Skip to main content

It Just Goes Away

Buy Article:

$9.50 plus tax (Refund Policy)

Or sign up for a free trial


Duluth is located on the north shore of Lake Superior. It is a community of 86,000 people, it is 26 miles long and 8 miles wide, with changes in elevation in the city from 602 feet to approximately 1300 feet above sea level. Some of this elevation occurs in less than 2 miles. The City of Duluth's Collection System was constructed beginning in 1881 and continued through 1923. In following years the system was added to as the city expanded and is still growing today. The system was built of clay tile pipe, brick arch sewers, wood sewer pipe, and blasted tunnels through bedrock, parts of which were originally a silver mine. Although there are no records on file, some of the employees recall wooden sewers in the early years. The system consists of approximately 420 miles of sanitary sewer main of which only 96 miles is PVC, with over 8,000 manholes. We also operate 260 miles of storm sewers with about 4,950 manholes, 9,400 catch basins and 42 named streams, 10 of which are cold water trout streams. Our weather conditions vary from −35 below zero in the winter to 90ish in the summer. Precipitation averages are about 32 inches of rain and 84 inches of snowfall. This poses some unique challenges in cleaning and maintaining our municipal sanitary sewer collection system. For example:

In the winter we have filled our vactors with hot water from our steam plant to prevent the vehicles from freezing and have found that it also works very well to remove grease from the walls of pipes from our identified “grease lines”

Velocity also has a huge impact on our system. During adverse weather conditions, it carries a tremendous amount of solids that have settled in flat lines which can cause catastrophic pipe failure and related property damage. However on the positive side, velocity aids in scouring of the pipe and the prevention of septic conditions.
No Reference information available - sign in for access.
No Citation information available - sign in for access.
No Supplementary Data.
No Data/Media
No Metrics

Document Type: Research Article

Publication date: 2004-01-01

More about this publication?
  • Proceedings of the Water Environment Federation is an archive of papers published in the proceedings of the annual Water Environment Federation® Technical Exhibition and Conference (WEFTEC® ) and specialty conferences held since the year 2000. These proceedings are not peer reviewed.

    A subscription to the Proceedings of the Water Environment Federation includes access to most papers presented at the annual WEF Technical Exhibition and Conference (WEFTEC) and other conferences held since 2000. Subscription access begins 12 months after the event and is valid for 12 months from month of purchase. A subscription to the Proceedings of the Water Environment Federation is included in Water Environment Federation (WEF) membership.

    WEF Members: Sign in (right panel) with your IngentaConnect user name and password to receive complimentary access. Access begins 12 months after the conference or event
  • Subscribe to this Title
  • Membership Information
  • About WEF Proceedings
  • WEFTEC Conference Information
  • Learn about the many other WEF member benefits and join today
  • Ingenta Connect is not responsible for the content or availability of external websites
  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more