As Vietnam War protesters increased in number and voice, the first Earth Day was celebrated, the Clean Air Act was passed by Congress, the U.S. Environmental Protection Agency (EPA) was formed, and a decade of environmental conservancy began.

A milestone for the environmental movement was set in 1971 when the EPA established national health-based air quality standards for pollutants in the ambient air.

	The first Earth Day was held on April 22, 1970. It was commemorated by a photograph of the earth taken during the Apollo 13 moon landing, and kicked off a decade of environmental awareness and action.

In this period, the Air District added three counties to its jurisdiction--Napa, southern Sonoma, and western Solano counties--bringing the district to its current total of nine counties.

The California Air Resources Board adopted strict automobile emissions standards, and the Air District adopted hydrogen sulfide controls on industry. Burning at dumps was banned throughout the state of California, and the Air District adopted an ambient lead regulation. And, for the first time, the Board of Directors prohibited smoking in the board chambers during meetings.

The Air District's permit system was adopted in 1972, as was a landmark odor regulation--the first of its kind in the nation. The District's "smog phone" for air quality readings began in May of 1972 and a carpool lane was opened on the Bay Bridge. Computer carpool matching also became available.

The Air District's big story of 1973 was the adoption of its vapor recovery regulation, which would reduce hydrocarbon emissions at gasoline stations by 70 tons per day--the largest emission reduction generated by any regulation thus far.

Air District employees demonstrate the portable olfactometer that was used for research in developing the odor regulation, and later for determining compliance.

Unleaded gasoline became available in July of 1974. In addition, an Air District Air Pollution Episode Plan was adopted with a "smog advisory" level set at 0.20 parts per million (ppm) of ozone. (Unfortunately, the 1974 summer smog season logged the longest consecutive run of smog advisories--three days in October when the maximum ozone concentration reached 0.28 ppm.)

The early '70s showed that air pollution control was firmly entrenched in the national agenda and would continue to be in the "environmental decade" and beyond.

1970

The Air District bans backyard burning in the Bay Area.

The Clean Air Act is passed by the U.S. Congress and signed by President Nixon.

The U.S. Environmental Protection Agency (EPA) is created.

1971

EPA establishes National Ambient Air Quality Standards (NAAQS) for particulates, ozone, carbon monoxide, nitrogen dioxide, and sulfur dioxide.

The Air District adopts emission standards for lead.

Napa, Solano, and Sonoma counties become active members of the Air District.

The Air District makes the first major revision to Regulation 2, tightening emission standards for particulates and sulfur dioxide.

ARB adopts the first nitrogen oxides emission standard for automobiles in the nation.

1972

The Air District adopts the first non-specific odor regulation in the nation.

The Air District's permit system is approved by the Board of Directors.

The Air District adopts a three-stage episode plan for high air pollution days.

The "smog phone" for air quality readings is introduced.

A carpool lane is provided on the Bay Bridge.

1973

The California legislature authorizes the Air District to seek civil and criminal penalties for violations of any rule or regulation.

1974

The first gasoline vapor recovery program in California is adopted by the Air DistrictÕs Board of Directors.

1975

The first integrated regional air quality ozone model in the nation is completed by the Air District, in conjunction with Lawrence Livermore Laboratories and NASA-Ames Research Center.

Bay Area emission limits on nitrogen oxides take effect.

The Air District begins use of a new radio communications system, involving two transmitters and a computer linkup, accelerating the dispatch of air pollution complaints to inspectors in the field for investigation.