Unit Conversion Exercises For Emission Inventories

Please work your answers on a separate sheet of paper.

Unit Conversions and Math

  1. To determine the emissions from burn barrels on your reservation, the open burning TEISS calculator asks for the tons of waste burned during your inventory year. Through surveys, you estimate that 982 pounds of waste were burned that year. What is the value you need to enter into the TEISS calculator?
  1. Your tribe is going to build a museum and cultural center to attract tourists. It will have its own access road loop off the highway. You need to know how many vehicle miles traveled (VMT) will be caused by the extra traffic from people visiting the center. You know that 1 VMT = 1 vehicle traveling a distance of 1 mile. It is estimated that 5,000 cars a year will visit the center. You measure the new access road loop with a walking wheel and find it is 3,960 feet long.
  2. If 1 car travels 0.5 miles, how many VMT is that?
  1. How many miles long is the access road loop?
  1. What is the estimated annual VMT for cars visiting the center?
  1. To determine how much VOC is emitted by gas stations on your reservation, the TEISS calculator tells you to enter the fuel throughput in units of 103 gallons, in other words, thousand gallons. There are three gas stations on your reservation and you collect data on the volume of gasoline sold at each of these three stations.

Gas Station 1: 5,000 gallons

Gas Station 2: 20,000 gallons

Gas Station 3: 1,900 liters

You entered this source as a nonpoint source, therefore you need to sum the volumes to come up with the total volume to enter into the TEISS calculator. What value should you enter as the fuel throughput?

Energy Unit Conversions

  1. To determine emissions from natural gas combustion on your reservation, you call the local gas company and ask how much gas was sold to both residential and commercial accounts in your inventory year. Here is what they tell you (your contact at the gas company doesn’t know how many BTUs their gas has per cubic foot):
  2. Annual Residential sales = 345,854 therms
  3. Annual Commercial sales = 287,156 therms

Residential and commercial natural gas combustion emissions should be calculated separately, due to how EPA accounts for emissions. You look at the TEISS calculator for natural gas combustion and it asks for MMscf (million standard cubic feet). Note: scf is the common notation used in the natural gas industry for cubic feet(ft3)of natural gas at standard temperature and pressure.

  1. What is a therm? (Google it!)
  1. Convert both sales amounts into BTUs.
  1. The EPA AP-42 default for natural gas energy density is 1020 BTUs/scf. Convert both sales amounts into scf.
  1. Convert both sales amounts in MMscf
  1. Open the TEISS calculator for Residential Woodstove Combustion. Notice how the data entry area changes when you change the “Units” from US standard to US cords. The emission factors for wood combustion are given in lbs/ton wood burned. What extra conversion is TEISS doing for you when you enter cords (which is a volume of wood, not a weight.) In other words, if you have a volume of wood and you want to know how much it weighs, what property of the wood do you need to know?