Post date: Sep 01, 2014 4:20:21 AM
December 14, 2000
Here is some more news from the Pall-Gelman November 2000 report packet:
REVISED 5-YEAR PLAN STILL HAS MAJOR FLAWS.
The packet includes two revisions of Pall-Gelman's "5-year plan" to meet the court's deadline. One of these revisions includes a calculation of the amount of mass of 1,4-dioxane that will have to be removed to get the Core, Evergreen, and Western plumes under 85 ppb in 5 years.
They estimate that there is 25,938 pounds of 1,4-dioxane in 806,414,647 gallons of groundwater. But this does not include the Soils area, the Marshy area, the Spray Irrigation area, the Burn Pit area, nor any other shallow aquifer areas. It also does not include areas where the concentration is currently below 85 ppb, nor does it include any newly discovered or yet to be discovered areas such as that near MW-56 west of the Saginaw Forest and south of Little Lake, which had readings of 500 ppb.
The 25,938 pounds (about 3110 gallons) of 1,4-dioxane in 806,414,647 gallons of groundwater gives an average dioxane level of 3874 ppb for the limited area being analyzed. But the current average concentration being purged is only around 3000 ppb and dropping, which means that a lot of dioxane will be left after five years unless the higher areas of 1,4-dioxane can be found and purged.
The 3874 average ppb is 45 times the current drinking water standard of 85 ppb and about 1300 times the pre-1995 standard of 3 ppb.
The 5-year plan assumes a uniform mass of 1,4-dioxane purged each month over the 5-year period with a constant purge rate, which is clearly an unreasonable assumption. Either many more purge wells or impossibly high purge rates are going to have be used or a lot of dioxane will be left in the groundwater after five years.
(More to come when space allows)