A History of the Firm

The ability to deliver effective design solutions for complex environmental engineering challenges has been the hallmark of Greeley and Hansen's long and succesful history. The firm combines technical knowledge, proven insight, and creativity to provide municipal utilities and agencies with innovative and practical engineering, architectural, and management solutions that result in better urban environments.

Greeley and Hansen's search for challenging assignments began 100 years ago, in 1914, a time when the water and wastewater industry was in its formative years. In those days, sewage was referred to as "wishwater" in polite company.

The driving force of the founding of Greeley and Hansen was Samuel A. Greeley. Born on Chicago's north shore in 1882, Greeley was educated at Harvard and MIT. His first professional position was with an engineering firm headed by Rudolph Hering. Greeley soon became Hering's principal assistant, and together they focused their attention on refuse disposal projects. As their expertise built, it provided the foundation for the industry's first comprehensive study on solid waste collection and disposal. Published in 1921, the co-authored classic The Collection and Disposal of Municipal Refuse served as a standard textbook for decades.

In 1912, Greeley accepted a new job from the Sanitary District of Chicago. As assistant to Langdon Pearse, already a well-respected engineer, Greeley developed first-hand experience with one of the county's foremost experts in sewer system design.

Recognizing the great nationwide need for their talents, in 1914 the two founded their own practice--Pearse and Greeley. The Sanitary District of Chicago continued to trust in those two men and became the firm's first client.

By 1920, Paul Hansen, another MIT graduate, joined the firm as a full partner. His previous accomplishments included services as chief sanitary engineer for the Illinois State Department of Public Health. The partnership was renamed Pearse, Greeley and Hansen, providing a full range of environmental engineering services for water supply and purification, and sewage and refuse disposal.

When Pearse left the partnership in 1932 to concentrate full-time on his continuous responsibilities with the Chicago Sanitary District, the firm became Greeley and Hansen. Later, after the deaths of Hansen in 1944 and Greeley in 1968, the remaining partners chose to retain the firm's name-a posthumous tribute to the gentlemen's expertise and leadership in providing a solid foundation upon which the firm continues to grow.

A firm with more than nine decades of continuous service has milestones along the way that enhance the course of their journey. These milestones are highlighted below:

1920's
Greeley and Hansen at the forefront of a new technology that combined clarification and sludge digestion in one tank.

1930's
Greeley appointed to prestigious Washington DC Board of Engineers, established in 1935 to implement solutions to pollution caused by raw sewage disposal in the Potomac River.

1940's
Designed a massive water supply project for Toledo, Ohio which was dubbed" the greatest single public improvement in the history of Toledo" by the Toledo Citizens Waterworks Dedication Committee.

1950's
Richard Gould, a renowned leader in wastewater treatment, became a special advisor to Greeley and Hansen, and pioneered step aeration, a technique of modifying the activated sludge process.

1960's
At New York City's request, Greeley and Hansen designed the 2,500-mgd Spring Creek CSO treatment facility, one of the country's first CSO treatment facilities.

1970's
Design and construction of the 60-mgd Hooker's Point denitrification facility in Tampa, one of the world's first full-scale installations to use pure oxygen for nitrification.

1980's
Developed a master plan for wastewater treatment and nutrient control for the Upper Potomac Basin, providing environmental protection for more than two million people in the Washington DC area.

1990's
Opened multiple offices across the country. Established the Utilities Management Consulting arm of Greeley and Hansen.

2000's
Focusing on the future, the firm revitalizes its brand and logo. Re-branding reinforces Greeley and Hansen’s continuing commitment to provide clients with innovative solutions that combine creativity with precision engineering to help them create better urban environments.

2010’s
Greeley and Hansen marks its 100th anniversary year (2014)! The firm builds its global footprint by expanding business operations in targeted high-growth international markets.