Virgin Islands Air Pollutant Emission Inventory [Draft]

Hoffman, Alan

This report summarizes the Virgin Islands area air pollutant emission inventory conducted in January 1970. The data and emission estimates presented are for 1968 and indicate the conditions during that year. The Study Area is based on population distribution and air pollutant sources. It comprises the three major islands in the grouping, namely St. Thomas, St. Croix, and St. John. This area covers approximately 137 square miles and had a 1968 population of 60,400. A grid coordinate system was used to show the geographical distribution of emissions within islands. The Study Area was subdivided into 31 grid zones of 25 square kilometers. All sources of emissions were classified into five categories-transportation, stationary fuel combustion, solid-waste disposal, industrial processes and evaporative losses. Each of these source categories was divided into two subgroups--point sources and area sources. Facilities emitting large quantities of air pollutants were considered point sources. The many remaining contributors such as motor vehicles, residential fuel users, small commercial and industrial facilities and on-site refuse burning equipment, were considered collectively as area sources. For this report individual sources having emissions greater than zero tons per average annual day for any pollutant were classified as point sources. Emissions were estimated by using various indicators such as fuel consumption, refuse burning rates, vehicle miles, production data, and control efficiencies and emission factors relating these indicators to emission rates. 2 These factors represent average emission rates for a particular source category. Since individual sources have inherent differences that cannot always be taken into consideration, discrepancies between the actual and estimated emissions are more likely in individual sources than in the total emissions for a source category. As in all emission surveys, the data presented are estimates and should not be interpreted as absolute values. The estimates are, in some cases, partial totals due to the lack of emission factors and production or consumption data. Despite these limitations, the estimates are of sufficient accuracy and validity in defining the extent and distribution of air pollutant emissions within the Study Area.