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Alhambra Operable Unit

The San Gabriel Valley Area 3 Superfund Site or "Area 3" includes an approximate 18-square-mile area of groundwater contamination underlying the cities of Alhambra, San Gabriel, San Marino, South Pasadena, Rosemead, and Temple City.EPA currently is conducting a remedial investigation of regional groundwater contamination in Area 3. This assessment also involves facility investigations in cooperation with the Los Angeles Regional Water Quality Control Board (RWQCB) as part of an effort to identify Potentially Responsible Parties (PRPs) and associated sources of groundwater contamination. EPA currently is reviewing investigation data and historical records and will identify PRPs in the near future

Tags: contamination toxics

Baldwin Park Operable Unit

The Baldwin Park Operable Unit addresses multiple, commingled plumes of groundwater contamination which have resulted in an area of contamination over a mile wide and eight miles long. The most prevalent contaminants in the groundwater are trichloroethene (TCE), perchloroethylene (PCE), carbon tetrachloride, perchlorate, and N-nitrosodimethylamine (NDMA).Other volatile organic compounds (VOCs) are also present, including the chemical 1,4-dioxane, and 1,2,3-trichloropropane. The peak contaminant concentration measured in groundwater in the Baldwin Park area is 38,000 ug/l PCE; more than 7500 times the maximum contaminant level (MCL) allowed by Federal and State law.

Tags: contamination toxics TCE PCE "chlorinated solvents" "vapor intrusion"

El Monte Operable Unit

The San Gabriel Valley, California, El Monte Operable Unit (Area 1) is a ground water plume that runs along the axis of the Rio Hondo Wash and the Salt Pit Wash in the San Gabriel ground water basin in El Monte, Los Angeles County, California. The plume also parallels the San Gabriel River to the east. It is approximately 4 miles long and 1.5 miles wide. Some of the detected contaminants include: perchlorate (used in solid rocket fuel), hexavalent chromium (used in metal plating), N-nitrosodimethylamine (NDMA - found in liquid rocket fuel), 1,4-dioxane (a stabilizer in chlorinated solvents), trichloroethylene (TCE), perchloroethylene (PCE), and other chlorinated solvents.

Tags: contamination toxics TCE PCE perchlorate chromium

Puente Valley Operable Unit (Area 4)

PVOU is a ground water plume that runs along the axis of the San Jose Creek in the San Gabriel ground water basin in La Puenta, Los Angeles County, California. The plume is about 1 mile long and 1 mile wide. Ground water is contaminated with trichloroethylene (TCE) and perchloroethylene (PCE), according to analyses by State agencies and local water companies. Many public wells in the area exceed the EPA Suggested No Adverse Response Levels (SNARL) for TCE and PCE. Approximately 100,000 people are affected.

Tags: contamination TCE PCE "vapor intrusion" "chlorinated solvents"

San Gabriel Valley Groundwater Basin

The SGV's groundwater Basin has the distinction of being one of the most contaminated in the nation.The SGV is divided into several "Operable Units":Alhambra, Baldwin Park,El Monte,South El Monte, Puente Valley,and Whittier Narrows.It is contaminated from the ground disposal—dating back to World War II— of synthetic organic compounds used primarily as solvents in industrial and commercial activities...high concentrations of volatile organic compounds (“VOCs”) were found in Azusa in 1979 near a major industrial complex. In 1997, newly detected contaminants, perchlorate and “NDMA” liquid/solid rocket fuel, complicated and delayed progress of cleanup activities.

Tags: contamination toxics perchlorate VOCs

South El Monte Operable Unit

Contamination in the SEMOU consists primarily of volatile organic compounds with perchlorate concentrations in certain wells exceeding the new state notification level of 6 ppb. Furthermore, cleanup has been complicated by the presence of low concentrations of 1,4-Dioxane in the OU. The area is generally characterized by shallow groundwater contamination that is mostly contained in the upper 100 feet of the aquifer; however some contamination in the northwest and southern portions of the operable unit has migrated below 100 feet into the intermediate zone aquifers currently used for potable supplies.

Tags: contamination toxics

Whittier Narrows Operable Unit

In 1999, the United Stated Environmental Protection Agency (EPA) issued an amendment to the Record of Decision for the Whittier Narrows Operable Unit (WNOU) which identified the need for a groundwater extraction barrier approximately ¼ mile north of the Whittier Narrows Dam to halt the flow of contamination traveling towards Central Basin. To form an effective containment barrier, five or six extraction sites were required to remove and treat a total of about 12,000 gpm extracting from both the shallow and intermediate zone aquifers

Tags: contamination remediation doesn't have any shared maps.

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