Post date: Sep 01, 2014 4:49:22 AM
April 17, 2002
New Dioxane Finds in City
SRSW received well logs for the new monitoring wells (MW-76s, MW-76i, MW-76d, located at Jackson & Worden, east of the fire station.
The surface elevation there is about 927'.
The well logs show the following dioxane sample results at various depths (03/25/02):
59 ppb @ ~ 80 ft
72 ppb @ ~ 100 ft
53 ppb @ ~ 120 ft
33 ppb @ ~ 140 ft
35 ppb @ ~ 170 ft
<diamicton/silt layer at 196-217 ft>
15 ppb @ ~ 190 ft
16 ppb @ ~ 200 ft
10 ppb @ ~ 240 ft
12 ppb @ ~ 260 ft
<shale encountered at 273 ft> (no dioxane sample)
The highest concentrations are at an elevation 807-847, well above the E unit. How it got there without being detected earlier is a new mystery.
It's also bad news that the E unit shows 12-16 ppb over some 70 foot thickness there.
MW-72 near where I-94 crosses Jackson Road is now up to 2370 ppb.
The city supply well at Montgomery remains closed with latest readings still at 2 ppb.