screen development is being done.
The graded bentonite does not allow the
mixed bentonite grout to migrate into
the pack.
I'll discuss some tips on mixing neat
cement and get more into the specifics
of bentonite-based grouts in my next
column. I'll also cover grout standards
in an upcoming column too.
WWJ
WWJ September 2016 47
Twitter @WaterWellJournl
DACUM Codes
To help meet your professional needs,
this column covers skills and competen-
cies found in DACUM charts for drillers
and pump installers. DO refers to the
drilling chart. The letter and number
immediately following is the skill on
the chart covered by the column. This
column covers:
DOB-1, DOB-4, DOE-16
More information on DACUM and the
charts are available at
www.NGWA.org.
Gary Shawver, MGWC, is president of Shawver Well Co. Inc., an employee stock ownership plan
company in Fredericksburg, Iowa. He has been in the water well industry for 40 years and is a
Master Groundwater Contractor. He has served as president of the Iowa Water Well Association,
the Iowa Groundwater Association, and most recently served on the NGWA Board of Directors.
Shawver is semi-retired, having recently sold his business to his employees. He contributes to
NGWA's member e-publication and can be reached at grs@shawverwell.com.
