CVEN 5534: Wastewater Treatment

Assignment 1: Due Tuesday, 1/20

BACKGROUND

In 1905, Pennsylvania passed a law forbidding the discharge of untreated sewage from

new sewerage extensions and extensions of existing sewerage systems into streams. The law was

administered by the State Board of Health, staffed mostly by physicians.

In 1910, Dr. Samual Dixon, the Pennsylvania Commissioner of Health, required

Pittsburgh to submit a comprehensive plan for replacing the city’s combined sewer system [both

sewage and stormwater] with a separate sanitary sewer system and treatment plant. This plan

was a condition for receiving a temporary discharge permit. The city hired two well-known

sanitary engineers, Allen Hazen and George Whipple, to make recommendations. After a year of

investigation, Hazen and Whipple made what the Engineering Record called: “The most

important sewerage and sewage disposal report made in the United States.”

Hazen and Whipple estimated that replacing Pittsburgh’s combined sewers with a

separate system and building a treatment plant would cost Pittsburgh taxpayers a minimum of

$46 million [in 1912 dollars!], not including any costs for disruption of city activities during

construction. At the same time, they calculated that if Pittsburgh did not replace the combined

sewers and treat the wastewater, the 26 towns located downstream from Pittsburgh on the Ohio

River, who did not treat their drinking water, could then provide filtered water for their residents

for a far lower cost. Hazen and Whipple argued that no precedent existed “for a city’s replacing

the combined system by a separate system for the purpose of protecting water supplies of other

cities.” They concluded in their recommendation to the City that “no radical change in the

method of sewerage or of sewage disposal as now practiced by the City of Pittsburgh is

necessary or desirable.”

Engineering opinion at the time overwhelmingly support the Hazen and Whipple report

and viewed the controversy as an issue as to “how far engineers are at liverty to exercise their

own judgment as to what is best for their clients and how far they must give way to their medical

colleagues.”

Uncertain of his ability to compel Pittsburgh to build a separate system and treat its

sewage, Dixon retreated and issued the city a temporary discharge permit without the plan. The

State Commissioner of Health continued to issue such permits to the city until 1939.

ASSIGNMENT:

Suppose it is 1910 and you have just read the Hazen and Whipple report, but you had the level of

technical and environmental knowledge we have today. Write a letter to the editor of the

Engineering Record expressing your views. Include in this letter considerations that were

apparently not taken into account by Hazen and Whipple and discuss how they might result in a

different recommendation. AT A MINIMUM, these should include: costs and benefits, the

definition of “client,” environmental ethics, multiple use of resources, concept of use of tax

money to build treatment plants to benefit non-taxpayers.

Length: 3 – 5 typed pages, double spaced.