Drinking Water Scheme
Summary of Results External Quality Assessment of Water Microbiology
Drinking Water Scheme Distribution Number: W174
Sample Numbers: W174A, W174B, W174C
Distribution Date: Results Due: Report Date:
March 2017 14 April 2017 25 April 2017
Samples prepared and quality control tested by:
Angela Appea Richard Borrill Thomas Harper Zak Prior Judith Spellar Aneta Stranc Lili Tsegaye
Data analysed by:
Manchari Rajkumar Nita Patel
Report compiled by:
Manchari Rajkumar Nita Patel
Authorised by:
Nita Patel
This report must not be reproduced without permission of the organisers. Public Health England Food and Environmental Proficiency Testing Unit (FEPTU) 61 Colindale Avenue London NW9 5EQ Tel: +44 (0)20 8327 7119 Fax: +44 (0)20 8200 8264 Email: [email protected] The data in FEPTU reports is confidential
Page 1 of 29
Printed at 7:42 on Wednesday, 26 April, 2017
For further information on the scheme please refer to: Scheme Guide: https://www.gov.uk/government/publications/food-and-water-proficiency-testing-schemes-scheme-guide Guide to Scoring and Statistics: https://www.gov.uk/government/publications/food-and-water-proficiency-testing-schemes-scoring-systems-and-statistics
General guidance for z-scores: Participants' enumeration results are converted into z-scores using the following formula:
Z = (xi-Xpt) σpt
xi Xpt
= participants' result expressed (expressed as a log 10 value) = assigned value (participants' consensus median (expressed as a log 10 value))
σpt
= the fixed standard deviation for the examination (calculated by FEPTU)
The σpt-value expresses the acceptable difference between the individual participant 's result and the participants' consensus median. The σpt-value used for calculating z-scores for all parameters in the Drinking Water Scheme is 0.35. A guide to interpreting z-scores follows, although laboratories must interpret their scores in the context of their own laboratory situation. z = -1.99 to +1.99 z = -2 to -2.99 or +2 to +2.99 z= < -3.00 or > + 3.00
satisfactory questionable unsatisfactory
It is usually recommended that z-scores exceeding +/-2 are investigated to establish the possible cause. rule, PHE recommends that all questionable and unsatisfactory results are investigated.
As a general
FEPTU Quality Control: To demonstrate homogeneity of the sample, a minimum of 10 LENTICULE® discs, selected randomly from a batch, are tested in duplicate for parameters requiring enumeration.
To demonstrate stability of the sample, a minimum of nine LENTICULE discs, selected randomly from a batch, are examined throughout the distribution period for enumeration parameters. PHE uses methods stipulated in the DWI 's series of documents: The Microbiology of Drinking Water (2002) - Methods for the Examination of Waters and Associated Materials. The FEPTU results are used for guidance in the preliminary intended results notification, letters are posted on the website immediately after every distribution; electronic notification of their availability is sent to all participants. Refer to section 17.0 of the Scheme Guide if you have experienced difficulties with any of the examinations . https://www.gov.uk/government/publications/food-and-water-proficiency-testing-schemes-scheme-guide
Participants are reminded that reporting an incorrect or false negative results could have serious public health implications. Participants who report unexpectedly high or low results for enumerations on single occasions only should not be unduly alarmed, although they should still assess the reason(s) for the outlying result. The results, as summarised in the performance assessment sheet included in this report, provide a more effective indication of on-going problems with the enumeration of low levels of indicator organisms in drinking water samples. Performance assessment cannot be undertaken as effectively if laboratories do not participate in all distributions for the Drinking Water Scheme.
Please contact FEPTU staff for advice and information: Repeat samples
Carmen Gomes or Kermin Daruwalla
Data Analysis
Manchari Rajkumar or Nita Patel
Microbiological advice
Nita Patel or Zak Prior
General comments and complaints
Nita Patel or Zak Prior
Scheme consultants
Julie E. Russell
Scheme Co-ordinator
Nita Patel
Tel: Fax: Email:
+44 (0)20 8327 7119 +44 (0)20 8200 8264 [email protected]
FEPTU's website
Accreditation: PHE Water EQA Scheme for Drinking Water is accredited by the United Kingdom Accreditation Service (UKAS) to ISO/IEC 17043:2010.
0006 The data in FEPTU reports is confidential
Page 2 of 29
Printed at 7:42 on Wednesday, 26 April, 2017
Sample: W174A Contents:
Klebsiella pneumoniae 16 (wild strain), Escherichia coli 10 (wild strain), Clostridium perfringens 66 (wild strain), Kocuria kristinae 1.2x10² (NCTC 11038)
Expected Results: All counts are expressed as colony forming units (cfu) per 100mL except the colony counts at 37ºC/48h and 22ºC/72h which are cfu per mL.
Colony count 22ºC/72h
Colony count 37ºC/48h
C.perfringens
P.aeruginosa
26
10
0
0
66
121
124
No. results returned
125
131
114
96
92
115
110
Assigned value
27
11
0
0
70
120
116
Uncertainty of assigned value*
0.04
0.03
N/A
N/A
0.02
0.01
0.01
Participants mean (all results)
25
11
0
0
67
119
115
8 - 84
1 - 35
N/A
N/A
22 - 221
38 - 379
37 - 365
0.34
0.32
N/A
N/A
0.16
0.09
0.09
No of outlying counts
23
11
N/A
N/A
5
7
7
False positives
N/A
N/A
0
3
N/A
N/A
N/A
False negatives
2
2
N/A
N/A
1
1
0
E.coli
FEPTU median
Parameter
Enterococci
Coliform bacteria
The fixed standard deviation value (σpt value) used for calculation of the z-scores is 0.35 for all parameters.
(Participants median all results)
Expected Range
Standard deviation** ( log₁₀)
Your result
Score for performance assessment
Z-score
Analyst 2 Result
Analyst 2 Z-score
Analyst 3 Result
Analyst 3 Z-score
*
U(Xpt) is based on results transformed to a log₁₀ scale
**
Robust S* based on median absolute deviation about the participants' median (MADe) and is based on logged data
Total sent samples
144
Not examined
5
Non returns
8
Late returns
0
The data in FEPTU reports is confidential
Page 3 of 29
Printed at 7:42 on Wednesday, 26 April, 2017
Sample: W174B Contents:
Klebsiella oxytoca 6 (wild strain), Escherichia coli 17 (wild strain), Pseudomonas aeruginosa 37 (wild strain), Staphylococcus xylosus 3 (NCIMB 13636)
Expected Results: All counts are expressed as colony forming units (cfu) per 100mL except the colony counts at 37ºC/48h and 22ºC/72h which are cfu per mL.
Colony count 37ºC/48h
Colony count 22ºC/72h
17
0
37
0
3
3
No. results returned
125
130
114
94
94
114
109
Assigned value
25
20
0
22
0
2
2
Uncertainty of assigned value*
0.03
0.03
N/A
0.04
N/A
0.05
0.05
Participants mean (all results)
24
19
0
23
0
3
3
8 - 79
6 - 63
N/A
7 - 70
N/A
0-6
0-8
0.27
0.27
N/A
0.29
N/A
0.33
0.36
No of outlying counts
22
20
N/A
15
N/A
11
11
False positives
N/A
N/A
1
N/A
2
N/A
N/A
False negatives
2
2
N/A
4
N/A
0
0
E.coli
Parameter
P.aeruginosa
23
Enterococci
FEPTU median
Coliform bacteria
C.perfringens
The fixed standard deviation value (σpt value) used for calculation of the z-scores is 0.35 for all parameters.
(Participants median all results)
Expected Range
Standard deviation** ( log₁₀)
Your result
Score for performance assessment
Z-score
Analyst 2 Result
Analyst 2 Z-score
Analyst 3 Result
Analyst 3 Z-score
*
U(Xpt) is based on results transformed to a log₁₀ scale
**
Robust S* based on median absolute deviation about the participants' median (MADe) and is based on logged data
Total sent samples
144
Not examined
6
Non returns
8
Late returns
0
The data in FEPTU reports is confidential
Page 4 of 29
Printed at 7:42 on Wednesday, 26 April, 2017
Sample: W174C Contents:
Enterococcus faecalis 36 (wild strain), Pseudomonas aeruginosa 70 (wild strain), Clostridium perfringens 48 (wild strain), Staphylococcus epidermidis 5 (wild strain)
Expected Results: All counts are expressed as colony forming units (cfu) per 100mL except the colony counts at 37ºC/48h and 22ºC/72h which are cfu per mL.
Colony count 37ºC/48h
Colony count 22ºC/72h
70
48
5
2
126
132
115
97
93
116
112
0
0
49
55
55
5
1
Uncertainty of assigned value*
N/A
N/A
0.01
0.02
0.02
0.04
0.05
Participants mean (all results)
0
0
48
54
52
5
0
Expected Range
N/A
N/A
15 - 153
17 - 174
17 - 174
1 - 16
0-5
Standard deviation**
N/A
N/A
0.1
0.18
0.19
0.33
0.45
N/A
N/A
10
6
6
9
10
False positives
3
1
N/A
N/A
N/A
N/A
N/A
False negatives
N/A
N/A
1
4
0
0
0
No. results returned
Assigned value
C.perfringens
36
P.aeruginosa
0
FEPTU median
Enterococci
E.coli
0
Parameter
Coliform bacteria
The fixed standard deviation value (σpt value) used for calculation of the z-scores is 0.35 for all parameters.
(Participants median all results)
( log₁₀) No of outlying counts
Your result
Score for performance assessment
Z-score
Analyst 2 Result
Analyst 2 Z-score
Analyst 3 Result
Analyst 3 Z-score
*
U(Xpt) is based on results transformed to a log₁₀ scale
**
Robust S* based on median absolute deviation about the participants' median (MADe) and is based on logged data
Total sent samples
144
Not examined
4
Non returns
8
Late returns
0
The data in FEPTU reports is confidential
Page 5 of 29
Printed at 7:42 on Wednesday, 26 April, 2017
27 Participant Median 26 FEPTU Median
0
Outlying results
Outlying results
5-7
25
1
2
>106
Outlying results
30
Outlying results
1
PHE score
84-106
0
106
84-106
75-84
70-74
65-69
60-64
55-59
50-54
45-49
40-44
36-39
32-35
28-31
24-27
20-23
16-19
12-15
0
8-11
No. of Results
25
Outlying results
30
45
11 Participant Median 10 FEPTU Median
0
Outlying results
25
1
2
Outlying results
30
35-45
PHE score
No. of Results
20
15
10
5
32-35
30-31
28-29
26-27
24-25
22-23
20-21
18-19
16-17
14-15
12-13
10-11
8-9
6-7
4-5
3-3
45
35-45
32-35
30-31
28-29
26-27
24-25
22-23
20-21
18-19
16-17
14-15
12-13
10-11
8-9
6-7
4-5
3-3
1-2
0
221
200-221
189-199
178-188
167-177
156-166
145-155
134-144
123-133
113-122
103-112
93-102
83-92
73-82
63-72
53-62
43-52
33-42
221
200-221
189-199
178-188
167-177
156-166
145-155
Count per 100mL TSC (Membrane Filtration)
134-144
123-133
113-122
103-112
93-102
83-92
73-82
63-72
53-62
43-52
33-42
22-32
0
379
344-379
326-343
308-325
290-307
272-289
254-271
236-253
218-235
200-217
182-199
164-181
146-163
128-145
110-127
92-109
74-91
56-73
38-55
379
344-379
326-343
308-325
290-307
272-289
254-271
Count per mL
236-253
218-235
200-217
182-199
164-181
146-163
128-145
110-127
92-109
74-91
56-73
38-55
0
365
330-365
312-329
294-311
276-293
259-275
242-258
225-241
208-224
191-207
174-190
157-173
140-156
123-139
106-122
89-105
72-88
55-71
37-54
365
330-365
312-329
294-311
276-293
259-275
242-258
Count per mL
225-241
208-224
191-207
174-190
157-173
140-156
123-139
106-122
89-105
72-88
55-71
37-54
0
100
Outlying results
30
Outlying results
1
PHE score
79-100
0
100
79-100
70-79
65-69
60-64
56-59
52-55
48-51
44-47
40-43
36-39
32-35
28-31
24-27
20-23
16-19
12-15
0
8-11
No. of Results
25
Outlying results
30
78
Outlying results
30
Outlying results
1
PHE score
63-78
0
78
63-78
56-63
52-55
48-51
44-47
40-43
37-39
34-36
31-33
28-30
25-27
22-24
19-21
16-18
13-15
10-12
0
6-9
No. of Results
25
Outlying results
30
76
22 Participant Median 37 FEPTU Median
0
Outlying results
2
70-76
1
Outlying results
No. of Results
25
0
6-6
30
Outlying results
PHE score
76
70-76
63-70
59-62
55-58
51-54
47-50
43-46
39-42
35-38
31-34
27-30
23-26
19-22
16-18
13-15
10-12
0
7-9
No. of Results
25
Outlying results
30
153
138-153
130-137
122-129
114-121
106-113
99-105
92-98
85-91
78-84
71-77
64-70
57-63
50-56
43-49
36-42
29-35
22-28
153
138-153
130-137
122-129
114-121
106-113
Count per 100mL
99-105
92-98
85-91
78-84
71-77
64-70
57-63
50-56
43-49
36-42
29-35
22-28
15-21
0
174
157-174
148-156
139-147
130-138
121-129
113-120
105-112
97-104
89-96
81-88
73-80
65-72
57-64
49-56
41-48
33-40
25-32
174
157-174
148-156
139-147
130-138
121-129
113-120
Count per 100mL Pseudalert (MPN)
105-112
97-104
89-96
81-88
73-80
65-72
57-64
49-56
41-48
33-40
25-32
17-24
0
174
157-174
148-156
139-147
130-138
121-129
112-120
Count per 100mL TSC (Membrane Filtration)
103-111
94-102
85-93
76-84
67-75
59-66
51-58
43-50
35-42
27-34
0
17-26
No. of Results
25
Outlying results
30
Drinking Water Scheme Distribution Number: W174
Sample Numbers: W174A, W174B, W174C
Distribution Date: Results Due: Report Date:
March 2017 14 April 2017 25 April 2017
Samples prepared and quality control tested by:
Angela Appea Richard Borrill Thomas Harper Zak Prior Judith Spellar Aneta Stranc Lili Tsegaye
Data analysed by:
Manchari Rajkumar Nita Patel
Report compiled by:
Manchari Rajkumar Nita Patel
Authorised by:
Nita Patel
This report must not be reproduced without permission of the organisers. Public Health England Food and Environmental Proficiency Testing Unit (FEPTU) 61 Colindale Avenue London NW9 5EQ Tel: +44 (0)20 8327 7119 Fax: +44 (0)20 8200 8264 Email: [email protected] The data in FEPTU reports is confidential
Page 1 of 29
Printed at 7:42 on Wednesday, 26 April, 2017
For further information on the scheme please refer to: Scheme Guide: https://www.gov.uk/government/publications/food-and-water-proficiency-testing-schemes-scheme-guide Guide to Scoring and Statistics: https://www.gov.uk/government/publications/food-and-water-proficiency-testing-schemes-scoring-systems-and-statistics
General guidance for z-scores: Participants' enumeration results are converted into z-scores using the following formula:
Z = (xi-Xpt) σpt
xi Xpt
= participants' result expressed (expressed as a log 10 value) = assigned value (participants' consensus median (expressed as a log 10 value))
σpt
= the fixed standard deviation for the examination (calculated by FEPTU)
The σpt-value expresses the acceptable difference between the individual participant 's result and the participants' consensus median. The σpt-value used for calculating z-scores for all parameters in the Drinking Water Scheme is 0.35. A guide to interpreting z-scores follows, although laboratories must interpret their scores in the context of their own laboratory situation. z = -1.99 to +1.99 z = -2 to -2.99 or +2 to +2.99 z= < -3.00 or > + 3.00
satisfactory questionable unsatisfactory
It is usually recommended that z-scores exceeding +/-2 are investigated to establish the possible cause. rule, PHE recommends that all questionable and unsatisfactory results are investigated.
As a general
FEPTU Quality Control: To demonstrate homogeneity of the sample, a minimum of 10 LENTICULE® discs, selected randomly from a batch, are tested in duplicate for parameters requiring enumeration.
To demonstrate stability of the sample, a minimum of nine LENTICULE discs, selected randomly from a batch, are examined throughout the distribution period for enumeration parameters. PHE uses methods stipulated in the DWI 's series of documents: The Microbiology of Drinking Water (2002) - Methods for the Examination of Waters and Associated Materials. The FEPTU results are used for guidance in the preliminary intended results notification, letters are posted on the website immediately after every distribution; electronic notification of their availability is sent to all participants. Refer to section 17.0 of the Scheme Guide if you have experienced difficulties with any of the examinations . https://www.gov.uk/government/publications/food-and-water-proficiency-testing-schemes-scheme-guide
Participants are reminded that reporting an incorrect or false negative results could have serious public health implications. Participants who report unexpectedly high or low results for enumerations on single occasions only should not be unduly alarmed, although they should still assess the reason(s) for the outlying result. The results, as summarised in the performance assessment sheet included in this report, provide a more effective indication of on-going problems with the enumeration of low levels of indicator organisms in drinking water samples. Performance assessment cannot be undertaken as effectively if laboratories do not participate in all distributions for the Drinking Water Scheme.
Please contact FEPTU staff for advice and information: Repeat samples
Carmen Gomes or Kermin Daruwalla
Data Analysis
Manchari Rajkumar or Nita Patel
Microbiological advice
Nita Patel or Zak Prior
General comments and complaints
Nita Patel or Zak Prior
Scheme consultants
Julie E. Russell
Scheme Co-ordinator
Nita Patel
Tel: Fax: Email:
+44 (0)20 8327 7119 +44 (0)20 8200 8264 [email protected]
FEPTU's website
Accreditation: PHE Water EQA Scheme for Drinking Water is accredited by the United Kingdom Accreditation Service (UKAS) to ISO/IEC 17043:2010.
0006 The data in FEPTU reports is confidential
Page 2 of 29
Printed at 7:42 on Wednesday, 26 April, 2017
Sample: W174A Contents:
Klebsiella pneumoniae 16 (wild strain), Escherichia coli 10 (wild strain), Clostridium perfringens 66 (wild strain), Kocuria kristinae 1.2x10² (NCTC 11038)
Expected Results: All counts are expressed as colony forming units (cfu) per 100mL except the colony counts at 37ºC/48h and 22ºC/72h which are cfu per mL.
Colony count 22ºC/72h
Colony count 37ºC/48h
C.perfringens
P.aeruginosa
26
10
0
0
66
121
124
No. results returned
125
131
114
96
92
115
110
Assigned value
27
11
0
0
70
120
116
Uncertainty of assigned value*
0.04
0.03
N/A
N/A
0.02
0.01
0.01
Participants mean (all results)
25
11
0
0
67
119
115
8 - 84
1 - 35
N/A
N/A
22 - 221
38 - 379
37 - 365
0.34
0.32
N/A
N/A
0.16
0.09
0.09
No of outlying counts
23
11
N/A
N/A
5
7
7
False positives
N/A
N/A
0
3
N/A
N/A
N/A
False negatives
2
2
N/A
N/A
1
1
0
E.coli
FEPTU median
Parameter
Enterococci
Coliform bacteria
The fixed standard deviation value (σpt value) used for calculation of the z-scores is 0.35 for all parameters.
(Participants median all results)
Expected Range
Standard deviation** ( log₁₀)
Your result
Score for performance assessment
Z-score
Analyst 2 Result
Analyst 2 Z-score
Analyst 3 Result
Analyst 3 Z-score
*
U(Xpt) is based on results transformed to a log₁₀ scale
**
Robust S* based on median absolute deviation about the participants' median (MADe) and is based on logged data
Total sent samples
144
Not examined
5
Non returns
8
Late returns
0
The data in FEPTU reports is confidential
Page 3 of 29
Printed at 7:42 on Wednesday, 26 April, 2017
Sample: W174B Contents:
Klebsiella oxytoca 6 (wild strain), Escherichia coli 17 (wild strain), Pseudomonas aeruginosa 37 (wild strain), Staphylococcus xylosus 3 (NCIMB 13636)
Expected Results: All counts are expressed as colony forming units (cfu) per 100mL except the colony counts at 37ºC/48h and 22ºC/72h which are cfu per mL.
Colony count 37ºC/48h
Colony count 22ºC/72h
17
0
37
0
3
3
No. results returned
125
130
114
94
94
114
109
Assigned value
25
20
0
22
0
2
2
Uncertainty of assigned value*
0.03
0.03
N/A
0.04
N/A
0.05
0.05
Participants mean (all results)
24
19
0
23
0
3
3
8 - 79
6 - 63
N/A
7 - 70
N/A
0-6
0-8
0.27
0.27
N/A
0.29
N/A
0.33
0.36
No of outlying counts
22
20
N/A
15
N/A
11
11
False positives
N/A
N/A
1
N/A
2
N/A
N/A
False negatives
2
2
N/A
4
N/A
0
0
E.coli
Parameter
P.aeruginosa
23
Enterococci
FEPTU median
Coliform bacteria
C.perfringens
The fixed standard deviation value (σpt value) used for calculation of the z-scores is 0.35 for all parameters.
(Participants median all results)
Expected Range
Standard deviation** ( log₁₀)
Your result
Score for performance assessment
Z-score
Analyst 2 Result
Analyst 2 Z-score
Analyst 3 Result
Analyst 3 Z-score
*
U(Xpt) is based on results transformed to a log₁₀ scale
**
Robust S* based on median absolute deviation about the participants' median (MADe) and is based on logged data
Total sent samples
144
Not examined
6
Non returns
8
Late returns
0
The data in FEPTU reports is confidential
Page 4 of 29
Printed at 7:42 on Wednesday, 26 April, 2017
Sample: W174C Contents:
Enterococcus faecalis 36 (wild strain), Pseudomonas aeruginosa 70 (wild strain), Clostridium perfringens 48 (wild strain), Staphylococcus epidermidis 5 (wild strain)
Expected Results: All counts are expressed as colony forming units (cfu) per 100mL except the colony counts at 37ºC/48h and 22ºC/72h which are cfu per mL.
Colony count 37ºC/48h
Colony count 22ºC/72h
70
48
5
2
126
132
115
97
93
116
112
0
0
49
55
55
5
1
Uncertainty of assigned value*
N/A
N/A
0.01
0.02
0.02
0.04
0.05
Participants mean (all results)
0
0
48
54
52
5
0
Expected Range
N/A
N/A
15 - 153
17 - 174
17 - 174
1 - 16
0-5
Standard deviation**
N/A
N/A
0.1
0.18
0.19
0.33
0.45
N/A
N/A
10
6
6
9
10
False positives
3
1
N/A
N/A
N/A
N/A
N/A
False negatives
N/A
N/A
1
4
0
0
0
No. results returned
Assigned value
C.perfringens
36
P.aeruginosa
0
FEPTU median
Enterococci
E.coli
0
Parameter
Coliform bacteria
The fixed standard deviation value (σpt value) used for calculation of the z-scores is 0.35 for all parameters.
(Participants median all results)
( log₁₀) No of outlying counts
Your result
Score for performance assessment
Z-score
Analyst 2 Result
Analyst 2 Z-score
Analyst 3 Result
Analyst 3 Z-score
*
U(Xpt) is based on results transformed to a log₁₀ scale
**
Robust S* based on median absolute deviation about the participants' median (MADe) and is based on logged data
Total sent samples
144
Not examined
4
Non returns
8
Late returns
0
The data in FEPTU reports is confidential
Page 5 of 29
Printed at 7:42 on Wednesday, 26 April, 2017
27 Participant Median 26 FEPTU Median
0
Outlying results
Outlying results
5-7
25
1
2
>106
Outlying results
30
Outlying results
1
PHE score
84-106
0
106
84-106
75-84
70-74
65-69
60-64
55-59
50-54
45-49
40-44
36-39
32-35
28-31
24-27
20-23
16-19
12-15
0
8-11
No. of Results
25
Outlying results
30
45
11 Participant Median 10 FEPTU Median
0
Outlying results
25
1
2
Outlying results
30
35-45
PHE score
No. of Results
20
15
10
5
32-35
30-31
28-29
26-27
24-25
22-23
20-21
18-19
16-17
14-15
12-13
10-11
8-9
6-7
4-5
3-3
45
35-45
32-35
30-31
28-29
26-27
24-25
22-23
20-21
18-19
16-17
14-15
12-13
10-11
8-9
6-7
4-5
3-3
1-2
0
221
200-221
189-199
178-188
167-177
156-166
145-155
134-144
123-133
113-122
103-112
93-102
83-92
73-82
63-72
53-62
43-52
33-42
221
200-221
189-199
178-188
167-177
156-166
145-155
Count per 100mL TSC (Membrane Filtration)
134-144
123-133
113-122
103-112
93-102
83-92
73-82
63-72
53-62
43-52
33-42
22-32
0
379
344-379
326-343
308-325
290-307
272-289
254-271
236-253
218-235
200-217
182-199
164-181
146-163
128-145
110-127
92-109
74-91
56-73
38-55
379
344-379
326-343
308-325
290-307
272-289
254-271
Count per mL
236-253
218-235
200-217
182-199
164-181
146-163
128-145
110-127
92-109
74-91
56-73
38-55
0
365
330-365
312-329
294-311
276-293
259-275
242-258
225-241
208-224
191-207
174-190
157-173
140-156
123-139
106-122
89-105
72-88
55-71
37-54
365
330-365
312-329
294-311
276-293
259-275
242-258
Count per mL
225-241
208-224
191-207
174-190
157-173
140-156
123-139
106-122
89-105
72-88
55-71
37-54
0
100
Outlying results
30
Outlying results
1
PHE score
79-100
0
100
79-100
70-79
65-69
60-64
56-59
52-55
48-51
44-47
40-43
36-39
32-35
28-31
24-27
20-23
16-19
12-15
0
8-11
No. of Results
25
Outlying results
30
78
Outlying results
30
Outlying results
1
PHE score
63-78
0
78
63-78
56-63
52-55
48-51
44-47
40-43
37-39
34-36
31-33
28-30
25-27
22-24
19-21
16-18
13-15
10-12
0
6-9
No. of Results
25
Outlying results
30
76
22 Participant Median 37 FEPTU Median
0
Outlying results
2
70-76
1
Outlying results
No. of Results
25
0
6-6
30
Outlying results
PHE score
76
70-76
63-70
59-62
55-58
51-54
47-50
43-46
39-42
35-38
31-34
27-30
23-26
19-22
16-18
13-15
10-12
0
7-9
No. of Results
25
Outlying results
30
153
138-153
130-137
122-129
114-121
106-113
99-105
92-98
85-91
78-84
71-77
64-70
57-63
50-56
43-49
36-42
29-35
22-28
153
138-153
130-137
122-129
114-121
106-113
Count per 100mL
99-105
92-98
85-91
78-84
71-77
64-70
57-63
50-56
43-49
36-42
29-35
22-28
15-21
0
174
157-174
148-156
139-147
130-138
121-129
113-120
105-112
97-104
89-96
81-88
73-80
65-72
57-64
49-56
41-48
33-40
25-32
174
157-174
148-156
139-147
130-138
121-129
113-120
Count per 100mL Pseudalert (MPN)
105-112
97-104
89-96
81-88
73-80
65-72
57-64
49-56
41-48
33-40
25-32
17-24
0
174
157-174
148-156
139-147
130-138
121-129
112-120
Count per 100mL TSC (Membrane Filtration)
103-111
94-102
85-93
76-84
67-75
59-66
51-58
43-50
35-42
27-34
0
17-26
No. of Results
25
Outlying results
30
