Clean Air Act of 1970

Transcription

1 Clean Air Act of 1970 Set National Ambient Air Quality Standards (NAAQS), to protect public health and welfare Set New Source Performance Standards (NSPS), that strictly regulated emissions of a new source entering an area. Pre-1970 polluters are still regulated differently today. Standards were also set for hazardous emissions and emissions from motor vehicles Categories of Air Pollutants Primary Pollutants Primary Pollutants (by weight) Hydrocarbons Secondary Pollutants Criteria Pollutants Requlated by the CAA; can be primary or secondary. Levels need to be below NAAQS 1

2 Sources of Primary Pollutants Carbon monoxide (CO): CO is a colorless, odorless, and poisonous gas produced by the incomplete burning of coal, wood, and oil. More than three-quarters of U.S. emissions are from motor vehicles and nonroad equipment. Sulfur dioxide (SO 2 ) SO 2 is a colorless gas originating from the combustion of sulfur-containing fuel, such as coal and oil. Important sources are power plants, smelters, pulp and paper mills, and petroleum refineries. SO 2 is also a cause of acid rain. Nitrogen oxide (No x ) Nitrogen oxides are gases that form during the high-temperature combustion of fuel when nitrogen in the air or fuel reacts with oxygen. Motor vehicles and power plants are the primary sources. It is also a contributor to acid rain. Volatile organic compounds (VOCs): VOCs are also called hydrocarbons. They encompass a wide array of solids, liquids, and gases. Particulate Matter: These pollutants consist of particulate matter, which is a mixture of solid particles and liquid droplets found in the air. Fine particles are less than 2.5 micrometers in diameter These are from combustion, wood burning, and power generation. Coarse particles are less than 10 micrometers. These particles come from dirt roads and crushing and grinding operations. 2

3 Secondary Pollutants Acid Rain Smog Gray air cities (NE): cold, wet climates SOx and PM from coal/oil burning produced smoke & fog: Industrial Smog Brown air cities: warm,dry,sunny climates Triggered by sunlight, VOC and NOx are involved in a series of reactions producing many harmful pollutants: Photochemical Smog Included in photochemical smog is over 100 chemicals including formaldehyde, ozone and several acids Photochemical Smog Morning traffic produces all the ingredients needed Concentrations peak in the afternoon with increased sunlight Drifts many miles downwind Ozone: Irritates lungs & eyes Reduces crop yields/forest growth Damages rubber, plastic, paint Criteria Pollutants CO, PM, SO 2, NO 2 + Lead + Ozone (which indicates smog) Phase out of leaded gasoline has eliminated lead pollution NAAQS highest level that can be tolerated by humans without ill effects Emissions Trends ENVI 420 ENVI 420 3

4 U.S. Pop. Living above NAAQS ENVI 420 Air Quality Index Air Quality Index (AQI): The AQI is an indicator for reporting daily air quality to the general public. The EPA calculates the AQI for five pollutants regulated by the Clean Air Act (O 3, PM, CO, SOx, NOx). The AQI scale runs from Less than 100 on the scale is good. Greater than 100 is considered unhealthy. Sulfuric acid & Nitric acid are 2 of the 3 strongest acids known Dry deposition ~ 50% of fallout 4

5 PH of Rain (2011) Effects Acidification of fresh water ecosystems Adirondack region - 25% of lakes too acidic to support life. 80% of lakes with ph < 5 were lifeless Eastern U.S. - 8% of streams, 4% of lakes are too acidic to support life Effects diversity Al (toxic to freshwater fish) is leached from the soil by the acidic water Devoid of fish: Scandinavia - 16,000 lakes Canada - 14,000 lakes United States - 9,000 lakes Effects - Vegetation Reduces crop yields Harms foliage Damages roots Dissolves nutrients & minerals from the soil slowing growth Mt. Mitchell, NC Effects -Materials Corrodes Metals Damages/erodes automotive paint Erodes stone such as marble & limestone CAA Amendments of 1990 Acid Rain Program Set emission standards for 190 toxic chemicals Established a system of pollution taxes on chemical emissions Tightened emission standards on cars/trucks Cap and Trade of emissions 5

6 Cap national limit on amount of pollutant that can be emitted Trade Allowances for emissions are traded (sold) between sources SOx Regulations Reduce annual SOx emissions by 10 million tons below 1980 levels by 2010 Phase I (110 coal burning plants) Began in 1995 and reduced SOx emissions by almost 40% below required level Phase II (all electric utilities) Began in 2000 Established emissions trading of SOx, credits (Cap and Trade). Companies with low emissions can sell their credits for profit. Total Annual SO 2 Emissions From Acid Rain Sources ( ) Phase II new cap Emissions cut by 2/3 since 1980 NOx Regulations NOx is more difficult to reduce, initially called for 10% cut reductionemissions reduced by 2/3 since 9995 Summary 1990 CAA Amendments called for a 50% reduction in SOx and 10% reduction in NOx Reducing sulfur emissions was successful. It occurred quickly and at less cost to industry than predicted. Most SOx emissions are from stationary plants. Emissions of nitrogen oxides and nitrate concentrations in rain have decreased slowly. One half of NOx emissions are from vehicles. New England lakes have shown slight recovery; Adirondacks have not 6