Background
This project is the result of a coordinated effort between state and local agencies and involves the drilling, cementing, permanent capping, and removal of the above-ground pipes of two abandoned oil wells located in the front yards of two homes on Firmin St, Echo Park (CA). The project lead agency, the Department of Conservation, Division of Oil, Gas, and Geothermal Resources (DOGGR), indicated that the two wells do not pose an immediate danger to the public and that although they are very old and near homes, “the amount of methane build-up in the old system is not enough to light a pilot light.” However, the wells are being permanently sealed to current standards to prevent further deterioration.
South Coast Air Quality Management District (South Coast AQMD) Air Monitoring Activities
South Coast AQMD has been working with DOGGR and the Governor’s office to implement a strategy for determining the presence of air pollutants in the affected area. The sampling plan consisted of using continuous monitors and integrated canister (or Tedlar bag) samples to measure the concentrations of methane (CH4) hydrogen sulfide (H2S), Volatile Organic Compounds (VOCs; including benzene), and other air toxics at the two well sites and in the immediately nearby community area. Additional monitoring included fugitive emission measurements of particulate matter (PM) from activities related to the well sealing.
On June 8, 2016, South Coast AQMD staff participated in a visual assessment of the physical footprint of the construction site. At this time several canister and Tedlar bag samples were collected through a probe inside the “Rogalske 10 well” on 323 Firmin St. and near the same well but at surface level. Overall, the analysis of these samples revealed that the hydrogen sulfide (H2S) concentration inside the well was above the Acute Reference Exposure Level (REL)
(30 ppb) for bag sample #10146-1, although the concentration measured in bag sample #10146-2 was below the Acute REL. Ambient H2S measurements were also taken using a hand-held monitor, as staff noticed a rather strong rotten egg smell (typical of sulfur gases) immediately over the well, and a fleeting but noticeable smell from the street.
Methane concentrations inside the “Rogalske 10 well” were above flammability levels and as high as 5.9% (canister #54553). However, methane values were much lower at the surface of the same well (676 ppm; canister #54603) and decreased to 2 ppm (typical background) in the sample collected on the street away from the well (canisters #E3374, 53465, and 54549).
Samples from inside the “Rogalske 10 well” were also analyzed for VOCs using a protocol based upon the U.S. EPA TO-15 method. Although the results of this analysis revealed elevated hydrocarbon concentrations, the measured air toxics (e.g. benzene) were not above Acute RELs, with the exception of acrolein (see Table 1 (PDF) for details). Acrolein levels in the two canister samples collected on 07/15/16 were at or above the Acute REL. However, the samples were collected close to the potential source and are not necessarily reflective of the ambient air, and acrolein is well known to be difficult to measure with current techniques. Monitoring data for acrolein are not accurate enough to be compared to health benchmarks. Measurements taken near the "Patel 1" well on 324 Firmin St. indicated that the H2S concentration was within typical ambient air levels.
On July 15, 2016, South Coast AQMD staff conducted further monitoring at the “Rogalske 10 well” at a time when operations for the permanent sealing of the two existing orphan wells begun. Additional monitoring equipment was used to also measure PM concentrations that may result from excavation activities at the well and from increased traffic from trucks and other vehicles that were present at the site. The analysis of samples collected near the bore hole and in close proximity to the excavated soil showed levels of some air toxics that were slightly higher than typical ambient air values; however, aside from the acrolein measurements noted above, none of the measured concentrations exceeded the Acute RELs. Increased real-time (1-minute) PM10 and PM2.5 levels (as high as 101 ug/m3) were also observed near the site, consistent with observations of heavy truck traffic, drilling, and soil removal operations.
Interagency Collaboration
While DOGGR is coordinating the operations to permanently seal these two abandoned oil wells, other agencies participating in this project include:
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City of Los Angeles Emergency Management Department
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State Department of Conservation, Division of Oil, Gas, and Geothermal Resources
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City of Los Angeles Mayor’s Office of Homeland Security and Public Safety
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Council District 1
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Los Angeles Fire Department
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Los Angeles Police Department
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City of Los Angeles Public Works - Bureau of Engineering
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City of Los Angeles Public Works - Contract Administration
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City of Los Angeles Public Works - Sanitation
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City of Los Angeles Public Works - Bureau of Street Services
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City of Los Angeles Department on Disability
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City of Los Angeles Department of Transportation
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City of Los Angeles Department of Water and Power
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Los Angeles Unified School District
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South Coast Air Quality Management District
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Los Angeles County Public Health
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Time Warner
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AT&T Corporation
Other Resources
Laboratory Reports