Student activity sheet
Making decisions about TCE Name__________________________
Period: 1 2 3 4 5 6 7
Read each scenario. All are about real situations. Then, discuss with your group what your decision would be. Base your decision on knowledge you’ve gained in this unit. Record your decision and the facts that support it. Be prepared to share your decision with the class at the end of the period.
Scenario 1- The Parker Pen Co.
The Parker Pen Co. is a major manufacturer of pens, mechanical pencils, pencil sharpeners, and related items. They use TCE vapor degreasers throughout the plant to clean oils from metal pen caps, barrels, buttons and refill parts. They had been using 25 drums of TCE per month. They want to reduce that amount.
Scenario 2- Rio de Janeiro Manufacturing
Ricardo Brakarz is manager of the plant. It produces aluminum caps for cosmetic bottles and tubes. They use TCE to degrease the caps. Cosmetic companies will only purchase clean caps. Ricardo writes to a help website: “I am trying to decide if tetrachloroethylene can be used instead of TCE in a vapor degreaser. Our company is very concerned about environmental issues.” Several other users of TCE wrote back:
Response #1 “Switching to tetrachloroethylene will cost you more and is harder on the equipment. It also does not clean aluminum as well as TCE. You should just seal you system better so fumes don’t release and continue with TCE.”
Response #2 “Have you considered using a water/detergent wash instead? We made the switch a few years ago. It cleans well, and eliminates the hazardous waste issue.”
Response #3 “We have found that a new cleaner called Detride works well and is rated non-hazardous.”
Scenario 3- Ford Motor Co.
The Ford Motor Co. previously used TCE vapor degreasers extensively. They are in the process of replacing all TCE with water/detergent wash systems. One plant in Indiana reduced their release of TCE by 50,000 pounds per year.
Scenario #4- Jostens’s in Princeton, Il
If the name sounds familiar, that’s because this is the company that makes class rings, memory books, graduation announcements, caps and gowns, etc. They use TCE by the tanker truck load (90,000 pounds TCE per year). Up until 1976, Josten’s poured their used TCE in a pond on their property and allowed it to “disappear”, which was the recommended treatment at that time.
In 1982 and again in 1984 the chemical delivery company spilled TCE on the ground during deliveries.
In 1994, TCE contamination was detected in the groundwater below Josten’s and a neighboring property. Josten’s had spent $6 million to clean up the waste pond and the spills.
Scenario #5- Army base in Fort Riley, KS
“Decades” ago, “large” quantities of TCE were spilled on the base. The area was paved over with asphalt, which created an anaerobic situation, hindering microbial breakdown. In 2004, sampling showed TCE concentrations up to 28,000 ppb.
The army removed the asphalt and “stirred in” KMnO4 and water into the top 10 feet of soil.
Three weeks later, testing showed a TCE concentration of 2100 ppb. A nearby well had a TCE concentration of 95 ppb. The army predicts that the TCE will reach acceptable levels in five more years.
Fort Riley saved $4.5 million by using this method over others proposed.