Site work for a water / sewer project in Paramount, California. Working plans call for site work for a water / sewer project.

***As of December 11, 2023. No bids received. Monitoring Well Installation. Questions regarding the bid specifications should be directed to Celina Sanchez at (562) 220-2158 and/or at Csanchez@paramountcity.com he following scope of work will be conducted at the site (see Figure 1). o Drill, install and develop three (3) new 2-inch diameter groundwater monitoring wells (wells MW-1, MW-2, and MW-3; see Figure 2). Total depth of the boreholes/well are expected to be between 30 and 50 feet below ground surface( FT-bgs). Permitting: City of Paramount will not require any permits for this well installation. AECOM will be responsible for obtaining a permit for monitoring well installation from Los Angeles County Department of Public Health (LACDPH). Utility Clearance: The Contractor shall clear the first five FT-bgs using triangle clearance for utilities using a hand auger. At least 48 hours prior to ground-disturbance activities, the well locations will be marked with white spray paint and/or flagging by AECOM. Underground Service Alert will be contacted to locate and mark the underground utilities and pipelines in the area of proposed work. A geophysical survey will be performed by others to locate utilities and subsurface structures in the vicinity of the work areas prior to mobilization. Storm Water Prevention: The Contractor shall review the nearby storm drains and sewer access points on site to put in place any required prevention methods that will mitigate material from the installation of the monitoring wells from entering. Materials such as silt screen and hay waddles are acceptable. They should be in place prior to any ground disturbance activities and removed once all site activities have been completed. Soil Borings: Drilling will be conducted by a California-licensed C-57 drilling contractor, and drilling activities will be overseen by a California Professional Geologist (AECOM). The borings for the wells will be advanced to the top of the Bellflower Aquitard, anticipated to be encountered between 30 to 50 feet bgs. Ground water is expected to be encountered between 15 and 25 feet below ground surface (bgs). Given the location and access limitations, a small track-mounted drilling rig with both direct-push and hollow-stem auger capabilities will be needed. The soil borings will be advanced using direct push technology (DPT) drilling techniques to collect continuous soil cores in order to evaluate subsurface lithology and collect soil samples for field screening and/or chemical analysis. The selected drilling contractor will use Geoprobe(TM) drilling equipment that utilizes a "dual tube" system. The dual tube system advances a larger outer casing along with a smaller diameter inner casing that collects the soil core. The acetate sleeve cores will be laid out on plastic sheeting and the lithology will be logged in detail in accordance with industry standard by the onsite Geologist. Well Installation: Upon completion of each exploratory borehole, the final monitoring well design will be based upon conditions encountered in the field. Figure 3 shows the generalized proposed well design. Each well will be constructed using the same drill rig fitted with eight-inchdiameter hollow stem augers to ream the borehole that had been advanced using the direct-push method. The wells will be constructed through the hollow stem augers. Each monitoring well will be constructed of 2-inch-diameter schedule 40 polyvinyl chloride (PVC) well casing with 10 to 15 feet of 0.020-inch machine slot PVC screen extending to the final depth of the well, which is anticipated to be approximately between 30 and 50 feet bgs. The filter pack will be gravity fed through a tremie pipe in a continuous manner that avoids bridging. The filter pack will not be allowed to freefall more than 20 feet from the bottom of the tremie pipe to the top of the filter pack or the seal interface. A device will be used to sound the level of the filter pack throughout the backfilling process. Upon completion of installation of each filter pack interval, portion thereof, or neat cement grout annular seal, the depth of the top of that filter pack will be determined by an accurate sound meter. The filter pack will consist of siliceous #3 (or similar) washed and kiln-dried sand with little to no fines and no foreign material. The filter pack will extend from bottom of boring to approximately one (1) foot above the top of the screen. A minimum 2-foot-thick bentonite transition seal will be place above the sand pack. A cement/bentonite grout (consisting of up 95% Portland Type I or II cement and 5% bentonite powder) will be placed by tremie pipe from the top of the bentonite seat to approximately six inches below grade. The monitoring wells will be completed with 12-inch diameter surface-finished traffic-rated well vaults. Well Development: The monitoring wells will be allowed to sit for a minimum of 24 hours after installation before developing. Prior to development the depth to groundwater and the total well depth will be measured.