Just how many mercury thermostats are there in Oklahoma?

Thermostat Recycling Corporation (TRC) is a voluntary program established by the largest manufacturers of thermostats to collect and recycle old mercury-added thermostats. The program has had varying degrees of success across the country, but as the numbers below show these initiatives have not yet had a significant impact in Oklahoma. In 2008 TRC collected in Oklahoma: 248 mercury thermostats & 169 bulbs or 1.0478 lbs of mercury. That means in 2008 TRC collected: .00006726 thermostats per capita[1]

There is not yet a commonly accepted methodology for calculating the number of thermostats available for collection, but we do have some guidelines for estimating how many thermostats are coming “off the walls” annually on a per capita basis.[2] Below is the actual amount collected by TRC compared to two different calculations of the total available for collection (i.e., the estimated number of thermostats coming off of walls in Oklahoma).

A story in numbers:

Thermostats collected in 2008 in OK / 248
Thermostats available collection
(low estimate) / 50,113.5 [3]
Thermostats available for collection
(high estimate) / 71,096[4]
Lbs of mercury collected in 2008 in OK by TRC / 1.0478
Lbs of mercury contained in thermostats available for collection
(low estimate) / 330.749[5]
Lbs of mercury contained in thermostats available for collection
(high estimate) / 426.58 lbs annually

[1] According to the US census OK population is: 3,687,050

[2] PSI is currently researching a more accurate way to calculate what is available.

[3] According to methodology developed by Skumatz Economic Research Associates on behalf of the Thermostat Recycling Corporation (data from the US census) : 1.2 thermostats/residence * 1,637,138 housing units =1,964,565.6 / 11.7 years (avg. life span in residential setting) = 167,911.59 annually5.6 thermostats/business *91,235 (private non-farm establishments) = 510,916 /15.7 years (avg life span) = 32,542.42 available annually

[4]According to methodology developed by the Maine Department of Environmental Protection: (data from US census): 1.5 thermostats per home x 1,637,138 housing units = 2,455,707; 1.25 thermostats per business x 91,235 (private non-farm establishments) = 114,043.75

Total = 2,569,750.75 (83% of all thermostats considered to be mercury) = 2,132,893.12 mercury thermostats available for collection/ 30 (average lifespan of a thermostat) = 71,096.43 (annually); Thermostats x 3 grams per stat = 6,398,679.36 grams of mercury (or 12,797.35 lbs) / 30 = 426.58 lbs annually

[5] Total thermostats available annually = 200,454.01 all thermostats available annually. Taking a conservative estimate that 25% of those are mercury that would mean 50,113.5 are available for collection annually x 3 grams = 150,340.5 grams of mercury (330.749 lbs)