City planning to add water mains under Missouri, Sun rivers; $866,028 contract on Tuesday’s commission agenda
Millions of dollars worth of public works projects are in either in progress or planned for the coming years in Great Falls.
One of those projects is installing additional water mains crossing under the Missouri River and the Sun River. The additional mains would ensure adequate water pressure and quantity to the expanding city and provide redundancy for unexpected repairs on the city’s existing mains, according to Public Works.
During Tuesday’s meeting, the City Commission will consider awarding a $866,028 contract to Thomas Dean & Hoskins Engineering (TD&H) for the project.
The city received three proposals for the project and a five-person committee reviewed and scored those proposals. TD&H scored highest.
The city is proposing to install two new water main crossings under the Upper Missouri River and Sun River using Horizontal Directional Drill methods. The project will include some open cut trenching methods for a portion of the water main installation and at connections.
According to city documents, a new 24-inch fusible C905 PVC pipe will be designed for directionally drilled installation under the Missouri River from Verde Park to Meadowlark Park. Additional open trench pipe installation will be constructed through parks and city rights-of-way in order to complete connections to the existing distribution system.
A new 20-inch water main of fusible C905 PVC material will be designed and bid for directional drilling installation under the Sun River, east of the 6th Street Southwest bridge.
The scope of work included in the recommended contract includes:
Design work consisting of:
- Securing necessary permits from Montana Department of Environmental Quality, Burlington Northern Santa Fe, Montana Department of Transportation, and Fish Wildlife and Parks, among others;
- Conduct geotechnical investigation both on land and in the Missouri and Sun River channels;
- Surveying for control points and project layout;
- Land acquisition for both temporary work and final easements;
- Produce bidding documents;
- Conduct project update meetings;
- Due to the technical nature of the HDD, provide project inspection duties.
TD&H would also be required to: conduct public hearings, as needed, to keep the public informed of the project progress and schedule; provide for a contractor pre-qualification screening process to ensure the city has a qualified and experienced pool of contractors for bidding the project.
This project is being funded through the city’s Water Capital Improvement Fund.
The Gore Hill water tower project is underway and will add water pressure on the system. The new tower should be operational by this fall, Dave Dobbs told the City Commission during their May 1 work session.
Work on the water treatment plant started in 2016 and the bulk of the $30 million project should be completed this summer, Dobbs said.
The public works department is doing a study to start planning for updating the city’s water pumps.
The oldest water pump in the city’s system dates to 1923, Dobbs said.
Public Works is continuing their work to replace water main since fairly old pipes remain in the system. Dobbs said the city has done about $2 million worth of work annually over the last 20 years.
The city had 120 breaks a year 22 years ago and with the focus in replacing those water mains, the department is “ratcheting down” the number of breaks, Dobbs said.
The Public Works department also handles road construction and Encino Drive is among the roads that will be reconstruction this year. The second phase of the Encino Drive project will be completed in 2019.
There are 22 subdivisions in the works throughout the city, Dobbs said, and the city inspects the infrastructure installed by developers.
In 2003, the process changed from developer inspections to city inspections and the city charges fees for those inspections. But it can be challenging to have the appropriate number of inspectors available for the workload since the project volume varies citywide, Dobbs said.
City Manager Greg Doyon said that if the city is going to adopt infrastructure into the city, they want full inspections to protect the city. If the work isn’t done properly and the city has to fix it, the taxpayers end up eating that cost, Doyon said.