Re: Gelman - drilling results
Roger Rayle
Those darn boulders!
Boulders or not, Pall should be required to drill and sample all the way to bedrock. Why? The 400+ ppb is way outside where Pall maps showed that high of concentration and contrary to the trends depicted on their recent maps, which showed that not even the 85ppb boundary extended that far south and west. Plus the presence of dioxane above non-detect for all samples from 50-170 feet deep show that this is not just a single seam of dioxane. There might significant concentrations deeper than the current deepest sample of 68ppb at 170 feet deep.
This is not Pall/Gelman property. This is University of Michigan property ... and apparently moving in a direction not predicted by Pall's simplistic modeling. It's 500-100 feet away from any other concentration that high. This could be very bad news for wells south and west of Saginaw Forest... and maybe eventually for the City of Ann Arbor's Steere Farm well field near the airport where the City gets 20% of its water.
It could be another Unit E fiasco. Maybe this is where the 4000-5000ppb at TW-4 went. Or maybe its where the 30000ppb at MW-37 went.
Also, this delayed finding is another example why the proposed Part 201 rule changes to allow polluters to prematurely terminate cleanup operations could transfer huge costs and risks to the public.
This news needs to go out the the general mailing list... not just the CARD Tech group.
--Roger--
Roger Rayle
Vice-Chair, SRSW
www.srsw.org
This note is to update the technical group on the drilling activities at the U of M Saginaw Forest Caretaker's cabin and drilling currently underway at the south end of Parkland Plaza.
They started drilling south of Third Sister Lake on August 25, about 45 feet west of MW-78. At about 40 feet they hit a boulder and could not go deeper. They grouted that hole and moved about 5 feet west. On Aug. 26 they had drilled to about 160 feet. On Aug. 27 they drilled until about 172 feet when they hit another boulder. They continued drilling on Aug. 30 to about 180 feet but were unable to advance the Simulprobe out the end of the augers to collect a sample. The boulder caused the augers to deflect at an angle which prevented additional groundwater and soil sampling. Upon retrieval of the auger string, several augers were bent, and the drill bit worn smooth and could not go deeper. The drill bit was worn and the shaft bent. DNRE staff was on site for much of the drilling on Aug. 25 & 26, when they had reached about 170 feet, and also on the afternoon of Aug. 30.
Vertical profile results were available on Monday morning, Aug. 30, and are provided below, along with a summary of the lithology. PLS, their consultants and DNRE staff discussed the findings that afternoon. It was agreed that installing a shallow well in the current boring was not advisable due to the need to grout the hole below where the well would be screened. On Aug. 31 they moved about 10 feet east and installed MW-125, screened between 65 and 70 feet.
PLS and the drillers did not want to drill to bedrock at that location due to the conditions at 170 feet, which were also encountered during previous borings. Access for the drill rig is difficult due to the surrounding wooded area. A suitable location was found about 750 feet WSW and U of M approved installation of a boring at that location. After additional discussion it was decided to delay the boring at that location until after results are obtained from MW-125 next week.
Saginaw Forest boring:
0-6' silty sand, dry
6-9' sand, moist
9-15' sandy silt, moist
15-32' sand and gravel, wet; samples at 20' - ND & 30' - ND
32-42' diamicton (Silt)
42-72' sand and gravel (interbedded silt seams from approx. 60 to 70'); samples at 50' - 45 ppb & 60' - 439 ppb & 70' - 461 ppb
72-112' diamicton (Silt)
112-120' sand and gravel; sample at 120' - 31 ppb
120-123' diamicton (Silt)
123-172' sand, gravel, cobbles; samples at 130' - 28 ppb & 140' - 16 ppb & 150' - 20 ppb & 160' - 66 ppb & 170' - 68 ppb
172' Boulder. Drilled hard to 175', then drilled easier to 180' (unable to collect 180' sample).The drilling has moved to the condo area near the south end of Parkland Plaza, where two separate well nests are to be installed. They are currently drilling near MW-20 and have encountered the following conditions. Vertical profile samples are being collected at ten foot intervals in water bearing units and results should be available next week.
0-9' Sand and Gravel, dry
9-19' Sandy Silt, dry
19-46' Sand, wet at 30'
46-53' Diamicton (Silt), dry
53-93' Sand, wet
93-129' Diamicton (Silt), dry
129-130' Silty Sand, moist
130-135' Diamicton (Silt), dry
135-143' Sand and Gravel, wet
143-174' Diamicton (Cobbles from 164 to 174'), dryThey hit another boulder at 174 feet and could not advance further. They are moving over a short distance to attempt to reach bedrock at that location.
We will keep you informed as we receive new information.
Sybil Kolon
Senior Environmental Quality Analyst
Remediation Division
Department of Natural Resources and Environment
301 E. Louis Glick Hwy.
Jackson, MI 49201
phone: 517-780-7937
fax: 517-780-7855
e-mail: kol...@michigan.gov