Charlotte Ave and Vicinity Pipeline Replacement Project

Charlotte Ave and Vicinity Pipeline Replacement Project

The Project will replace approximately 0.9 miles of existing water main infrastructure on five suburban streets in Concord, CA. The purpose of the project is to upgrade aging water infrastructure by replacing sections of high-risk 4- and 6-inch asbestos cement pipe that were installed in the 1960s. Four existing fire hydrants will be replaced, and three to four new fire hydrants may also be installed. The Project is entirely within the existing CCWD treated water service boundary and will not result in an expansion of service. Construction is anticipated to occur between September 2026 and September 2027. The pipes will be transported in 20-foot sections to the project area and stored in small piles throughout the work area to reduce disruptions to pedestrian and vehicular circulation. As the Project will be under construction for a few days in front of each residence, the 20-foot-long sections of pipe will typically be stationed in one place for a maximum of one week at a time. Upon replacement, the existing lines will be abandoned in place per CCWD standards. No disruption will occur from pipe removal. A backhoe will be used to dig a trench approximately two feet wide by four feet deep on the streets within the pipeline replacement area. The trench will be covered each night with metal trench plates; wood, metal, and/or hydraulic shoring and bracing will be used as necessary to shore up the sides of the trench in all locations. Trench covering and shoring materials will be stored onsite in an area that minimizes disruption to the surrounding residents. After the pipeline is installed, the trench will be compacted and backfilled with imported aggregate base and/or excavated soils, and the site will be restored. Temporary service disruptions are possible during construction. If a temporary service disruption occurs, it will not exceed eight hours at any given time during construction. CCWD will provide advance notice to homeowners in the vicinity before the start of construction, and homeowners will be given notice 24-hours in advance of any service disruption. Finally, the asphaltic concrete (AC) pavement surface will be repaired and reconstructed to match existing conditions and conform to City standards. Up to 80 round-trip truck trips (160 one-way) are anticipated to be necessary to transport the pipes and other materials over the life of the project. No more than twenty round-trip truck trips (40 oneway) will occur on any given day and will typically be spread out over a 10-hour work period, from 7 am to 5 pm. The Project will require obtaining an encroachment permit from the City of Concord. The permit will be completed before construction starts and will contain all City of Concord requirements for the work. During the pipeline installation process, it will be necessary to flush the new lines, and up to 13,800 gallons of treated water may be discharged cumulatively during the duration of the Project. This water will be dechlorinated pursuant to CCWD's Best Management Practices (BMPs), then will be discharged into the County's storm drain system. This discharge will be covered under the Order WQ 2014-0194- DWQ GENERAL ORDER NO. CAG140001 Statewide National Pollutant Discharge Elimination System (NPDES) permit for drinking water system discharges to waters of the United States. The following equipment will be used during construction: saw cutting machine, backhoe, backhoe trailer, excavator, dump truck, boom truck, and crew vehicles. All construction materials and equipment will utilize lay down areas located within the public right-of-way but will be stationed in one place for a maximum of one week at a time. The Project site is within a suburban residential housing area, and work will occur in previously disturbed areas, including roadways within the public right-of-way and on private property. The Projects will not adversely affect natural resources such as open space areas, wetlands, riparian corridors, or areas of known cultural or historic resources. As such, impacts on natural and/or cultural resources are not anticipated. CCWD will use the following standard CCWD Best Management Practices (BMPs) to protect the environment: 1. All trash will be properly contained, removed from the work site, and disposed of on a daily basis. 2. CCWD will ensure that all raw construction materials, wastes, temporary fences, barriers, and/or flagging are removed and properly disposed of from the Project area immediately following the completion of construction. 3. The storage and handling of hazardous materials within the Project site is prohibited and any unused or leftover hazardous products shall be properly contained and disposed of off-site

Concord

Contra Costa

Citywide

Contra Costa