Begun as a research project in 1962, the Penn State Waste Water Renovation and Conservation project demonstrated that treated effluent could be successfully recycled back into the water supply when applied to agricultural land under the right conditions. Today, the university pumps hundreds of millions of gallons of waste water each year to land north of the university where, instead of being discharged into streams, it is sprayed on agricultural and forest land, and eventually replenishes local groundwater supplies.

Pennsylvania State University, Department of Public Information
The Living Filter
circa 1972
From the Penn State University Archives

CO2 PPM in 1972: 326