The SR 520 Bridge crosses Lake Washington to connect I-5 in Seattle to I-405 in Bellevue. After over 50 years of use, the bridge was showing its age and in need of safety, transit & roadway improvements. The 520 Bridge Replacement and HOV Program project has been broken down into seven phases as windstorm and earthquake-vulnerable structures are replaced and mobility improvements are made. In 2015, WaterTectonics treated stormwater on the floating bridge (phase two) of the project.
The “Montlake Phase” is in full swing with Graham Construction. WaterTectonics has been brought in again to mobilize a 300 gallon per minute WaveIonics electrocoagulation (EC) system with granular activated carbon (GAC) to treat site stormwater from the west approach construction area. The system significantly reduced turbidity, neutralized pH, and removed contaminants to meet Administrative Order limits before discharging the treated water into nearby Lake Washington.
*Photos pictured by Graham Construction