Tennessee Valley Authority
Kingston Ash Slide
Air Testing Results Summary
TVA is committed to ensuring the health and safety of the public and its employees. As part of that commitment, TVA has contracted with a third party to test the air around the Kingston Fossil Plant since shortly after the ash spill ( December 28, 2009), and testing will continue through the completion of the cleanup. To date, the more than 50,000 air samples taken by TVA confirm the Tennessee Department of Health finding that “The particulate matter and metals measured in air near the site are below national and state standards or are less than any levels of concern.” There is no indication of health concerns for area residents or workers.
Air testing is designed to answer two questions: How much dust is in the air? and What is in the dust? To answer the first question, we test for particulate concentration with either a hand-held or stationary monitor. To answer the second, we analyze the material found on air filters.
How Much Dust - Particulate Concentration?
TVA’s contractor Center for Toxicology and Environmental Health (CTEH) began monitoring with hand-held instruments on December 28, 2008. These instruments instantly measure the concentration of particles in the air. Typically 200-400 readings are collected every day with these instruments. These instruments measure the particulates smaller than 10 microns in size (PM10). This monitoring continues, and all daily averages have been well below the National Ambient Air Quality Standard for particulates of this size. View daily monitoring results
A temporary mobile laboratory was placed just south of the ash pond from Jan. 2 to Feb. 3, 2009. This laboratory measured particulates smaller than 2.5 microns, and particulates smaller than 10 microns. All daily total particulates measured were well below the 24-hr National Ambient Air Quality Standards.
View mobile laboratory results
During the initial ash spill response, CTEH also used temporary stationary monitors to collect samples 24-hours a day from five locations surrounding the ash spill area. CTEH has now transitioned to stationary long-term air monitoring, which will continue for the duration of ash recovery activities. Most of these monitors began collecting data on Feb. 12, 2009, and all of the new monitors were in operation by March 2009.
These monitors can measure particles smaller than 2.5 microns in diameter. They are similar to the size of particles in cigarette smoke. All measurements of particulates have been well below the 24-hour National Ambient Air Quality Standards.
What’s in it - Material Analysis?
The temporary stationary monitors used filters to collect samples over 24-hour periods from January 1 to March 11, 2009. These samples were analyzed for 21 metals, as well as quartz. Based on potential toxicity, eight metals were selected for reporting: arsenic, beryllium, cadmium, chromium, lead, selenium, thallium, and vanadium. . All of the concentrations were below the detection limits, except for one sample with a low concentration of cadmium and three samples with low concentrations of lead. These concentrations do not pose a health concern, since they are below the Agency for Toxic Substances and Disease Registry (ATSDR) acute minimal risk level for cadmium and below the National Ambient Air Quality Standard for lead.
View these sampling results
The temporary mobile laboratory also used filters to collect samples to be analyzed for metals. Samples were collected from Jan. 2 to Feb. 3, 2009. The samples were compared to background concentrations, or the amount of metals that are usually present in air. The samples showed that the airborne concentrations of all metals detected (arsenic, cadmium, chromium, lead, selenium, thallium and vanadium) on-site at Kingston were all within the lower end of the range of background concentrations in the United States. Background level information came from Toxicological Profiles by the U.S. Department of Health and Human Services, Agency for Toxic Substances and Disease Registry. Mobile Laboratory on-site monitoring was shut down on Feb. 4, 2009, because it was located on an area being prepared for on-site storage of ash. View mobile laboratory results
Replacing the temporary stationary monitors and the mobile laboratory, the new stationary long-term air monitors are located at the same five locations as the temporary stationary monitors. These monitors are more sensitive and the results show low concentrations of metals we could not detect before. This does not indicate an increase in air concentrations, but a better ability to measure lower concentrations. All metals results to date are in the low range of background levels for the United States.
The graph linked below compares the amount of arsenic measured in the air at Kingston versus the maximum concentration of arsenic measured in the air in Tennessee from 2005 to 2008 and the range of background concentrations found in the air in the U.S. This graph shows that concentrations of airborne arsenic at Kingston are at the low end of the range of typical background levels. View Graph
After more extensive analysis of metals in the ash and since the results during the initial monitoring phase have not indicated elevated levels of metals, filters from the new monitors will only be analyzed for arsenic and thallium. These two metals are the only ones in the ash that exceeded background concentrations in soil and/or Environmental Protection Agency (EPA) Regional Screening Levels for Chemical Contaminants in residential soil. Quartz will also continue to be monitored.
Because of the very low concentrations found in the initial sampling, the long-term monitors will be operated either every third day or every sixth day. This is similar to the Tennessee Department of Environment and Conservation’s and EPA’s air quality monitoring. View these results
TDEC is also conducting air monitoring at the site and EPA is auditing some of TVA’s monitors with co-located monitors. TDEC and TVA plan to operate their air quality monitors for the duration of the recovery activities.
Links
New Stationary Monitor Results
Daily Analytical Results Jan 1 through March 11
Mobile Laboratory Results (Below)
Air Monitoring and Dust Control Presentation to TN Air Pollution Control Board
On-Site 24-hr Average Fine Particles Data
The measurements below were obtained at TVA's mobile laboratory which operated on-site from Dec. 31 to Feb. 4. PM2.5 was measured with two different instruments: a TEOM monitor and a Federal Reference Method (FRM) sampler. The TEOM monitor measures PM2.5 continuously and records the hourly average concentration, while the FRM instrument contains a filter that collects airborne particles for 24-hours before it is sent to a laboratory for analysis. Filters in the sampler were changed at noon each day.
The graph linked below shows the 24-hr average fine particle (PM2.5) concentrations measured by the TEOM monitor. These hourly readings were averaged from midnight-to-midnight to calculate the 24-hour value. All measurements are well below the National Ambient Air Quality Standard of 35 micrograms per cubic meter.
24-hr Average Concentrations (PDF, 57 kb)
In order to compare the TEOM measurements with those from the FRM sampler, we averaged the hourly TEOM data from noon-to-noon each day and graphed the data using the sampling start date. These measurements are also well below the National Ambient Air Quality Standard of 35 micrograms per cubic meter.
24-hr PM2.5 – Comparing TEOM and FRM Instruments
Daily measured concentrations of metals on-site at Kingston are compared to typical background levels in rural and urban areas. Tables of the analytical data show that all concentrations are at or below background levels and below levels of concern.
Maximum recorded values of metals during the period are compared with typical background levels in rural and urban areas.
Concentrations of all samples which were above detection limits are shown in graphical form below. Airborne concentrations of arsenic, cadmium, chromium, lead, selenium, thallium and vanadium on-site at Kingston were all within the lower end of the range of background concentrations in the United States.
View Metals Concentration Chart
This on-site monitoring was shut down on Feb. 4, 2009, because the area it was based on was being prepared for on-site storage of dredged ash.
Page Updated August 10, 2009 8:35 AM