Details and Metadata

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Methods

The methods followed in the creation of the dataset, including description of field, laboratory and processing steps, and quality control procedures

Current Methods

  • Sampling HAPs
    Started: 1993-01-01

    Currently, the VT AQCD measures ambient concentrations down to parts per trillion by volume (pptv) and nanogram/M3 (depending on the particular method) of 96 separate HAPs. These include volatile organic compounds (VOC) such as benzene, 1,3 butadiene; carbonyl compounds such as formaldehyde, acetaldehyde; metal compounds such as arsenic, lead; and polycyclic aromatic hydrocarbons (PAH) such naphthalene, benzo-a-pyrene. (For the complete list of Air Toxics) The VOC samples are collected using 6-liter Silco-treated stainless steel canisters which are analyzed at the VT DEC/AG lab by gas chromatography/mass spectrometry (GC/MS). The carbonyl samples are collected using a special cartridge which contains silca gel coated with dinitrophenylhydrazine (DNPH) which is extracted at the VT DEC/AG lab and analyzed by high performance liquid chromatography (HPLC). The metals samples are collected on 47 mm Teflon filters which are extracted at the VT DEC/AG lab and analyzed by inductively coupled plasma/mass spectrometry (ICP/MS). The PAH samples are collected on a 104mm quartz fiber filter combined with a polyurethane foam plug (PUF) containing XAD resin both of which are extracted at an EPA contract lab and analyzed by GC/MS.

    Instrumentation: 6-liter Silco-treated stainless steel canisters andgas chromatographs/mass spectrometers; other specialized spectrometers

Dataset Fields

Detailed documentation of the fields comprising the dataset, including the type of measurement, units where applicable, and any controlled vocabularies or code lists present in the data


No documentation available for these fields

Sampling Equipment

Equipment and software used to collect data, including how that equipment was used.

Current Equipment

  • HAP sampling
    Started: 1993-01-01

    The permanent monitoring sites are located in Burlington, Rutland and Underhill. VOC and carbonyl samples at the Rutland and Burlington urban sites are collected every 12 days on a US EPA schedule. The Burlington site has separate collocated samplers to provide method quality assurance. At the Underhill rural site, VOC, carbonyl, metals and PAH samples are collected every 6 days on a US EPA schedule. Since 2004, the Underhill site has participated in US EPA’s National Air Toxics Trends Stations (NATTS) network designated as a rural background site.

    Frequency: Burlington and Rutland every 1 in12 days; Underhill every 1 in 6 days

Site Characteristics

The spatial extent of the dataset site coverage, and descriptions of the spatial extent and context for the data collection

  • Site Description

    Burlington South Winooski Avenue: This site is located in a municipal parking lot of downtown Burlington, VT, located 1 km east of Lake Champlain, 1.5 km south west of McNeil Generating Station, 2 km west of I-89, and 8 km west of the Essex IBM plant. This site is designated to represent middle and neighborhood-scale. The monitoring location meets all siting requirements and criteria and has been approved by VTAQCD and EPA Region 1.

    Minimum Altitude: 62 meters

    Maximum Altitude: 63.1 meters

  • Site Description

    Underhill at Proctor Maple Research Center: This site is located at the western slope of Mount Mansfield at the north end Underhill, VT. The site is rural in nature and located 5 km south west of the summit of Mount Mansfield, 6 km south of Route 15, and 26 km east of Burlington. This monitoring location meets all siting requirements and criteria and has been approved by VTAQCD and EPA Region 1

    Minimum Altitude: 391 meters

    Maximum Altitude: 392 meters

  • Site Description

    Rutland: This site is located in a court house parking lot in the downtown area of Rutland, 1 km from north junction of Route 7 & Route 4, 3.5 km from south junction of Route 7 & Route 4, 4 km NW of GE plant. The site is adjacent to a postal center distribution center which serves as the parking area for USPS vehicles. This monitoring location meets all siting requirements and criteria and has been approved by VTAQCD and EPA Region 1.

    Minimum Altitude: 164 meters

    Maximum Altitude: 165 meters