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Paul V. Rososco, P.E.


Mr. Rosasco has over 40 years of experience in providing supervision, management, and technical review for geological, hydrogeological, and engineering projects largely associated with solid and hazardous waste management. He has designed and implemented geological, hydrogeological and geophysical investigations and environmental monitoring programs for sites ranging from 0.5 acres to over 300 square miles. Mr. Rosasco has extensive project management and technical experience in a wide variety of waste disposal and environmental contamination projects. He has provided design, site engineering, and construction management services and acted as owner’s representative for surface and subsurface remediation projects. He has also been involved in a variety of geotechnical, geologic hazard, and water supply evaluation projects.

Mr. Rosasco has provided expert testimony related to groundwater occurrence, flow and chemical transport, the nature, extent and sources of environmental contamination, the necessity and appropriateness of various remedial actions, consistency of response actions with the National Contingency Plan (NCP) and other environmental regulations, and allocation of response costs. He has also provided expert assistance related to construction claims and disputes. He has provided expert testimony on the role of environmental issues and site remediation related to property valuation and condemnation proceedings. He has testified at numerous regulatory hearings and public meetings on issues ranging from site selection and the design and operations of waste disposal facilities, environmental contamination and remediation, and water quality standards.


M.E., Engineering Geology, Colorado School of Mines, 1985

B.S., Geology, University of Oregon, 1976 

Professional Engineer - Colorado, Washington, Illinois

Former Chairman, Vice-Chairman, and Member - Jefferson County, Colorado Planning Commission, 1994 – 2004

Timothy C. Shangraw, P.E. 


Mr. Shangraw Mr. Shangraw has over 40 years of technical and management experience relevant to hazardous waste site investigations and remediation, water and wastewater treatment, mine dewatering, stormwater planning, and environmental studies. His expertise is particularly strong in managing complex remediation programs from conceptual design through detailed design, construction, and operations.


For the past 35 years, Mr. Shangraw has managed remedial design, remedial action, and O&M of the Lowry Landfill Superfund Site near Denver, Colorado. This has been a $100M+ project involving groundwater cutoff walls, pump and treatment systems, capping, waste pit remediation, landfill gas collection and treatment, and extensive environmental monitoring. Unique challenges included development and application of emerging technologies to oxidize and biodegrade 1,4-dioxane and other organic compounds and to sequester inorganic compounds. Such technologies involved both in-situ and above-ground treatment methods. Case studies were published in technical journals and/or presented to national technology-transfer organizations.


Throughout his career, Mr. Shangraw has managed and technically directed regulatory closures for Superfund, RCRA, TOSCA, and radioactive mixed-waste sites for Fortune 500 companies throughout the United States, for DOD sites, and for US DOE sites. He has also assisted clients with estimating present and future environmental liabilities for current assets and pending acquisitions and divestitures.


M.S., Civil/Environmental Engineering, University of Colorado, 1979

B.S., Civil Engineering, University of Massachusetts, 1977

Professional Engineer - Colorado

Board of Directors, Willowbrook Water and Sanitation District, 2008 - current