As we've reported before, CPANA is in the process of conducting a year-long pre-drilling air quality benchmark study. We recently received results from the third month of monitoring.
CPANA uses a stainless steel sorbent tube placed in a secured location outdoors in Southern Lewisville, just down-wind from a future drill site. The tube passively soaks up contaminants from the air and is exposed for about a month. After exposure, the tube is sealed up and shipped to a laboratory where it is analyzed by thermal desorption - gas chromatography / mass spectrometry. The group is looking for the concentration of Benzene, and the top 9 other volatile organic compounds (VOCs).
The following compounds and concentrations were found for the sampling period of 9/19/2010 - 10/18/2010:
- Benzene was not detected. The limits of detection for this sample puts benzene below 0.05 ppb.
- Isopropyl Alcohol was detected at 0.23 ppb. This is standard rubbing alcohol used for medical procedures and as a household solvent or astringent. It can also be used as a fuel additive.
- Acetic Acid was found at 0.15 ppb. Commonly known as vinegar, but also used in industry as a feedstock. It can be found in nature as a fermentation byproduct of fruit spoilage. It may be used as a household cleaner or used in food preparation.
- Cyclohexanone was found at 0.13 ppb. A chemical precursor to the manufacture of nylon, this compound is a product of the oxidation of cyclohexane. LTESL (health) = 20ppb, under review.
- p-Xylene was found at 0.10 ppb. This solvent is similar to Benzene, but with two additional methyl groups added. The ortho, meta, and para isomers (the o, m, or p prefix) indicate where on the molecule the methyl groups are added. According to CDC, xylene is also found in automobile exhaust, and comes from industrial sources. LTESL (health) = 42 ppb for all 3 isomers.
- Pinene was found at .07 ppb. (This is a natural compound from pine trees, which are located near our sample box)
- Dodecane was found at 0.03 ppb. This is a 12 carbon alkane hydrocarbon that is a component of diesel and aviation fuel. LTESL is 350 µg/m3
- Isocyanato Cyclohexane was found at 0.03 ppb. A yellowish liquid with an irritating odor. Insoluble in water. Flash point 127°F. Very toxic by inhalation, skin absorption and ingestion. Used to make pharmaceuticals and agricultural chemicals. LTESL (health) is 0.4 ppb.
- Tridecane was found at 0.03 ppb. This is a 13 carbon alkane hydrocarbon that is a component of diesel and aviation fuel. It is also naturally produced by some stinkbugs as a defense. (Note that our sample box has screen to keep insects out, and we check for insects when we change tubes). LTESL is 350 µg/m3
No other compounds were detected in this sample. Concentrations are given in parts per billion (ppb). Overall MOU (margin of uncertainty) is +/- 16.8%. Laboratory results are attached.
Friday, October 29, 2010
Saturday, September 4, 2010
CPANA Gets Second Lewisville Air Quality Screening Results
Central Park Area Neighbors Association (CPANA) this week received the second set of air quality screening results in its planned year-long benchmarking of Lewisville ambient air prior to the beginning of gas drilling activities in Southern Lewisville.You can read more about the sampling and testing methodology in CPANA's post on the first sample.
No concentrations were found to exceed any health-based comparison values. For conservative comparison, we used TCEQ's Long Term ESLs (LTESL)
- Benzene was detected at .08 ppb. LTESL is 1.4 ppb
- Pinene was the most abundent VOC detected, at .14 ppb. (This is a natural compound from pine trees, which are located near our sample box)
- Hexadecane was found at .10 ppb. This compound is a 16-carbon alkane also known as cetane. Hexadecane is a diesel component or additive. (LTESL 350 ug/m3 - no ppb value available)
- Dichlorodifluoromethane was found at .09 ppb, though our laboratory is not accredited on that compound. This CFC is otherwise known as Freon 12 or R-12. It was used in vehicle air conditioners made before 1994, and its manufacture has been banned. LTESL is 1000 ppb.
- Toluene was found at 0.06 ppb. Toluene is a solvent, but EPA says the principal source of toluene in ambient air is automotive emissions. LTESL is 330 ppb.
- Heptadecane was found at 0.06 ppb. TCEQ doesn't list a ppb LTESL for heptadecane, but the long-term ESL is listed as 10 ug/m3. We calculate our sample was about 0.56 ug/m3.
- p-Xylene was found at 0.06 ppb. LTESL based on odor is 42 ppb. STESL (health) is 58 ppb.
- Octadecane was found at 0.05 ppb. LTESL is 10 ug/m3
- o-Xylene was found at 0.05 ppb. LTESL based on odor is 42 ppb. STESL (health) is 380 ppb.
- Pentadecane was found at 0.04 ppb. No LTESL is found at this point, but we'll research this further. Pentadecane is a component of diesel fuel, and a fragrance agent.
Note that other compounds likely were present, but only the top 10 found are being quantified in our screening, and the laboratory has limits of detection. So any other compounds would have been at concentrations lower than the 0.04 ppb of Pentadecane.
Monday, August 16, 2010
CPANA Gets First Lewisville Air Quality Screening Results
CPANA today received the first set of results from a planned year-long screening of air quality before natural gas drilling takes place.
We are using an independent laboratory to analyze diffusion tubes which are exposed to the air near one of the proposed future drill sites. By getting a good benchmark of current air quality, we hope to be able to detect any changes in quality after drilling and gas production begins.
Initial Results:
The tube was analyzed for Benzene, and the top nine other volatile organic compounds (VOCs) found.
Benzene was below the limits of detection, which is 3.9 ng for the tube. According to the lab, this limit would be equivalent to about 0.076 parts per billion (ppb), which is well below the 1.4 ppb long-term effects screening level, and the short-term 54 ppb ESL. Because benzene was not detected, we know that our levels are below 0.076 ppb.
Only three other compounds were detected, and none exceeded long term or short term effects screening levels (ESLs):
- 1R-.alpha.-Pinene at 0.15 ppb (Long term ESL is 1.0 ppb)
- Toluene at 0.03 ppb (Long term ESL is 330 ppb)
- m/p- Xylene at 0.02 ppb (Long term ESL is 42 ppb)
Toluene and Xylene are both solvents used in a variety of products, and part of the BTEX (Benzene, toluene, ethyl-benzene,xylene) quartet of hazardous chemicals that are sometimes emitted from natural gas operations.
According to an EPA fact sheet on Toluene, automobile emissions are the principal source of toluene emissions in ambient air. According to CDC, xylene is also found in automobile exhaust, and comes from industrial sources. The CPANA air sampling station for this test is located away from idling automobiles and well setback from nearby streets.
Pinene is a natural compound produced by pine trees, some of which surround the testing site.
Sampling Method
Samples are taken by using a diffusion tube exposed to the ambient air in a locked, ventilated box near the proposed drill site. Diffusion tubes are stainless steel tubes containing a sorbent material that passively soaks up air contaminants over a specified time period. The tubes are maintained with a strict chain of custody, installed under seal and witnessed by at least two CPANA board members. The completed sample is mailed to an analytical laboratory with no ties to any of the local natural gas operators.
The initial sample was taken from 6/23/2010 - 7/24/2010. Overall MOU (margin of uncertainty) is +/- 16.8%. The laboratory is certified for the analytical work, but ppb numbers take into account exposure times provided by CPANA, and for which they have no control.
Laboratory results are attached.
We are using an independent laboratory to analyze diffusion tubes which are exposed to the air near one of the proposed future drill sites. By getting a good benchmark of current air quality, we hope to be able to detect any changes in quality after drilling and gas production begins.
Initial Results:
The tube was analyzed for Benzene, and the top nine other volatile organic compounds (VOCs) found.
Benzene was below the limits of detection, which is 3.9 ng for the tube. According to the lab, this limit would be equivalent to about 0.076 parts per billion (ppb), which is well below the 1.4 ppb long-term effects screening level, and the short-term 54 ppb ESL. Because benzene was not detected, we know that our levels are below 0.076 ppb.
Only three other compounds were detected, and none exceeded long term or short term effects screening levels (ESLs):
- 1R-.alpha.-Pinene at 0.15 ppb (Long term ESL is 1.0 ppb)
- Toluene at 0.03 ppb (Long term ESL is 330 ppb)
- m/p- Xylene at 0.02 ppb (Long term ESL is 42 ppb)
Toluene and Xylene are both solvents used in a variety of products, and part of the BTEX (Benzene, toluene, ethyl-benzene,xylene) quartet of hazardous chemicals that are sometimes emitted from natural gas operations.
According to an EPA fact sheet on Toluene, automobile emissions are the principal source of toluene emissions in ambient air. According to CDC, xylene is also found in automobile exhaust, and comes from industrial sources. The CPANA air sampling station for this test is located away from idling automobiles and well setback from nearby streets.
Pinene is a natural compound produced by pine trees, some of which surround the testing site.
Sampling Method
Samples are taken by using a diffusion tube exposed to the ambient air in a locked, ventilated box near the proposed drill site. Diffusion tubes are stainless steel tubes containing a sorbent material that passively soaks up air contaminants over a specified time period. The tubes are maintained with a strict chain of custody, installed under seal and witnessed by at least two CPANA board members. The completed sample is mailed to an analytical laboratory with no ties to any of the local natural gas operators.
The initial sample was taken from 6/23/2010 - 7/24/2010. Overall MOU (margin of uncertainty) is +/- 16.8%. The laboratory is certified for the analytical work, but ppb numbers take into account exposure times provided by CPANA, and for which they have no control.
Laboratory results are attached.
Wednesday, June 2, 2010
Message to CPANA Members and Community Stakeholders
In response to the concerns of our members, and recent news reports and investigations in our area regarding the impact of oil and gas development on air quality, the Board of Directors of the Central Park Area Neighbors Association is announcing CPANA’s intent to conduct air quality monitoring, beginning as soon as possible. Even though the wells slated for our neighborhoods are not yet even permitted, we feel it is important to obtain quality readings of our current air quality so that we have a valid base-line to compare with once the wells are drilled.
CPANA will utilize a professional analytical laboratory, which will provide sampling devices to trap air contaminants such as volatile organic compounds. Unlike some of the recent snapshot tests conducted by the state and some municipalities, we will be using a method that samples for 2 – 4 weeks, so that a good representative average can be obtained. Samples will be taken near the proposed drill site, and protocols will be used so that our members can have confidence in the results. We will sample each month, throughout all four seasons, using the prevailing wind data for each month as a basis for placement down wind from the proposed and eventual drill sites.
Each month, the laboratory will provide readings for benzene, plus the top nine other organic compounds found in the air – which may vary from month to month. CPANA will post its readings publicly for its members to review. Numbers will be given in comparison to long term effects screening levels (ESLs) as defined by TCEQ and other government agencies.
The CPANA Board feels that this modest expenditure will serve the community and encourage oil and gas operators in the area to use best practices to avoid polluting our air, as well as provide us with early warning if the gas operators should fall short.
Although we will not be able to disclose in advance all details of where and when we will be testing, in order to preserve the integrity of the test, we're happy to answer any questions that we can.
Please feel free to forward this email to your neighbors who may not be on our list. We will get back to you when we have our first results, and explain more as well as provide you with a web link where you can always find up-to-date results.
Subscribe to:
Posts (Atom)