1905 Purity Water Act passed by State Legislature to address abatement of untreated sewage discharges throughout the state. No one complied.

1945 Pennsylvania Municipality Authorities Act created.

1946 State Sanitary Board ordered 102 municipalities and 90 industries to quit discharging untreated sewage into area waterways.

March 13,1946 Allegheny County Sanitary Authority formed through incorporation. Authority created for the purpose of providing sewage collection and treatment on a county-wide basis to meet the requirements of the Pure Streams Act of 1937 which dictated pollution abatement of streams and rivers.

March 15,1946 First meeting of the Authority Board of Directors. Retired Col. John F. Laboon, P.E., Authority Executive Director and Chief Engineer, was elected chairman. The Board consisted of five members appointed by the county.

1947 In-house laboratory established.

December 21,1947 ALCOSAN laboratory selected as one of the six outstanding sewage research labs established in the country.

January 1948 A comprehensive report completed recommending a county-wide sewage plan which was rejected by rural municipalities. Later, under the leadership of the City of Pittsburgh, a project was adopted to include the city and 67 surrounding municipalities.

August 22,1948 Resolution accepting Authority service adopted by Pittsburgh City Council.

1955 The Authority Board reorganized with the City appointing three board members and the County of Allegheny two members.

October 1955 The City of Pittsburgh presented an agreement for the sale to the Authority of 16.85 acres plus 20 building lots, formerly Verner Town, for $250,000 for the plant site.

1956 A loan from 23 banks totalling $100 million received to construct treatment plant, intercepting sewers and related systems.

January 12,1956 First contracts awarded to 20 contractors for 23 separate contracts. The cost of the plant except for chimney-$16,690,765.

April 1,1956 Groundbreaking ceremony to build plant.

January 22,1959 Sewage rate of $0.30 per 1,000 gallons charged.

April 30,1959 Treatment plant placed into operation.

October 1,1959 Formal dedication of plant culminating six years of preparatory work, four years of design and three years of construction. There were 11 strikes and two fatalities during construction. When the plant was dedicated, 70 municipalities and 27 industries had executed service area agreements with ALCOSAN.

March 1960 The American Society of Civil Engineers awarded ALCOSAN an honorable mention as the second outstanding civil engineering project of the year. This was the first time the ASCE committee made an exception in its policy to award an honorable mention.

1966 Billing Office Building constructed.

March 1966 The Pennsylvania Sanitary Water Board issued an order requiring the Authority to provide a higher degree of treatment. This resulted not from any criticism of the plant, which was commended, but from the nationwide trend toward higher river-quality standards.

1970 Construction began of $45 million in plant additions to provide additional sludge disposal facilities and secondary treatment.

1972 Construction of Sludge Dewatering Building completed.

October 1973 Secondary treatment facilities begin operation.

1978 Triaxle trucks received for hauling sludge as a supplement to incineration.

1980 An experimental land application project instituted utilizing liquid sludge as a fertilizer for sod production. Results showed that time to produce mature sod was cut in half.

Summer 1980 Experimental garden established with the planting of vegetables and 10,000 flowers to evaluate sewage sludge as a fertilizer for crop production. Analysis proved no harmful metals uptake in the vegetables.

July 1981 Limed sewage sludge applied to 60 acres of stripped mined area for the first time.

1984 Pretreatment Program put into effect.

1988 The Board reorganized with the City and the County each appointing three members with a seventh seat designated as a joint City-County appointment.

September 1990 Ribbon cutting ceremony of carbon scrubbers at dewatering facility.

November 1990 ALCOSAN mascot "Frankie the Fish" created; stars in public service announcement on television about pollution prevention.

1991 Dewatered, limed sludge used for land application program coined ALCOSOIL.

1993 New laboratory facility begins operations.

January 1994 ALCOSAN begins planning process for plant expansion to meet the needs of the next millennium.

December 1994 New fluidized bed incinerators begins operation.