Case studies

  • Advanced Stormwater Treatment Design & Installation Seattle, WA

    Advanced Stormwater Treatment Design & Installation

    Seattle, WA

    This industrial facility site is handles prefabrication of sheet metal, mechanical piping, and plumbing equipment. The site consists of 3.16 acres, of which 1.47 acres contains industrial activities generating stormwater runoff and is covered under the Washington State Industrial Stormwater General Permit (ISGP).

    SoundEarth services included preparation of the Engineer Report, treatment system design, cost estimation, construction document development, conveyance upgrades, outfall analysis and relocation, treatment feasibility evaluation and Best Management Practice (BMP) installation, construction quality assurance and oversight, site survey and facility mapping, stormwater conveyance investigation, and O&M plan development.

    In response to permit benchmark exceedances, the stormwater system was modified and upgraded to meet the treatment BMP requirements of the ISGP. A feasibility study was performed to determine the best-fit solution meeting the client needs for a small footprint, cost effective, NPDES permit complaint stormwater treatment BMP. The solution included retrofitting the existing stormwater infrastructure and site drainage by plugging a stormwater outfall pipe, redirecting the conveyance piping to combine both drainage areas to one outfall, retrofitting the existing outfall by adding an inline pump vault to direct untreated stormwater to the above ground treatment BMP. The team provided a turn-key solution for this treatment BMPs from conceptual design to commissioning.

    SoundEarth staff created a modular design of above-ground GRATTIX box treatment systems, which allowed for reduced installation and maintenance costs and ability to deploy additional treatment boxes if needed. Runoff from the facility is collected and pumped to above-ground GRATTIX box treatment system which consist of a low impact designed bio-retention and multimedia filtration unit, where sediment, metals and hydrocarbons are removed from stormwater. Our design reduced contaminant loads to permissible levels. SoundEarth staff also provided construction oversight and commissioning.

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  • Jorgensen Forge Stormwater Program Support Services Seattle, WA

    Jorgensen Forge Stormwater Program Support Services

    Seattle, WA

    SoundEarth is currently supporting Jorgensen Forge Corporation by managing the stormwater treatment program at the Jorgensen Forge Outfall Site (JFOS), where PCBs were previously released to the subsurface from leaking stormwater pipes. SoundEarth is supporting their compliance program for the facility’s ISGP and the owner’s upland source control objectives for their 20-acre waterfront industrial facility.

    SoundEarth’s previous work include planning, implementation, and documentation of removal actions and subsequent modifications as part of an emergency response under a CERCLA Administrative Order. SoundEarth prepared the Basis of Design Report for investigation of PCB data gaps under the east bank of the Lower Duwamish Waterway, and completed an angle boring investigation. SoundEarth supported the JFOS engineering design team during design of a cofferdam for use by others in connection with a separate, but adjacent, Early Action Area in-water removal action.

    SoundEarth also helped develop TSCA-compliant waste segregation, disposal, and equipment decontamination protocols and post-construction baseline and monitoring programs. Waste minimization and safe construction logistics were high priority objectives for the planning support efforts. SoundEarth provided construction-phase observation, field documentation, and preparation of formal EPA submittals, including Basis of Design Reports, Work Plans, and Removal Action Completion Reports for the JFOS project. SoundEarth profiled waste streams and documented the removal of corrugated metal pipes and PCB-contaminated soil from above the groundwater table. This work was performed in preparation for removal action activities planned below the groundwater table.

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  • Stormwater Compliance & Program Management Services Seattle, WA

    Stormwater Compliance & Program Management Services

    Seattle, WA

    This industrial facility is responsible for comprehensive waste handling and environmental services. The project site consists of 2.6 acres. For this site, SoundEarth provides stormwater support to effectively manage the requirements outlined in their Ecology issued National Pollution Discharge Elimination System (NPDES) Industrial Stormwater General Permit (ISGP). Services include quarterly sampling, additional sampling, monthly monitoring, semi-monthly monitoring, composing and submitting quarterly reports and annual reports, corrective actions, designing, coordinating and overseeing construction of the advanced treatment system.

    This facility has undergone changes since SoundEarth started providing stormwater consultant support to ensure they stay in compliance with their ISGP. Stormwater was routed to the northeastern side of the facility via pumps and conveyance lines, it passed through an oil/water separator that was installed, to Baker Tanks for stormwater settling and detention before either being used for dewatering or discharging offsite from Outfall A. After installation of the Advanced Treatment System (ATS) in 2017, the Baker Tanks were removed and a chitosan-enhanced sand filtration advanced treatment system was installed on the west side of the shop building. Two Baker Tanks, a 3-pod sand filter, and a control unit allows the stormwater to receive adequate treatment before being discharged from Outfall A. As part of the ATS construction, a trench drain was installed just west of the stormwater vault to intercept any process water discharging form the MERF. Process water is conveyed from the trench drain to an oil/water separator and into a manhole that connects into the City of Seattle sewage system.

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  • Stormwater Treatment System Enhancements Auburn, WA

    Stormwater Treatment System Enhancements

    Auburn, WA

    This industrial facility site is responsible for comprehensive waste handling and environmental services. The site consists of 3.8 acres of impervious surface located adjacent to a local creek which has been identified as an impaired water body several miles downstream and consists of three distinct outfall zones. The site is operating under a Consent Decree as a result of litigation with a third-party citizen group. Heavy metals and turbidity have been consistent challenges for the site to meet benchmarks.

    SoundEarth provided treatment feasibility studies and designed passive treatment solutions that integrated existing site features with low impact development and multimedia technologies. The passive treatment solutions have reduced contaminant loads by over 90 percent to well below benchmark values.

    SoundEarth staff brought an adaptive management approach for informed decision making, and integrated O&M to keep other zones from reaching treatment requirements. Services also included accurate identification of pollution liability. Our records audit revealed an error in regulatory designation that resulted in removing of fecal coliform sampling from required sampling parameters. Our team also provided sampling benchmarks to increase the potential for site compliance. SoundEarth staff performed a Treatment Feasibility Evaluation to enhance pollutant removal.

    SoundEarth services include sampling, integrated O&M plan, compliance reporting, and corrective action adaptive management. We also provided a pollutant source evaluation, and stormwater conveyance mapping and investigation. Treatment system services included feasibility evaluation, an engineering design report, treatment system implementation and ongoing O&M, innovative solutions, and cost benefits to the client. In addition, we provided legal support, records audit, additional zone sampling, and impaired water body investigation.

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