LEI evaluated existing site drainage conditions and then designed a stormwater drainage system that provides the required water treatment, detention and conveyance for the entire site. The site is a 4.86 acre commercial development in the City of Tualatin consisting of five structures, parking lots, pedestrian facilities and landscaping. The City of Tualatin Stormwater Master Plan requirements were followed. This included allowing 0.9 cfs of runoff for 25-storm event, while providing detention for the remainder of the runoff. Water Quality flows had to be treated before entering the public stormwater system. The entire stormwater system for the site provided conveyance for at a minimum, the 25-year storm event.
LEI also provided erosion control and sedimentation control plans for permitting. A Stormwater Drainage Report was provided, which consisted of runoff calculations, pipe sizing calculations, conceptual drawings and design drawings. Erosion control and sedimentation control plans were developed for the 1200C DEQ permit. Grading design, sanitary sewer design and waterline design were completed and building permits approved for construction. This project was in coordination with the client involved the City of Tualatin, Oregon Department of Tranportation, Washington County and Cleanwater Services.
LEI currently holds a five-year, $5 million, A/E IDIQ contract with the USDI Bureau of Land Management that is administered out of Portland, Oregon. LEI is the team lead for a five-firm multi-disciplinary team to complete a wide range of A/E projects that include architectural, design, land survey, condition assessment, construction administration and NEPA. A selection of task orders assigned LEI are as follows:
Coleman Creek Bridge Design: LEI completed the survey, design, and preliminary construction administration for the replacement design of a 12-foot dia culvert with a 60-foot span concrete bridge: Topographic survey, hydraulic analysis, structural design, civil design, construction document preparation, schedule of items and engineers estimate.
Bear Camp Road(Galice) EFRO Slide Repairs: LEI completed the survey, design, and construction administration of nine segments of the Bear Camp Forest Highway damaged by landslides. Funding for slide damage was through Western Federal Lands Highway Department EFRO funds: Topographic survey, geotechnical investigation and analysis, civil design, construction documents, engineers estimate, schedule of items and specifications.
Molalla/Quartzville Road Hazard Assessment: LEI completed road hazard assessment on two forest highways approximately 40 miles in length: Centerline traverse survey, assessment of clear zone violations, determination of need for guard rails, design speed analysis and assessment of other safety features designated by AASTHO.
LEI also completed Marmot Dam existing bridge load rating and site condition assessment: Conditions assessment of the Marmot Dam recreation site for future development, load rating and re-decking assessment of large steel pedestrian bridge, analysis of existing shotcrete wall, topographic survey of planned new recreation site, preliminary assessment of vehicle traffic patterns and parking.
LEI evaluated existing site drainage conditions and then designed a stormwater drainage system that provides the existing water treatment and conveyance for the entire site for the Oregon Department of Transportation Right-of-Way. The site is a 2.83 acre commercial development in the City of Springfield consisting of a hotel, parking lot, pedestrian facilities and landscaping.
LEI followed the City of Springfield Engineering Design Standards. The City of Portland Stormwater Management Manual (BES) governed water quality standards. Moreover, the water quality demand flows had to be treated before entering the public stormwater facilities. This required LEI to use both vegetated swales and water quality catch basins. The entire stormwater system for the site provided conveyance for at a minimum, the 25-year storm event.
LEI also developed erosion and sedimentation control plans for the project site. We also provided a stormwater drainage report, which consisted of runoff calculations, pipe sizing calculations, conceptual drawings and design drawings. LEI developed erosion control and sedimentation control plans for the 1200C DEQ permit. In addition, we completed grading design, sanitary sewer design and waterline design along with approved building permits for construction.
LEI was the lead civil design and land survey consultant for the master planning and initial design for development of an approximate 270 acre tract at the former Fairview Training Facility (Oregon State Mental Hospital). Initial development included remediation of approximately 40 acres of soils contaminated by pesticides from a previous orchard. This remediation involved removal of approximately 125,000 cubic yards of contaminated soils and placement in a permanent onsite storage cell.
Civil Engineering and Land Surveying
Working collaborately with the project environmental sciences consultant, LEI developed an excavation design for the removal of all contaminated soils within the project site. This excavation involved removal of the upper 8”-24” of contaminated soil over a 40 acre area. In addition, LEI developed an onsite storage cell design design for storage of contaminated soils, which involved expansion of an existing weathered basalt rock pit. This expansion included the excavation of approximately 100,000 cubic yards of weathered basalt from the pit. From the onset of the soil remediation effort and to this day, LEI has developed ongoing extensive erosion control plans for the site. These designs included ongoing monitoring and the use of erosion control features from sediment fences to settlement ponds. LEI developed a comprehensive Storm Water Mangement Plan for the project site during the Master Planning Phase of work. During the soil remediation effort, LEI worked to deploy several innovative stormwater treatement solutions, in addition to traditional solutions, to meet the unique characteristics of the project site.
LEI also provided value engineering, development of construction costs (engineers estimate), review of requests for information (RFI’s), submittals, change order requests, construction inspection/observation, photo journaling of construction progress and collaboration with regulatory agencies.