Design and field application of an automated cartridge sampler for VOC concentration and flux measurements

One of the major limitations in advancing the understanding of tropospheric ozone and aerosol generation and developing strategies for their control is the technical ability to accurately measure volatile organic compounds (VOCs). This paper describes the design of a constant flow VOC sampler. The versatile sampler can be used for fully automated concentration and flux measurements of VOCs. The sampler incorporates a microprocessor control unit and provides highly accurate mass flow control and significant ease of operation. Sampling sequences can be programmed directly or by remote control through a PC. All important operational parameters necessary for a complete sampling audit trail are logged. Compact weatherproof housings and low power consumption allow operation at remote sites and locations which are sensitive to disturbances or have restricted access. Inner wetted surfaces of the sampler are constructed from non-contaminating materials that do not sorb or emit VOC, and thus permit the collection of representative samples even in environments with very low VOC concentrations. The cartridge magazine provides a maximum of 20 sequential cartridge samples, which allows for long-term air quality assessments. In the dual channel mode, two samples can be collected simultaneously through two independent sample loops, providing ten sequential sample pairs. This design allows the parallel collection of (a) quality assurance backup samples, (b) samples on two different types of cartridges/sorbents to allow a variety of analyses, or (c) differential samples for flux measurements using enclosure, aerodynamic profile, or relaxed eddy accumulation (REA) methods. Field applications including airplane profile measurements above a tropical rainforest area, as well as gradient and REA measurements over a mid-latitude mixed forest stand are described, and demonstrate the validity and flexibility of the system. In particular, the application of the VOC sampler as an integrated part of a REA system is emphasized.     

Canadian Innovations in Siting Hazardous Waste Management Facilities

/ Siting hazardous waste facilities is an extremely complex and difficult endeavor. Public aversion to the construction of these facilities in or near their community often results in concerted opposition, referred to as the NIMBY syndrome. For the most part, siting processes do not fail because of inadequate environmental or technical considerations, but because of the adversarial decision-making strategies employed by the proponents. Innovative siting processes used in the provinces of Alberta and Manitoba offer tangible evidence of the successful application of an innovative siting approach based on the principles of decentralization of decision-making authority and full and meaningful public involvement. The purpose of this paper is to evaluate four Canadian siting processes from the perspective of public participation and access to decision-making authority. Examples of siting processes related to hazardous waste management facilities are provided from the provinces of Alberta, Manitoba, British Columbia, and Ontario. Siting has evolved from approaches dominated by top-down decision making to increasing decentralized and pluralistic approaches. Focusing on social and political concerns of potentially affected communities and on the process of decision making itself are fundamental to achieving siting success. In Alberta initially, and later in Manitoba, this new "open approach" to siting has resulted in the construction of the first two comprehensive hazardous waste treatment facilities in Canada.KEY WORDS: Hazardous waste facilities; Siting methodologies; Public participation