The City of Delta is getting a lot of bang for the buck as it embarks on three street maintenance projects in the City of Delta. The city budgeted a total of $500,000 for street improvements in 2017; the three projects will cost a total of $393,536 but will extend the life of about 11 percent of the city's street network.
Delta City Council members accepted three separate bids at their March 7 meeting:
• GMCO was awarded a $107,998 bid to chip seal and fog seal 2.4 miles of Crawford Avenue and H Road to the city limit. Chip seal consists of surface treatment of asphalt, followed by an aggregate cover that's left in place for 24 hours. Fog seal is a surface treatment of diluted asphalt emulsion.
• Intermountain Slurry was awarded a contract for $66,998 to treat sections of 5th Street, 7th Street and Riley Lane (a total of 1.4 miles) with a micro-surfacing asphalt preventative maintenance treatment. Micro-surfacing involves laying a mixture of dense-graded aggregate, asphalt emulsion, water, polymer addition and mineral fillers.
• Andale Construction was awarded a bid of $221,038 for road maintenance in Emerald Hills, Valley Garden, Orchard Estates, Pioneer Place, Fox Hollow and Cottonwood Lane -- a total of 3.4 miles. A high density mineral bond application will be used. This product is described as a unique emulsified proprietary blend of fine aggregates that helps protect the asphalt surface from breakdown by UV exposure. The treatment can extend the life of a road by 10-12 years.
City staff based project priorities on a 2016 road survey that analyzed the condition of all city streets. In addition to the condition of the road, staff considered traffic load, age, road usage, drainage and types of defects when determining the appropriate method of treatment.
"It's important to complete the right repair on the right road at the right time," city engineer Ellen Michelson told council members.
Prior to the regular council meeting, Michelson and Steve Glammeyer, public works/utilities director for the City of Delta, outlined various pavement applications at an hour-long work session. Instead of tackling the worst road surfaces, the city is adopting a maintenance strategy that first addresses the roads on the verge of requiring more advanced treatment, to extend a road's life cycle at a lower cost.
The gamut of road maintenance runs from crack sealing and other routine maintenance, to complete reconstruction, the costliest option. Pavement typically lasts about 20 years, Michelson and Glammeyer said; with proper maintenance, road life can be extended to 40 years.
They also discussed the street survey completed by two high school interns last summer. The interns looked at rutting, raveling, heaving, weed growth, cracks, patches, potholes, drainage and ride quality. The scoring system they employed is one used across the nation. Based on scores ranging from 0-100, overall pavement condition in Delta averaged 76. Most of the streets in Delta fall into the "satisfactory" category; none have completely failed.
The city has never used either the micro-surfacing or the high density mineral bond application, but staff members have seen and reviewed both products.
With micro-surfacing, roads can be opened to travel in one to four hours. The high density mineral bond application will require a 24-hour road closure for curing, which is one reason it was selected for residential subdivisions and not highly traveled arterials. Caleb Fiske, a representative of Andale, said public meetings will be held and flyers will be distributed to apprise subdivision residents of the accommodations that will be made for them during the 24-hour road closure. No time frame has been set for the project, but city staff anticipates the treatment will be applied after school has been dismissed for the summer.