Installation of two multiple-well monitoring sites near a proposed supplemental recharge well project, Central Basin, Los Angeles County, Federal Fiscal Year 2016 Active
The Water Replenishment District of Southern California (WRD) is planning to construct an advanced water treatment facility and three supplemental injection wells in a recharge area in the coastal plain of Los Angeles County.
Problem
When the nearby spreading basins are unavailable for recycled water recharge or do not have sufficient capacity to hold local storm water during wet periods, up to 5 million gallons per day of treated water would be directed to the injection wells. There is a short-term need to estimate time of travel to a nearby production well and identify the potential for undesirable trace elements (i.e., arsenic) to mobilize into solution, as well as a long-term need to monitor the quality of injected water in the aquifers.
Objective
The study objective is to characterize the geologic, hydrologic, and chemical characteristics of the aquifer system beneath a critical managed aquifer recharge area of the Los Angeles coastal plain, to better inform the design and construction of a supplemental recharge well project.
USGS proposes to install two multiple-well monitoring sites (MW1 and MW2), and collect geologic, hydraulic, and water chemistry data needed for the final design and operation of the supplemental recharge well project.
Science Plan
Core samples will be collected for the purpose of understanding potential sources of trace elements within the aquifer sediments. Sequence stratigraphic methods will be used to identify sequence boundaries and correlate strata between the monitoring sites. Slug tests will be conducted in each well to estimate the hydraulic properties of the local aquifers. Water samples for the analysis of inorganic constituents, dissolved gases, dissolved organic carbon and optical properties, stable and radiogenic isotopes will be collected to assess the quality of water and characterize the source, movement, and relative age of water between the monitoring sites prior to any injection.
This project will contribute to the USGS' ability to ensure adequate quantity and quality of water to meet human and ecological needs in the face of growing competition among domestic, industrial-commercial, agricultural, and environmental uses. The project aligns with the Water science mission to define and better protect the quality of the Nation's water resources by producing infrastructure and data to better inform the design and construction of a new recharge well project, critical for supplementing existing sources of recharge to the local groundwater basin.
Below are other science projects associated with this project.
Los Angeles Coastal Plain Groundwater-flow Model
Geohydrologic Study of the Central and West Coast Basins of Los Angeles County
- Overview
The Water Replenishment District of Southern California (WRD) is planning to construct an advanced water treatment facility and three supplemental injection wells in a recharge area in the coastal plain of Los Angeles County.
Sources/Usage: Public Domain. View Media DetailsMap showing the location of a planned advanced water treatment facility and three supplemental injection wells (GRIP), in the Central Basin, Los Angeles County, California. Problem
When the nearby spreading basins are unavailable for recycled water recharge or do not have sufficient capacity to hold local storm water during wet periods, up to 5 million gallons per day of treated water would be directed to the injection wells. There is a short-term need to estimate time of travel to a nearby production well and identify the potential for undesirable trace elements (i.e., arsenic) to mobilize into solution, as well as a long-term need to monitor the quality of injected water in the aquifers.
Objective
The study objective is to characterize the geologic, hydrologic, and chemical characteristics of the aquifer system beneath a critical managed aquifer recharge area of the Los Angeles coastal plain, to better inform the design and construction of a supplemental recharge well project.
USGS proposes to install two multiple-well monitoring sites (MW1 and MW2), and collect geologic, hydraulic, and water chemistry data needed for the final design and operation of the supplemental recharge well project.
Science Plan
Core samples will be collected for the purpose of understanding potential sources of trace elements within the aquifer sediments. Sequence stratigraphic methods will be used to identify sequence boundaries and correlate strata between the monitoring sites. Slug tests will be conducted in each well to estimate the hydraulic properties of the local aquifers. Water samples for the analysis of inorganic constituents, dissolved gases, dissolved organic carbon and optical properties, stable and radiogenic isotopes will be collected to assess the quality of water and characterize the source, movement, and relative age of water between the monitoring sites prior to any injection.
Sources/Usage: Public Domain. View Media DetailsA crew and equipment from the USGS Research Drilling Program will bore to a depth of ~800 feet and install four wells at targeted depths, to construct two multiple-well monitoring sites. This project will contribute to the USGS' ability to ensure adequate quantity and quality of water to meet human and ecological needs in the face of growing competition among domestic, industrial-commercial, agricultural, and environmental uses. The project aligns with the Water science mission to define and better protect the quality of the Nation's water resources by producing infrastructure and data to better inform the design and construction of a new recharge well project, critical for supplementing existing sources of recharge to the local groundwater basin.
- Science
Below are other science projects associated with this project.
Los Angeles Coastal Plain Groundwater-flow Model
The Los Angeles Coastal Plain Groundwater-flow Model (LACPGM) is a tool to help water managers better understand groundwater flow and seawater intrusion in the Los Angeles coastal plain basins. It is the culmination of years of data collection and studies in the area and builds on our understanding of the area’s geology and hydrology obtained through the geologic and groundwater flow models.Geohydrologic Study of the Central and West Coast Basins of Los Angeles County
Using the new information, along with the recently acquired seismic reflection data, USGS scientists and co-workers have been able to develop a much more detailed understanding of the stratigraphy and structure of the Central and West Coast Basins. - Publications
- Partners