Remediation

The Remedial Action Plan outlines the work that will be conducted to remediate the Carousel neighborhood.

This plan is based on extensive testing in the neighborhood, under the oversight and review of the Los Angeles Regional Water Quality Control Board (Water Board), the lead state agency for the project. The Water Board approved the Remedial Action Plan on July 10, 2015.

Three methods of remediation will be used:

1. excavation;
2. soil vapor extraction (SVE) and bioventing; and
3. sub-slab depressurization (SSD).

These methods were approved by the Water Board to address the conditions in the neighborhood. For more detailed information about these methods, please call the Carousel Community Information Line at (310) 857-2335.

Remediation began in spring 2016 and will occur in clusters of 10-16 homes; it will take a few months to complete remediation in each cluster. The goal is to complete all of the excavation work in the Carousel neighborhood within five to six years once work begins.

The work conducted at each property was determined based on the findings of the environmental investigation for that specific property, and is outlined by address in the Remedial Action Plan. For specifics on a particular property, please call the Carousel Community Information Line at (310) 857-2335. Closer to the date of an individual property’s remediation, a Property Specific Remediation Plan will be prepared.

Work conducted at each property varies because the distribution of impacted soil is not consistent across the neighborhood. Remediation at each property was determined based on the testing and findings from the environmental investigation at that property, and has been approved by the Water Board. All properties will benefit from the SVE and bioventing system being installed throughout the neighborhood, and all properties are eligible for a sub-slab depressurization system upon request.

All residents are encouraged to participate in the remediation program. If a homeowner or resident refuses to participate, it will impact the remediation at neighboring homes, though to what extent will be determined on a case-by-case basis as it is dependent on many factors, such as the layout of the homes.

The city streets and sidewalks are barriers and prevent direct contact with the soil. These areas will be remediated by the SVE and bioventing system.

Each cluster will be surrounded by 12-14 ft. high sound panels to alleviate noise. Dust and odors will be managed by the following:

1. a water mist; and
2. odor suppressing compounds.

Dust, sound, and odors will be monitored throughout the process to monitor the impacts in the neighborhood.

Excavation will occur around pools; pools will not be removed.

Please call the Carousel Community Information Line at (310) 857-2335.

The technologies that will be used to remediate the neighborhood include: (1) soil vapor extraction and bioventing, and (2) sub-slab depressurization.

1. Soil vapor extraction (SVE) and bioventing are two technologies that work hand-in-hand to 1) remove vapors from the soil and 2) draw in oxygen to promote the natural breakdown of compounds in the soil. By working together, these technologies are able to more effectively remove contaminants from the soil.
2. Sub-slab depressurization (SSD) uses a fan to remove air from below the floor slab of a home and exhaust it above the roof to minimize any potential for vapor intrusion into the residence.

Both technologies are proven, have been widely used across the country, and have been approved by the Water Board for this project. They are also recognized by the U.S. Environmental Protection Agency (EPA) and the California EPA as effective and reliable remediation technologies.

Monitoring will be conducted throughout the site and at the off-site SVE treatment facility. This includes periodic monitoring and testing of the sub-slab soil vapor probes throughout the neighborhood. The results will be submitted to the Water Board and will be available to the public.

The SVE and bioventing system will operate until the Water Board approves it to be turned off based upon monitoring data. We expect it to operate for 30 to 40 years.

For the 29 homes requiring an SSD system, the system will operate for approximately 30 to 40 years. For those that request an SSD system, the system will also be operational for the same duration, but homeowners have the option to stop operation earlier if desired.

These estimates will be refined once the SSD and SVE and bioventing systems are operational.

Twenty-nine (29) properties have been identified by the Water Board to receive the SSD system. To see if you are one of these 29 properties, please call the Carousel Community Information Line at (310) 857-2335.

Yes, Shell is offering installation of an SSD system to any of the homeowners in the Carousel neighborhood. To request an SSD system, please call the Carousel Community Information Line at (310) 857-2335.

The SSD system uses approximately as much power as a 100 watt light bulb. Electricity costs related to the SSD System will be paid for or reimbursed by Shell.