What to look for when completing
an AWWA Water Audit for the first
time
Reinhard Sturm, Vice President
Water Systems Optimization, Inc.
Paul Johnson, Vice President
Water Systems Optimization, Inc.
03/14/2013
WaterRF 4372 – Project Background and Scope
11 participating utilities from NA
 Review of existing water loss regulations and
implementation experiences in NA
 Review of international best practices in
water loss regulation
 Develop utility tested model for component
analysis of real losses and evaluation of
economically feasible water loss intervention
strategies

WRF 4372 – Project Status and Findings
LATEST FINDINGS:
WORK COMPLETED:
•
North American average break
frequency literature review and
analysis
•
Quality and consistency of leak
repair data collection needs to be
improved
•
Review of select international water
loss guidelines and regulations
•
•
Review of national water audit
data sets
Even aggressive water loss
reporting regulations and
progressive guidelines underestimate data quality obstacles
•
Group of PU’s shows full range of
water loss control experience: both
exemplary utilities and those just
starting
•
Collection and review of water
audits and leak repair data from
participating utilities
•
Beta-testing of WaterRF software
tool
California – CUWCC BMP1.2
BACKGROUND:
BMP1.2 – Water Loss Control Program
(10years)

First four years focus on data validation and
water loss accounting

Second phase to establish benchmarks and
improvements to water loss performance

Six two-day workshops provided between
2010 and 2012 plus a webinar

WSO received the first data set of water
audits for data validation

California – CUWCC BMP1.2
2010 Water Data Analysis and Validation:

Simple steps of data validation were applied
Count
Percent of
Full Data Set
125
100%
Number of Utilities Reporting Negative Water Losses
5
4%
Number of Utilities Reporting ILI<1
36
29%
Number of Utilities Reporting ILI>20
3
2%
Number of Utilities Reporting Erroneous Infrastructure Data
1
1%
Final Data Set After Removal of Erroneous Water Audit Reports
80
64%
Number of Utilities Reporting Water Audit Result

Results highlight the problems utilities are facing when
completing an audit for the first time!
California – CUWCC BMP1.2
2010 Water Data Analysis and Validation:
36% report implausible results
Data Validity is an issue – more training and outreach needed
However:



Average data validity score 75.6 (Level IV = 71-90)
Average data validity score of utilities reporting negative water losses
77.0
51% of utilities report length for service pipe curb stop to meter
Financial data reported often questionable
Especially system input volume and consumption volumes need to
be validated

Note: Texas Water Audit Data showed similar data quality issues –
52% of water audits are technically impossible!!!!
California – CUWCC BMP1.2
15.00
California CUWCC BMP1.2 - Infrastructure Leakage Index (ILI) Reduced Data Set
14.00
13.00
12.00
11.00
10.00
8.00
7.00
6.00
5.00
4.00
3.00
2.00
1.00
83
81
79
77
75
73
71
69
67
65
63
61
59
57
55
53
51
49
47
45
43
41
39
37
35
33
31
29
27
25
23
21
19
17
15
13
9
11
7
0.00
5
ILI
9.00
Water Audit Data Validation
The Most Important Components
Water Audit Tasks – Critical Data Validation

Task: Challenge Accuracy of System Input
Meters
Volumetric Meter Test
Comparative Meter Test
Water Audit Tasks – Critical Data Validation

Task: Challenge Accuracy of System Input
Meters
Water Audit Tasks – Critical Data Validation

Task: Challenge Accuracy of System Input
Meters
Water Audit Tasks – Critical Data Validation

Task: Challenge Accuracy of System Input
Meters
:4
0
14 :06
:5
7
15 :2
:1 3
4
15 :39
:3
1
15 :56
:4
9
16 :1
:0 3
6
16 :30
:2
3
16 :47
:4
1
16 :0
:5 3
8
17 :20
:1
5
17 :37
:3
2
17 :5
:5 4
0
18 :11
:0
7
18 :2
:2 7
4
18 :44
:4
2
18 :01
:5
9
19 :1
:1 8
6
19 :35
:3
3
19 :51
:5
1
20 :0
:0 8
8
20 :25
:2
5
20 :42
:4
2
21 :5
:0 9
0
21 :15
:1
7
21 :3
:3 2
4
21 :49
:5
2
22 :06
:0
9
22 :2
:2 3
6
22 :39
:4
3
23 :56
:0
1
23 :1
:1 3
8
23 :30
:3
5
23 :47
:5
3
0: :03
10
:
0: 20
27
:
0: 37
44
:
1: 54
02
:
1: 11
19
:
1: 27
36
:
1: 44
54
:
2: 01
11
:1
8
MGD

14
Water Audit Tasks – Critical Data Validation
Task: Challenge SCADA Data Accuracy
Flow Rate (M G D)
10.5
=
[
( ( 4-20m A signal) - 4 )
16
Time
]*
M axim um Calibration
Flow -range (M G D)
Reservoir A raw water flowmeter data chain analysis
Comparison of converted 4-20 mA signal and SCADA reading
14
13.5
13
12.5
12
11.5
11
raw 4-20 mA signal from meter converted to MGD
10
SCADA value MGD
Water Audit Tasks – Critical Data Validation

Task: Validate Billing Data Accuracy
Water Audit Tasks – Critical Data Validation

Task: Validate Billing Data Accuracy
o
o
Second most
significant volume that
flows into AWWA
water balance
Two components:
•
•
Billed metered
consumption
Billed unmetered
consumption
o
Validation is crucial
Water Audit Tasks – Critical Data Validation

Task: Validate Billing Data Accuracy
Export of raw billing data (audit period plus 2 month on
each side)
 Typical billing data fields to be included:
→ Customer identification fields
→ Meter identification fields
→ Service type identification fields
→ Meter read and consumption fields – units
→ Trouble codes or flags

Water Audit Tasks – Critical Data Validation

Task: Validate Billing Data Accuracy

Confirm relevant consumption volumes:
•
Which accounts need to be included/excluded
•
Water and Sewer accounts
•
Sewer only accounts
•
AG accounts
•
Irrigation accounts
•
System meters
Water Audit Tasks – Critical Data Validation


Task: Validate Billing Data Accuracy
Validation of consumption volumes:
• Look for duplicates – meter numbers
– consumption volumes
•
Look for other irregularities:
- change of meter size
- number of estimates
- high consumption
- consecutive zero consumption
- etc.
Water Audit Tasks – Critical Data Validation
Task: Validate Billing Data Accuracy
Negative Monthly Consumption for Meter Size
Period July/05 to June/06
120,000
Blank
5/8
100,000
3/4
1
80,000
1 1/2
2
60,000
3
4
40,000
6
8
20,000
10
12
Month
Ju
ne
-0
6
ay
-0
6
M
06
Ap
ril
-
h06
ar
c
M
Ja
nu
ar
y06
Fe
br
ua
ry
-0
6
05
ec
em
be
r-
05
D
ov
em
be
r-
N
er
-0
5
O
ct
ob
m
be
r-0
5
5
S
ep
te
Au
gu
st
-0
-0
5
0
Ju
ly
Consumption (CCF)

Water Audit Tasks – Critical Data Validation

Task: Validate Billing Data Accuracy

Validation of consumption volumes:
Step 1 – deduct first read from last read for each meter
Step 2 – Sum consumption volume for each meter
Step 3 – compare results of Step 1 and Step 2 for each meter
Read_Date
2-Oct-06
4-Oct-06
29-Oct-07
1-Nov-07
29-Nov-07
27-Dec-07
29-Jan-08
27-Feb-08
28-Mar-08
Current_Read
159
162
0
0
162
162
165
166
167
Previous_Read
151
159
0
0
0
162
162
165
166
Read_Days
6
2
45
3
28
28
33
29
30
Usage
8
3
0
0
162
0
3
1
1
Water Audit Tasks – Critical Data Validation

Task: Validate Billing Data Accuracy

Lag-time Analysis – the simple way:
Water Audit Tasks – Critical Data Validation

Task: Validate Billing Data Accuracy

Lag-time Analysis – the simple way:
Water Audit Tasks – Critical Data Validation

Task: Validate Billing Data Accuracy
PREVIOUS
READING
DATE
07-Jun-07
CURRENT
READING
DATE
09-Jul-07
JUL-07
AUG-07
SEP-07
OCT-07
NOV-07
DEC-07
JAN-08
FEB-08
MAR-08
APR-08
MAY-08
JUN-08
TOTAL
Lag-time Analysis – PRORATING:
CONSUMPTION

50
14
0
0
0
0
0
0
0
0
0
0
0
14
09-Jul-07
07-Aug-07
0
0
0
0
0
0
0
0
0
0
0
0
0
0
07-Aug-07
06-Sep-07
105
0
84
21
0
0
0
0
0
0
0
0
0
105
06-Sep-07
04-Oct-07
45
0
0
39
6
0
0
0
0
0
0
0
0
45
04-Oct-07
05-Nov-07
78
0
0
0
66
12
0
0
0
0
0
0
0
78
05-Nov-07
07-Dec-07
38
0
0
0
0
30
8
0
0
0
0
0
0
38
06-Dec-07
08-Jan-08
0
0
0
0
0
0
0
0
0
0
0
0
0
0
08-Jan-08
07-Feb-08
0
0
0
0
0
0
0
0
0
0
0
0
0
0
07-Feb-08
07-Mar-08
2
0
0
0
0
0
0
0
2
0
0
0
0
2
07-Mar-08
07-Apr-08
72
0
0
0
0
0
0
0
0
56
16
0
0
72
07-Apr-08
06-May-08
19
0
0
0
0
0
0
0
0
0
15
4
0
19
06-May-08
06-Jun-08
216
0
0
0
0
0
0
0
0
0
0
174
42
216
06-Jun-08
08-Jul-08
56
0
0
0
0
0
0
0
0
0
0
0
42
42
681
14
84
60
72
42
8
0
2
56
31
178
84
631
TOTALS
Water Audit Tasks – Critical Data Validation

Task: Validate Billing Data Accuracy

Lag-time AnalysisProrated
– PRORATING:
Monthly Consumption Volume
City of Hayward - Calendar Year 2009
600
Billed Metered Consumption Volume (MG)
500
400
300
200
100
0
1
2
3
4
5
6
7
Month
8
9
10
11
12
Water Audit Tasks – Critical Data Validation

Task: Assess Customer Meter Accuracy
Meter size
Total volume supplied
through meters during
audit period (MG)
Average accuracy
based on meter
test results
Apparent Losses
during audit
period (MG)
5/8”
691.532
92.0%
59.725
3/4”
94.104
100.0%
-
1”
314.740
96.9%
10.136
1-1/2”
133.960
94.0%
8.535
2”
295.894
97.6%
7.214
Total
1,530.230
85.610
Water Audit – Things to Consider





Bring all the stakeholders together
Discuss current data collection and validation
efforts – get input from all departments
Have a water audit champion who collects all the
data and puts the audit together
Use the AWWA water audit data validation score
to assess current data validity and work on
improving data validity over time
Use the audit as a management tool to improve
financial viability of your utility
Thank You!
reinhard.sturm@wso.us
paul.johnson@wso.us