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Item No: 7F Meeting Date: November 28, 2011 Type of Business: Council Business Administrator Review: ____ City of Mounds View Staff Report To: Honorable Mayor and City Council From: Nick DeBar, Public Works Director Item Title/Subject: Resolution 7861, Authorizing Stork Twin City Testing Corporation to Perform a Preliminary Geotechnical and Environmental Evaluation for Area E of the Street and Utility Improvement Program Background/Discussion: The City Council authorized Stantec (formerly Bonestroo) to perform engineering services for the design phase of Area E of the Streets and Utilities Improvement Program on September 26, 2011 (Res. 7831). A geotechnical and environmental evaluation of subsurface conditions is customarily performed for any project with land disturbing activities. This evaluation will provide recommendations to be incorporated into the engineering design of pavements, utilities, and infiltration basins. Three qualified geotechnical firms were solicited to provide the following services: • 10 borings in the street (6’ depth) to determine existing typical section; • 3 borings in the street (15’ depth) to determine soil conditions for sanitary sewer replacement; • 11 boulevard soil borings (6’ depth) to determine suitability for infiltration feature; • 1 boulevard boring (15’ depth) to determine soil conditions for sanitary sewer replacement and suitability for infiltration feature; • Gradation test per each (qty 2-3). Gradations will be required for the boulevard borings if an SM soil is encountered below 30” from the surface; • Engineering report with recommended R-value for Sunnyside Road, which is a designated Municipal State Aid roadway; and • Test material in the top portion of the road borings only for Diesel Range Organics (DRO), including: Costs for an environmental technician to be on Site during the borings in the street to monitor the materials in the upper 2 feet at each location. Documentation of soil discoloration and odors if detected. Obtain one soil sample from each street boring in the upper 6” to 12” range and the upper 18” to 24” range (i.e. two samples per boring) for chemical analysis. Analyze samples in upper 6” to 12” range for DROs. If DROs are present at a given location, and after notifying the City/Bonestroo, analyze the sample for the same location that was taken from the 18” to 24” range. Provide these costs on a per each basis, as the number of tests will be dependent on what is found in the upper sample. Analyze two of the samples collected from the street borings for PCBs, VOCs, and the 8 RCRA metals in anticipation of possible offsite disposal. Staff received two proposals for the geotechnical work: Stork Twin City Testing Corporation for $5,882 and Braun Intertec Corporation for $10,686. Recommendation: Staff recommends that the City Council consider adopting the attached Resolution authorizing Stork to perform a preliminary geotechnical and environmental evaluation for the Area E project. Staff further recommends a 10% contingency ($618) be added to Stork’s fee if field conditions warrant additional investigation, for a budget amount not to exceed $6,500. Any additional work associated with this contingency will be pre-approved by the Public Works Director. If adopted, Stork is expected to begin work immediately. Respectfully submitted, Nick DeBar - Public Works Director