Phase I of Langdon’s Utility Improvement Project was recently named 2019 Project of the Year by the North Dakota chapter of the American Public Works Association (APWA).
Criteria used in the selection process included the demonstration of good construction management techniques, safety, community relations, environmental protection, unusual accomplishments, and commitment to sustainability. The Langdon Project won the honor in the categories of ‘environment’ and ‘communities serving less than 5,000 people’.
The City had recently abandoned its water treatment facility in favor of a more reliable water source connection with the Northeast Regional Water District. This change helped the City divert some funds that were being used for treating water to other infrastructure needs. The City of Langdon worked with Moore Engineering to begin the multi-phase, multi-year process of updating their existing, aging infrastructure throughout the City. This process started by reviewing all of the records that the City had on their existing system, including reviewing the age of the existing sanitary sewer mains, water mains, storm sewer, lift stations, water towers, streets, and all other items relating to their infrastructure.
Sanitary Sewer Main
To better understand the project scope, the City hired Johnson Jet-Line to clean and televise 70,000 linear feet of their sanitary sewer mains over a span of several months. Numerous issues were found upon inspection, which helped the City better understand their sewer mains and gave Moore Engineering a better idea of the most critical areas to be replaced in the first phase of the project. The City decided to replace the main sanitary sewer trunk line out of the main lift station running north and then east, reaching toward the east side of the City. This allowed them to address a large amount of the sewer issues. During the design process, Moore Engineering realized that if the project lowered the sanitary sewer main at the main lift station, that a lift station on 5th Street north of 12th Avenue could be eliminated in a future phase of the project, in turn, saving the City costs in pumps, electricity and overall maintenance. Lowering of the sanitary sewer would also help the City address the shallow sanitary sewer mains, which were only 4 to 5 feet deep in some places, reducing the risk of freeze-up.
The water main was installed with a minimum of 9.5 feet of cover to help prevent freezing. The storm sewer mains and structures were also replaced with updated structures and pipe. By replacing the storm sewer, the project replaced a portion of the main drain within the City, which collects a large amount of the storm sewer runoff from the north side of the City and directs it through the City into the Langdon reservoir on the south side. This storm sewer used to run parallel to the elementary school, cutting off potential expansion of the school. The storm sewer drain was moved into 7th Street and positioned for future connection so that the utility was out of the private property. The second phase of the project will connect this storm sewer with the open drain between 7th Street and 8th Street to convey the storm sewer to the south.
Wastewater Treatment Ponds
The City was also having issues with their wastewater treatment ponds, which had inadequate storage and were unable to transfer wastewater between the ponds efficiently. As part of the project, a small sanitary sewer transfer station was installed between the ponds to allow for a more efficient transfer of the sanitary sewer, if needed. This transfer station will allow the City to move wastewater during times of discharge instead of relying on gravity to transfer the sanitary sewer, which was not possible with the existing layout and elevations of the treatment ponds. In addition, the project included raising the treatment ponds’ levees to allow for additional storage. The project also included replacing rip rap on the pond levees to protect the levees from future erosion. The existing rip rap was a combination of rock and concrete chunks that had accumulated on site over time from other projects. This rip rap was not protecting the levees of the treatment ponds from erosion and wave action.
After all the utility work was completed on the project, the City also addressed the degrading streets that were in need of replacement. The City repaired multiple sections of curb and gutter, valley gutters and other drainage areas, as well as a full replacement of the streets in the project areas. The City chose to utilize existing funds on hand to install a concrete street section along 7th Street in lieu of replacing it with asphalt. This street section of 7th Street from 9th Avenue to 12th Avenue is a major thoroughfare to the high school, city park, outdoor pool, elementary school and baseball fields located in the center of Langdon. Due to the amount of activity and traffic along this street, the City chose to invest additional funds in this street section.
At the end of the project, the City had a portion of its water mains, sanitary sewer mains, storm sewer, wastewater treatment ponds and street systems improved. This included deeper sanitary sewer to remove a lift station on the next phase of improvements, deeper water main to prevent future freezing issues, a tracer wire locating system and locater to help locate the installed utilities and an improved drainage system to help convey the stormwater runoff from the streets into the storm sewer system, with the hopes of extending the life of the streets with less standing water on them. The wastewater treatment system is now much more user-friendly and will cut down on the time of transferring wastewater from one pond to the next. This project is the beginning of a multi-phase improvement plan for the City to address all of their infrastructure needs, but it is a big step in improving the utilities and street system in the City of Langdon.
This first phase of the project was started in Septemeber 2015 and was completed in June of 2019.