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. Today, the fourth “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 stormwater from the construction area. The system will significantly reduce turbidity, neutralize pH and ensure stormwater meets Administrative Order requirements before discharging into nearby Lake Washington.
*Photos pictured by Graham Construction