A guide to water testing in developing countries using a Portable Microbiology Laboratory, and how to pasteurize contaminated water using sunshine and a simple solar cooker.
Album by Bob Metcalf. Photos by Bob Metcalf. 1 - 132 of 132 Total. 12265 Visits.
1 Water - Safe to Drink? Nepal
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6 Mwamongu Village water source, Tanzania
7 Water source in Dar es Salaam, Tanzania
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9 The presence of the bacterium Escherichia coli indicates recent fecal contamination of water.
10 Water tests should provide this information
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14 Components of the Portable Microbiology Laboratory with Colilert and Petrifilm tests for E. coli
15 Old, inexact methods on the left, to be replaced by modern tests for E. coli, right
16 Portable Microbiology Lab with materials for 25 Colilert & Petrifilm tests
17 Prof. Metcalf holds the two Portable Microbiology Laboratory tests: Colilert MPN tube, and E. coli count Petrifilm.
18 Colilert: A presence/absence test for E. coli in bottles or tubes
19 Colilert for 100 ml, left, and 10 ml, tubes on right.
20 Colilert is an approved water testing method in 40 countries
21 ONPG and MUG are the two substates for E. coli in Colilert
22 How to use Colilert MPN. Collect water in sterile WhirlPak (open well in Temeke Municipality, Dar es Salaam, Tanzania)
23 Carefully remove cap from Colilert tube
24 Use sterile pipette to add 10 ml of water source
25 Carefully replace cap
26 Shake tube to dissolve chemicals
27 Incubate tubes at 35°C for next day results
28 Tubes can also be incubated next to one's body to obtain next day results.
29 Body incubation of Colilert tubes
30 Next day Rresults Clear = no coliform bacteria. Yellow (ONPG+) = coliform bacteria present, possibly E. coli
31 Use a battery-operated long UV light to shine on tubes. Blue fluorescence = MUG +, E. coli is present, water not safe to drink.
32 The best test for E. coli in foods: E. coli Count Petrifilm
33 Two substrates in Petrifilm for E. coli, lactose and BCIG
34 To use Petrifilm, label sample source and time
35 Use sterile pipette to collect exactly 1 ml of water
36 Raise the edge of film to expose nutrient circle
37 Add 1 ml of water sample to nutrient circle
38 Carefully roll down film onto nutrient circle
39 Use flat side of plastic spreader to gently distribute 1 ml over entire circle
40 Petrifilms ready for incubation
41 Petriflms covered with firm cardboard enables incubation on one's body, ~20 doublings for invisible bacteria to develop into visible colonies
42 Results usually in 10-18 hr. E. coli = blue colonies with gas. Coliforms besides E. coli = red with gas.
43 Petrifilm & Colilert tests correlate with risk of disease, WHO Guidelines for Drinking Water Quality, 2nd Edition.
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45 UN Habitat Water Testing Booklet, November, 2010
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47 Ready to start workshop. Boniphace translates for Prof. Metcalf
48 Two water sources in Saka Saka. From a pump (green bucket) and an open stream (yellow bucket).
49 Adults will sample either pump or stream water
50 Mixing inoculated Colilert tubes, to incubate overnight
51 Petrifilms also inoculated by either pump or stream water
52 Next day demonstration of solar cooking, solar water pasteurization
53 Next day results: Pump water yellow, MUG -, no E. coli. Stream yellow and MUG+, E. coli present.
54 Examining Petrifilms the next morning
55 Next day Petrifilm results are clear.
56 Stream water (front) with ~100 E. coli colonies on each Petrifilm, very high disease risk. Pump water with coliform bacteria, but not E. coli, low disease risk.
57 All villagers see results of grossly contaminated stream water, no E. coli contamination of pump water.
58 Solar cooked rice in 2 hr
59 Providing a year's supply of water testing materials to Saka Saka health workers
60 Solar water pasteurization and cooking demonstrated in Saka Saka. This could be replicated in villages worldwide.
61 Water testing/solar pasteurization workshop for Village Chiefs and Village Health workers, Meatu District, Tanzania, 2001
62 Village health workers examine results the following day
63 Village chief knows that MUG+ Colilert means that E. coli was in the town's river water source, unsafe water
64 Health worker finds >10 E. coli on Petrifilm, town river source poses a very high risk of disease
65 Boniphace explaining Petrifilm results of village water sources Meatu
66 Workshop participants given Colilert tubes to test home water sources, Nyakach, Kenya, 2003
67 Colilert tubes incubated overnight in Nyakach
68 All home water sources ONPG +, contain coliform bacteria
69 All water sources from shallow wells also contain E. coli
70 Collecting Nyakach shallow well water for testing
71 Results of Nyakach shallow well - > 10 E. coli/ml very high risk of disease
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74 Students at California State University, Sacramento, who contributed to water pasteurization work
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76 Water Pasteurization article, 1984
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78 Water Pasteurization Indicator (WAPI). When water reaches 65°C (149°F), wax melts and falls to the bottom. Water is pasteurized.
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81 Use a Cookit solar cooker. 5 liters pasteurized in 3 hours of sunshine
82 Article on Cookit and WAPI to pasteurize water, 1999
83 Water vendor collecting river water, Mwanhuzi town, Meatu District, Tanzania, 2000
84 Water vendors try to sell water in Mwanhuzi
85 Guest House (hotel)
86 River water provided for guests
87 After testing river water, collect for solar pasteurization
88 Heating river water in Cookit
89 Temperature >60°C in 2 hours
90 WAPI wax melted, water is pasteurized
91 Ready to test pasteurized water
92 Micro tests before (top) and after solar pasteurization
93 Solar cooking & solar water pasteurization in Nyakach, Kenya
94 Solar cook in Nyakach with WAPI
95 Africa Women and Water Conference, Nairobi, July, 2008
96 Water testing session
97 Inoculating Petrifilms and Colilert tubes with water from their home areas
98 Next day results of Nigeria water
99 Examining Petrifilm results
100 Prof. Metcalf shows 2004 Nobel Peace Prize winner Prof. Wangari Maathai Colilert test results
101 And Petrifilm results
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103 In Bondo, Kenya, With Laban Onongno, UN-Habitat Chief Technical Advisor, Lake Victoria Wat/San Program
104 Prof. Metcalf leads workshop for Bondo community, December, 2008
105 Inoculating Colilert test with 10 ml of Bondo drinking water source
106 Petrifilm test of Bondo drinking water source
107 Next day results in Bondo
108 Now we're microbiologists!
109 Results from nine Bondo water drinking water sources
110 PML methods taught in Bondo by Gobei Secondary School teacher Tobias Amolo, July, 2009
111 Prof. Metcalf presents PML materials to Mr. Amolo, July, 2009
112 Class results of local water sources before and after WaterGuard treatment.
113 Test results before and after chlorination of water source
114 UN-Habitat workshop in Kisumu, Kenya, July, 2010
115 UN-Habitat water testing workshop, Harar, Ethiopia, November, 2010
116 Harar certificate
117 World Water Week, Stockholm, Sweden, August 20-26, 2011
118 UN-Habitat booth. Demonstrating water testing.
119 Portable Microbiology Laboratory for World Vision, Ghana
120 Prof. Metcalf and UN Habitat's Lars Stordal at Rwanda workshop location
121 Each workshop participant received a mini-PML, materials for 10 water test, and a WAPI
122 Integrated Health Program, Democratic Republic of the Congo
123 Workshop participants, Lodja, DRC
124 Second day results
125 Demonstrating solar water pasteurization
126 With Dinah Chienjo (left)and Faustine Odaba at IWA Development Congress, Kenya, 2013
127 International Water and Health Alliances booth
128 Delegate inoculates Colilert. Water testing made easy with the PML.
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130 International Water and Health Alliances booth in Jordan
131 American Society for Microbiology workshop, New Orleans
132 American Society for Microbiology workshop participants
