Project Profile: Utilities Replacement

Lyons, Colorado

Two projects the CGRS Water/Wastewater team recently completed for the Town of Lyons will affect the quality of life for some of its residents.

One project will eliminate causes of sewage backups in nearby homes – a recurrent issue and messy symptom of a deeper problem the Town needed to resolve for its residents. The other project just down the street has improved water pressure for nearby residences, but also provided firefighters with enough water pressure in the event of a blaze in the neighborhood.

Sewer rehabilitation

The CGRS team worked with Town staff to remedy occasional sewage backups in residences, discovering that a pressurized sewer line was overloading a manhole in the neighborhood, causing sewage backup on gravity inlet lines and erosive turbulence in the manhole

CGRS proposed a sewer rehabilitation design that would reroute the force main line to tie back into the sewer main about 50 feet downstream of the manhole. The solution would not only eliminate the existing issues, but it would also prevent the need to dig into the sidewalk behind the affected houses and save the Town several thousand dollars. The team also replaced the poorly functioning sewer manhole and associated inlet and outlet lines.

Water-pressure improvements

According to Aaron Caplan, Town Director of Utilities and Engineering, the Town needed to address a water pressure issue discovered when a builder applied for a permit to construct a home. The fire department couldn’t sign off on the permit because the water line that served the area did not have enough flow to sufficiently address a fire at that residence.

“We had to come up with a solution to get the fire hydrant to put out more water for this person to proceed with their building permit,” Caplan said.

CGRS solved this problem by installing an interconnection between two existing subdivision mains with 200 linear feet of an 8-inch water main and associated valves, tees, and connections. Doing so improved the water pressure to the fire hydrant as well as to the future and 20 existing homes in the neighborhood – which made homeowners happy, he said.

Challenges and solutions

As with the Eastern Corridor Utilities project our crew completed for the Town of Lyons in 2019, this job presented its share of challenges:

  • While our team suspected they might have shallow sandstone to excavate for the water main project – as sandstone was in the yards of houses in the subdivision – the extent of excavation needed was not in the original scope of work. CGRS purchased special “tiger” teeth for the excavator to rip the sandstone and rented an excavator-mounted hydraulic hammer for the toughest portions. Other contractors who completed a project a couple of blocks away also ran into sandstone, so the Town had added contingency for rock excavation with this contract, Caplan said. However, the amount of sandstone CGRS had to excavate exceeded expectations.
  • The Town had drawings of the proposed location of the water lines but not of where they were eventually installed decades ago. CGRS worked with Town staff to identify an area where the pipe might be and used a vacuum truck to pothole and eventually locate the water lines 10 feet west and off the street, though still in the Town’s right-of-way.
  • The water line was also located in the middle of a steep road so, to ensure the loader wouldn’t lose traction and slide into a parked car, CGRS enlisted a rubber-tracked excavator with better traction and that was gentler on asphalt.
  • The Town required the crew to keep the homes’ driveways open as much as possible, so the crew excavated, installed the pipe and backfilled in 20- and 40-foot sections as they snaked up the hill. Caplan noted that while there weren’t too many driveways, the crew had to work in a constrained area and he didn’t hear any complaints from residents about blocked driveways.

“Everything went really smoothly, even with the water line not being in right place and the rock,” Caplan said. “(CGRS) worked through it and kept the project moving along. We’re happy with the work that was done to resolve those issues.”

One more job

But CGRS’ job wasn’t done once the water line and sewage projects were completed. While working on the sanitary job, the Town notified the team of water bubbling out of the ground in the parking area in front of the sewage treatment plant, where CGRS was staging its equipment but not working. The leak was thought to come from a main line but, when the team exposed the main the next morning, they found a broken 2-inch polyvinyl chloride (PVC) service line. Between the team and the Town, CGRS had the parts to make the repair and turn water service back on within 6 hours of shutdown.

Caplan said it was fortunate that the leak appeared at the right time and place so that CGRS could take care of it quickly.