In the arid climate of Eastern Washington, rainfall is infrequent. When it does rain, the runoff typically contains a high concentration of pollutants that have built up on roadways during the weeks and sometime month-long dry periods between rainstorms. Therefore, removing these pollutants from the roadways with regular street sweeping is a key strategy for stormwater management in Eastern Washington. Street sweeping improves the water quality of the stormwater runoff by dealing with these solids in a dry form which is much less expensive than removing them from runoff via stormwater treatment.
One major hindrance to the street sweeping efficiency in West Richland, Washington has been the lack of a facility to handle the solid waste. The street sweepers and educator trucks require a relatively large area for maneuvering and locations to empty and clean the trucks. Large spaces are required to allow the solid waste to dry out, be properly tested for contaminants, and be stockpiled for future reuse. In 2014, The City of West Richland partnered with the Washington State Department of Ecology on the design and construction of a new Street Waste Facility to improve the efficiency of the street sweeping operation. J-U-B Engineers, Inc. designed the facility which consists of six different docks for unloading and processing of street waste from street sweepers and educator trucks. Cast-in-place concrete was the building material selected for four of the docks in order to provide the strength necessary for turning movement of the large equipment as well as a smooth surface for handling the waste and cleaning. Pre-cast concrete structures were also used for catch basins, a clarifier, and a lift station sump. The cast-in-place concrete retaining walls facilitate handling the material and provide separation between piles. J-U-B assisted the City in securing grant funding from the Washington Department of Ecology for construction of the facility. The State grant covered 75% of the construction cost for this $1 million facility. The facility was constructed by Tapani, Inc. in 2015 and concrete was provided by American Rock Products.
The new Street Waste Facility provides ample room for maneuvering of the large vehicles and recessed docks to facilitate the unloading and cleaning. Decanted stormwater is collected in an underground collection system where it receives clarification and is then pumped into the headworks of the City’s Wastewater Treatment Plant for further treatment. The six bays and large drying pad provide flexibility to process “hot loads” of potentially contaminated waste without compromising existing stockpiles. Once the solid waste has been properly tested, it can be reused as fill material on various City projects. This facility will greatly improve the efficiency of operations and is expected to allow the City to nearly double the amount of curb-miles swept each year.
This project is an excellent example of a partnership between the City of West Richland and the Washington State Department of Ecology improving water quality in Eastern Washington as well as the quality of life for residents and street sweeper operators alike.