SKYPARK COMMERCIAL PROPERTIES COMMUNITY UPDATE

Los Angeles Regional Water Quality Control BoardRemote Community Meeting

July 30, 2020

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• Welcome and Introductions

• Meeting Ground Rules: How to

Participate

• Presentation

• Questions and Answers

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AGENDA

Los Angeles Regional Water Quality Control Board Chair

Irma Muñoz

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WELCOME

Type your question in the “Q&A” feature on the screen

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HOW TO PARTICIPATE

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LOS ANGELES REGIONAL WATER QUALITY CONTROL BOARD’S ROLE

• Who is the Los Angeles Regional Water Quality Control Board?

• Mission Statement

• What do we do?

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OFFICE OF ENVIRONMENTAL HEALTH HAZARD ASSESSMENT’S ROLE

• Who is the Office of Environmental Health Hazard Assessment (OEHHA)?

• Mission Statement

• What do we do?

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• Site Background and Overview• Regulatory History• Results of Investigation Completed• Vapor Intrusion Overview• Screening Level Overview• Next Steps• Schedule

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PRESENTATION OUTLINE

SKYPARK COMMERCIAL PROPERTIESSITE MAP

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SKYPARK COMMERCIAL PROPERTIES PROJECT OVERVIEW

• Hi-Shear Corporation Property(2600 Skypark Drive)• Manufactures fasteners for

the aerospace industry• Volatile organic compounds

(VOCs) leaked into theground contaminating soil, soilvapor, and groundwater

• Robinson Helicopter Property (2530 and 2540 Skypark Drive)

• Manufacture of rotorcraft and related components

• VOCs stored and used are sources of contamination

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• Dasco Engineering Property (24707, 24747, and 24701 Crenshaw Boulevard)

• Manufacture of rotorcraft and precision mechanical aircraft and space components

• VOCs stored and used are sources of contamination

• South Bay Lexus Property (24777 and 24751 Crenshaw Boulevard)

• Historical operations include manufacturing of aircraft, missiles and their components

• VOCs stored and used are sources of contamination

SKYPARK COMMERCIAL PROPERTIES PROJECT OVERVIEW

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1991-Site investigation began

1999-Soil vapor extraction (SVE) system commenced operation at the Hi-Shear property

2009-Order requiring investigation issued to Hi-Shear

2013-Tested enhanced bioremediation to remediate VOCs in groundwater

2018-Soil, Soil Vapor and Groundwater Delineation Work Plan submitted

2019-Soil, Soil Vapor and Groundwater Delineation Workplan approved

2020 Order requiring investigation of east adjacent properties of Hi-Shear Order requiring vapor intrusion assessment of Skypark Commercial Properties

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REGULATORY HISTORY SUMMARY

HOW DOES CONTAMINATION SPREAD AT A SITE?

Release at site

Impacts to soil

Impacts to soil vapor

Impacts to groundwater

Image from Livingston County Health Department

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Volatile Organic Compounds (VOCs)• Chemicals that pass easily from a liquid

into a gas state• Commonly used in industry and in the

home• VOCs in soil and groundwater can

evaporate as vapors and can collect underbuildings potentially affecting the qualityof indoor air

Trichloroethylene (TCE)• VOC used for degreasing metal parts• Also used in consumer products

Tetrachloroethylene (PCE)• VOC used in clothes dry cleaning and

metal degreasing• Also used to make other chemicals and

found in some consumer products

• Air fresheners, candles, perfume• Hairspray, hair dye, aerosolized

products• Paints, varnishes and lacquers • Adhesives, glues, markers• Cleaning agents (e.g., bleach,

ammonia)• Rubber cement and epoxy adhesives• Paint and stain removers• Carpet/rug/upholstery cleaners • Refrigerant• Insecticides, fungicides and

pesticides• Flame retardant fabrics • Furniture polish and floor polish • Dry cleaning chemicals

Source- California Water Boards

COMMON HOUSEHOLD SOURCES OF VOLATILE ORGANIC

COMPOUNDS

WHAT ARE VOCs?

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2018 Work Plan Scope of Work

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Soil Vapor Probe Locations

2018 Work Plan Scope of Work

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Groundwater Monitoring Well Locations

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SOIL VAPOR INVESTIGATION RESULTS TO DATE

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SOIL VAPOR INVESTIGATION RESULTS TO DATE

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SOIL VAPOR INVESTIGATION RESULTS TO DATE

GROUNDWATER INVESTIGATION RESULTSTO DATE

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GROUNDWATER INVESTIGATION RESULTSTO DATE

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Source: CalEPA

VAPOR INTRUSION CONCEPTUAL MODEL

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Toxicity Exposure (Dose)

Acceptable Risk Level

Screening Level

SCREENING LEVELS (SL)

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• Prioritize efforts where the most significant problems have been identified at contaminated sites

• A chemical present at concentrations above its corresponding SL does not mean there is an immediate threat but it does mean additional evaluation is generallynecessary

• SLs are very stringent and have multiple levels of assumptions built in to be protective of public health

• SLs are updated periodically

SCREENING LEVELS (SL)

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Long-Term Exposure ScreeningLevels

Short-Term Exposure Screening Levels

TCESub-slab/Soil Vapor Indoor Air

Residential 16 µg/m3 0.48 µg/m3

Commercial 100 µg/m3 3 µg/m3

PCESub-slab/Soil Vapor Indoor Air

Residential 15 µg/m3 0.47 µg/m3

Commercial 67 µg/m3 2 µg/m3

TCESub-slab/Soil Vapor Indoor Air Exposure—

Accelerated

Indoor Air Exposure

Exposure—Urgent

Residential 67 µg/m3 2 µg/m3 6 µg/m3

Commercial 267 µg/m3 8 µg/m3 24 µg/m3

SCREENING LEVELS

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NEXT STEPS

• Complete the work proposed in the 2018 Work Plan

• Conduct indoor air and subslab vapor sampling of select commercial and residential properties

• Resume onsite remediation at the Hi-Shear Property

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AREA TO BE EVALUATED FOR VAPOR INTRUSION

Indoor Air and Subslab Vapor Locations

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AREA TO BE EVALUATED FOR VAPOR INTRUSION

INDOOR AIR AND SUBSLAB SAMPLING

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Sampling Process

Indoor Air Samples Building survey: pre-

sampling questionnaire Identification of

household items that contain VOCs

Placement of canisters in targeted areas

Leave canisters for 24-hours to collect air(8-hours for business)

Return to retrieve canisters

Sub-slab (directly beneath foundation, typically in garage) or perimeter soil vapor samples collected (outside) for correlation with indoor air samples

Source: Santa Ana Regional Water Quality Control Board

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• Air purifiers

• Sealing openings- filling in cracks in the floor slab and gaps around pipes and utility lines

• Vapor barriers- placing sheets of strong plastic beneath a building to prevent vapor entry

• Passive venting-installing a venting layer beneath a building

• Sub-slab depressurization- connecting a blower to a small suction pit dug into the slab to vent vapors outdoors

VAPOR INTRUSION MITIGATION MEASURES

Source: Santa Ana Regional Water Quality Control Board

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2nd Half of 2020 Complete work proposed in the 2018 Work Plan Conduct subslab vapor and indoor air sampling at the

following areas: Hi-Shear property Robinson Helicopter, Dasco Engineering and South

Bay Lexus properties Accelerated response zone between Crenshaw Blvd

and 247th and 248th St in the City of Lomita Resume operation of the SVE system at the Hi-Shear

property 2021

Continue vapor intrusion assessment Conduct interim remediation Public Meeting

Upcoming Work Activities

Type your question in the “Q&A” feature on the screen

QUESTIONS & ANSWERS

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Q&A PANELISTS• Dr. Arthur Heath, PhD: Site Cleanup Program Manager, LA

Water Board

• Jillian Ly, PE, PMP: Site Cleanup Program Unit 4 Chief, LA Water Board

• Dr. Jim Carlisle, DVM, MSc: Toxicologist, Cal EPA Office of Environmental Health Hazard Assessment (OEHHA)

• Tamarin Austin: Attorney, Office of Chief Counsel, State Water Board

• Steve Van der Hoven, PhD, PG: Environmental Consultant for Hi-Shear, Genesis Engineering and Redevelopment

For questions or additional information regarding the Skypark Commercial Properties, please contact:

Jillian Ly, PE, PMPSenior Water Resource Control EngineerJillian.ly@waterboards.ca.gov or (213) 576-6664

Susana Lagudis (se habla español)Public Participation SpecialistSusana.lagudis@waterboards.ca.gov or (213) 576-6694

MEETING EVALUATIONUse the following https:https://www.surveymonkey.com/r/Q2956YVor hold your mobile phone to the screen and use a QR Code reader to complete the meeting evaluation

CONTACT INFORMATION

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