimates were defensible and took into account site-specific nuances. Due to the depth of the analysis, the UDAQ had very few questions regarding the RACT report.

Barr’s support of the client did not end there. Similar to the work conducted for the PM_2.5 SIP, Barr helped the refinery address agency proposals, reviewed the draft SIP, and prepared public comments on behalf of the refinery. Given Barr’s technical experience with refinery design and operations and the resulting air quality impacts, Barr was able to prepare public comments that addressed the technical, economic, and legal feasibility of “beyond RACT” controls proposed by the draft ozone SIP.

An industrial sand producer historically disposed of its fine tailings by slurrying them to old mine pits, but over time, the pits’ capacity for tailings disposal became unsustainable. Around the same time, one of its tailings basin dams failed due to uncontrolled seepage.

Barr was hired to provide emergency response for the dam failure and to evaluate alternative tailings-management approaches. We conducted an alternatives analysis, and the use of dry-stack tailings was identified as the preferred alternative to slurry tailings. Barr designed the filter plant to dewater the tailings and improve stability of tailings, providing all civil, structural, mechanical, and electrical engineering and design; process flow diagrams; and civil and mechanical layouts for bidding and construction.

At their facility in Romeo, Michigan, Romeo RIM manufactures plastic components such as bumpers, fascia, side panels, hoods and engine cowlings for trucks, recreational vehicles, and tractors/heavy equipment, as well as components for other consumer products. Products are made of polyurethane and other materials using reaction injection molding (RIM) equipment. These operations occur in a closed mold (also known as a clamp), where a resin and a catalyst are injected into the mold to react and form a solid plastic component. The facility is an existing Title V major source for both volatile organic compounds (VOCs) and hazardous air pollutants (HAPs), and Macomb County is currently classified as a non-attainment area for ozone.

Romeo RIM planned to decommission three RIM clamps and relocate two remaining RIM clamps to provide space for new production equipment and operations. Barr developed permit to install (PTI) application materials for the decommissioning and evaluated the effects of relocation of the two remaining clamps under Michigan air rules exemptions as a non-meaningful change to a source of toxic air contaminants (TAC). This allowed decommissioning and relocation activities to begin immediately.

When Romeo RIM subsequently planned to install two new RIM clamps to produce exterior body components for delivery trucks, Barr assisted in evaluating the project and determined a PTI application was required. The evaluation included working closely with chemists and production specialists from the resin-package supplier to assess the minimal VOC emissions associated with the reaction and to estimate potential VOC emissions assuming maximum operating levels.

To minimize Romeo RIM’s air permitting and compliance obligations, avoiding those required by non-attainment New Source Review (NSR), Barr developed synthetic minor emission limits and associated operational limits for the PTI application. These proposed permit conditions allowed sufficient flexibility for the planned production levels and allowed for future increase in production levels. Barr evaluated TAC ambient impact levels and best available control technology (BACT) requirements for TAC and VOCs to confirm the operation and associated emissions meet applicable Michigan air rules requirements.

Additionally, we assessed the compliance of project HAP emissions under the National Emission Standards for Hazardous Air Pollutants for Surface Coating of Plastic Parts and Products (NESHAP PPPP) for the coating of miscellaneous plastic parts and incorporated the equipment and operations into the facility’s existing PPPP compliance program.