2009 Preventative Street Maintenance - WO 116

Table of Contents

Preventative Maintenance Summary

Affected Streets

Funded By

Current Status

Questions and Comments

Frequently asked Questions

Preventative Maintenance Summary

In 2004, the City of Lake Oswego implemented the Street Maintenance Fee to fund the annual Preventative Street Maintenance and Rehabilitation Program.  This yearly program, with a cost of 1.2 million dollars per year, maintains 180 miles of paved streets within our community for a cost of approximately $3.75 per home per month. 

Even the best of surfaces are subject to the wear and tear caused by time, weather, and traffic. No surface is permanent.  The expectant life cycle of a newly built asphalt street is approximately 20 years.  Although untreated asphalt pavement is still adequate for traffic after several years of use, pavement deterioration has already begun.  A slurry seal maintenance program undertaken before significant pavement deterioration can save significant costs, and is vital to proper pavement maintenance.

So what is slurry seal?  Slurry seal is a petroleum-based emulsion product, blended with fine aggregate rock, mixed on-site in by the contractor, and then applied evenly across the entire surface of an asphalt street.  A slurry seal is typically 1/4 to 3/8 of an inch thick.  Like the finish on a deck or paint on a house, a slurry seal provides a new protective surface to an existing asphalt street. By sealing the street, the base of the road is protected from water damage and the surface is protected from weathering.

Using our Pavement Management System, we select streets that fall within a condition range best suited for this treatment. Each street is inspected to verify the condition and ensure that it is a candidate for slurry. Some streets are at a level of deterioration requiring more extensive and costly repairs, such as a structural dig out and an asphalt overlay. Our goal is to protect good street surfaces with slurry, postponing costly overlays for several years.

At a cost of approximately $1 per square yard, compared to $7 +  per square yard for an overlay, a slurry seal is an extremely economical way to extend the serviceable life of a residential street by 7 to 10 yrs.

Before your street can be slurry sealed, the surface must be adequately prepared.  Crews will be sweeping, sealing cracks and patching street defects prior to the actual slurry seal.   These activities may require numerous visits to your street due to the specialized nature of each repair method.  The contractor will strive to keep the disturbance to a minimum; however, this work can be dusty and noisy.  We ask that you, the homeowner or resident, trim tree branches, brush or vegetation that grow over the asphalt or will impede the contractor's equipment.  This will also protect your landscaping as broken branches can be unattractive and harmful to the health of trees and shrubs.

During the slurry seal application, access to your street will be interrupted for a maximum of 8 hours, one day only, unless the contractor is delayed due to equipment failures, weather-related problems, or other unforeseen reasons. If your street is not sealed as scheduled, it will be added toward the end of the list and you will be notified again 48 hours in advance of the contractor returning and sealing your street.

No traffic will be allowed on the street after the slurry has been placed and is drying.  You will need to plan ahead and park on another street if you come and go during the drying time.  The slurry generally takes 4 to 6 hours to dry but may take 8 hours or more depending on temperature, cloud cover, humidity and wind conditions.

Services such as police, fire, mail, sanitation, etc., should not be significantly affected during the slurry seal application.  All services will be notified of the maintenance schedule so reasonable accommodations may be made.   

Affected Streets

Work on affected streets are highlighted in the project map. Click here to view Project Map.

Click here to view project schedule.

Funded by

Street Maintenance Fees

Current Status

The City Council awarded this project to Blackline on June 16, 2009. Construction to begin the week of July 13th.

If you have any questions about this project, please contact Crystal M. Shum, P.E. Associate Engineer direct at 503.697.7420 or click here to send her an e-mail.