Ensuring safe drinking water for those without!
Leo Lawrenson
Rotary Club of Buford/North Gwinnett
For children in developing countries,
each year contaminated water causes:
2 million deaths
1.5 billion episodes of diarrhea
The Microbiology of Solar Water Pasteurization,
with Applications in East Africa
Robert Metcalf
Professor, Biological Sciences
California State University, Sacramento
Background Facts
 Pasteurization kills microorganisms that cause disease
 Pasteurization occurs at (or below) 65 ⁰ C/149⁰F
What is a WAPI?
 Invented by Fred Barrett and Dale Andreatta
 WAPI is a simple thermometer
 Polycarbonate tube containing wax
 Wax melts at or above pasteurization temperature
 Indicates when heated liquid has been pasteurized
 Eliminates need to boil water or milk
 Saves fuel
 Reusable
How do you use a WAPI?
How do you use a WAPI?
How do you make a WAPI?
 Materials List:
 Polycarbonate tubing (3/8” OD, ¼” ID)
 Wax (Myverol 18-06)
 Washer (18-8ss, 3/8” ID, 1”OD)
 Stainless steel wire cable (20#, 14” length)
 2 Single Barrel Compression Sleeves
 Wire “S” Hook (3” annealed wire)
 Press-to-seal Bag (3”x4” or larger)
 Instruction sheet
Station 1
Cut tubing into
lengths of 2 1/2”.
Use PVC pipe
cutters.
Station 2
Using a small
propane torch,
heat one tube end
and crimp closed
with pair of pliers
and let cool.
Station 3
Put wax inside
tube (about 3/8” of
wax) and add large
washer over noncrimped end.
Station 4
Using the propane
torch, heat
opposite end of
tube and crimp
closed using pliers.
Let cool.
Station 5
Drill 1/32”
diameter hole in
each flattened end
of tube.
Station 6
Cut stainless steel
wire cable into 14”
lengths. Insert one
end of the wire into a
compression sleeve.
Bend the cable end
around and insert in
the compression
sleeve from the
opposite end
forming a loop.
Using pliers,
compress the sleeve
to hold the loop of
wire firmly .
Station 7
Thread the wire
through one end of
the tube, up along
the side of tube,
under the large
washer, and
through the hole at
the opposite end of
the tube. Form a
loop using the
other end of the
wire and a
compression
sleeve.
Station 8
Test by hanging in
170⁰+ water, check
that wax melts,
and no leaks.
Station 9
Dry unit and insert
into plastic snack
bag along with "S"
hook and
Instruction on
"How to Use.“
SHIP ‘EM!
The Bottom Line:
WAPIs are a critically important
international service project!
Ensuring safe drinking water for those without!
Leo Lawrenson
Rotary Club of Buford/North Gwinnett