The data and information provided has been collected by automated monitors and has not been subjected to a quality assurance review to determine accuracy. The application of quality assurance and verification procedures to the data and information may result in differences between what is currently provided and what will become the official record. Additionally, due to quality assurance, the data may be amended, without notice, at any time. At this time, the data is provided as a "public service" on an "as is" basis without warranty, whether express or implied, as to its quality, accuracy, suitability, reliability, usability, completeness, timeliness, or applicability for particular purposes.
Basic- information and reliability
The data presented on the LDEQ webpage represents collected samples that were sent to a laboratory for analysis. The results have been reviewed and validated. Non-Continuous data includes PM2.5, lead, and canister samples. The sample time for all samples, with the exception of “Grab” samples, reflect the start time of the sample in Central Standard Time (CST). Grab sample times reflect the start of the sample in local time.
PM 2.5 and lead samples are 24-hour samples. Samples are collected in varied sequences (every day, 3, 6, 12 days). Canister samples are collected in varying durations; including, 24-hour, 3-hour, 0.42-hour (25-minute), and Grab samples of about 7 – 10 seconds. An annual average may be calculated by averaging the results from 24-hour samples taken once every six days for a period of one year.
Canister samples may be 24-hour samples that begin and end at midnight. Alternatively, 25-minute “strike” samples are triggered when the non-methane hydrocarbons (NMHC) maintains a pre-determined value (usually 1.0 ppmC) for a period of 10 minutes. Twenty-four-hour samples may be used to calculate an annual average. Three-hour samples are typical of Photochemical Assessment Monitoring Sites (PAMS) and are used for looking at volatile organic hydrocarbons (VOCs) at different times of the day. 0.42-hour (25-minute) strike samples are taken at some sites when the non-methane organic carbon (NMOC) concentration remains at or above a predetermined value (typically 1.0 ppmC) for a period of ten minutes. These are looking for increased concentrations and should not be included when calculating an annual average. “Grab” samples are instantaneous samples that only provide a brief snapshot of the current conditions at a particular place and time. These, too, are generally acquired due to upset conditions and are not included when calculating an annual average.
Limitations of information
The Department makes every effort to assert the validity and integrity of the data, but data can be affected by equipment malfunctions, technical difficulties, and other unforeseen circumstances. All air monitoring equipment, including continuous instruments, is subject to intermittent fluctuations, or spikes, which can cause invalid readings. The equipment may be disrupted for periodic maintenance and quality checks as well as power failures and instrument malfunctions. Local environmental conditions can vary widely across the region and may also have an impact on the air quality measurements and the subsequent data. Additionally, due to quality assurance, the data may be amended, without notice, at any time. The data may be revised or invalidated after review.
Limiting liability of the agency
The LDEQ has exercised all reasonable skill and care in compiling the contents of this information and under no circumstances will the LDEQ or its agents be liable in contract, tort, or otherwise for any loss, injury, or damage arising directly or indirectly from the supply of this data. At this time, the data is provided as a "public service" on an "as is" basis without warranty, whether express or implied, as to its quality, accuracy, suitability, reliability, usability, completeness, timeliness, or applicability for particular purposes. However, all validated data is complete and accurate for all pollutants to the best of our knowledge, taking into consideration the quality assurance findings. Use of LDEQ’s air quality monitoring data is at the user’s discretion and should be done with caution.