Questions and Answers
Which substance will give the higher score for waste characeristics and why?
The second gives the higher score (1,000), because no value is lost to the cap of 108. The first substance loses two orders of magnitude to the cap and gives a score of 320. This happens only when hazardous waste quantity is at its maximum value of 1,000,000.
Turtles are trapped for soup in the wetland. Is this a fishery?
What value would you assign for food chain individual if you have an area of actual contamination on a small to moderate stream and cannot document that anyone ever fishes there? The area might, for instance, be very small, on private property, fenced, or relatively inaccessible compared to other nearby fishing locations. You can, however, document that the river a mile downstream is a fishery and that people fish within the mouth of the stream.
20. Based on the third bullet. If it were not for this bullet, you would have to consider the mouth of the stream the nearest fishery and multiply by 20 for potential, times a dilution weight of 0.1 for a small to moderate stream.
Scenario A: Production is 40 pounds per acre per year, a nice value for a stocked fishery. The river is about 40 feet wide and has a stream flow of 200 cfs. The fishery is 15 miles long and is exposed to potential contamination. What is the value for potential population? (Note that 40 feet x 15 miles x 5280 feet/mile / 43,560 ft2 per acre = about 73 acres.)
0.003. Annual production is about 2920 pounds (73 x40) and gives a population value of 3 from HRS Table 4-18, page 51621. The dilution weight from HRS Table 4-13, page 51613 is 0.01.
- 3 (population) x 0.01 (dilution) x 1/10 (potential) = 0.003
- Note in this exercise that the pounds per acre of annual production can vary in a rather large range before it makes any difference in the resulting value for potential population.
Scenario B: What is the potential population value if the fishery is a minimal perennial stream with a production that is either unknown or less than 100 pounds?
- 0.003. Annual production is "greater than 0 to 100 pounds" and gives a population value of 0.03 from HRS Table 4-18, page 51621.
- The dilution weight from HRS Table 4-13, page 51613 is 1.
- 0.03 (population) x 1 (dilution) x 1/10 (potential) = 0.003