Hi Dad,
I needed to write a case study for the wastewater chapter of the textbook Mack and I co-author. I had forgotten about it but got a reminder today.
And then when I got the reminder today, I knew that the case study needed to honor you, Mr. Adams, Uncle Walt, and all who made the world a safer and better place.
Love you, Dad.
Tenafly Sewage
Treatment Plant: A Plant Decades Ahead of its Time
It was late 1946 and World War II
had just ended. With the completion of the George Washington Bridge in 1931,
the population of Bergen County, New Jersey had grown significantly. While most of the towns in the county lacked
sewage treatment, Tenafly, a small town of around 7,500 was decades ahead of
its time.
Built at a time when most large
cities treated their wastewater with only sedimentation (primary treatment) and
there were no federal wastewater treatment regulations in the US, the 1.75 million
gallon per day (MGD) plant employed what would be considered today as
state-of-the art treatment. While most
plants used primary sedimentation tanks, this plant used fine screens. From the fine screens, the wastewater flowed
into activated sludge tanks, with air supplied through diffuser plates. The effluent from the secondary clarifiers
was treated through sand filtration and chlorinated prior to discharge. A
portion of the chlorinated plant effluent was recycled into the plant for use
in the chlorinators, which reduced water consumption and costs by up to 75%
(Adams, 1948). The remainder of the wastewater
effluent was discharged to the Tenakill Brook, which flowed 3.5 miles before
discharging into the Oradell Reservoir, the drinking water supply for Tenafly
and the surrounding area.
The raw waste activated sludge was
conditioned with ferric chloride then dewatered using vacuum filtration. It was
then flash-dried, bagged, and marketed as fertilizer. The sludge, “Tenafly Soil Food”, had a
nitrogen and phosphorus contents of 5% and 3%, respectively. It brought a net income of nearly $4000 per
year (Adams, 1948).
So two years before the
promulgation of the Federal Water Pollution Control Act of 1948, the first
major U.S. law to address water pollution, and 26 years before the enactment of
the Clean Water Act (CWA), the Tenafly plant operated as a model for the
nation. It employed innovative technology and equipment, tertiary treatment,
and indirect potable water reuse. It also produced sludge (i.e., biosolids)
that was applied to soil to supply nutrients and replenish soil organic
matter.
Add to references at the end of
chapter:
Adams, J.K. 1948. “Operating Experiences
at Tenafly, NJ”, Sewage Works Journal 20(5): 909-912.
