City of Guelph
Guelph Residential Greywater Field
Test Draft Final Report
Appendix B
Water Savings Monitoring Data
Final Report
June 29, 2012
1
Water Savings Monitoring Data
Each of these charts represents a ‘snap shot’ in time for a different participating home. In each
chart you can identify the flush volume of the toilets in the home and the addition of potable
water. Note that in some cases there are multiple flushes during the 15-minute monitoring
period, for example – in Chart #1 the toilet flush volume is 6L yet there are ‘events’ of 12L,
30L,36L, and 48L, all multiples of 6L. Chart #2 indicates that the home is fitted with a very
inefficient 18-L per flush toilet. The toilet flush volume in Chart#3 is 8L, likely indicating that the
home has installed a 6L toilet that is flushing with a greater volume than it should. Chart #4
illustrates that the home has a dual-flush toilet and a potentially malfunctioning potable water
makeup valve (52 litres of makeup water was added in a single event).
Potable Water vs. Greywater Supply 6L Flush Volume
70
Toilet flush volume = 6L
Often more than one 6L flush during 15-minute monitoring cycle
Multiple toilet flushes followed by addition of potable water
60
40
30
20
10
Potable Water Supply
23:00
22:00
21:00
Greywater Supply
Figure 1: 6L Flush Volumes
2
20:00
19:00
18:00
17:00
16:00
15:00
14:00
13:00
0
12:00
Litres per Event
50
Potable Water vs. Greywater Supply 18L Flush Volume
40
Toilet flush volume = 18L
Two flushes during 15-minute monitoring cycle at 10:00
a.m.
High flush volume results in need to add potable water
35
Litres per Event
30
25
20
15
10
5
0.75
0.71
0.67
0.73
0.69
0.67
0.65
0.63
0.60
0.58
0.56
0.65
Potable Water Supply
0.54
0.52
0.50
0.48
0.46
0.44
0.42
0.40
0.38
0.35
0.33
0.31
0
Greywater Supply
Figure 2: 18L flush Volume
Potable Water vs. Greywater Supply 8L Flush Volume
16
14
Toilet flush volume = 8L
15 L of potable water added after multiple toilet
flushes
10
8
6
4
2
Potable Water Supply
0.71
0.69
0.63
0.60
0.58
0.56
Greywater Supply
Figure 3: 8L Flush Volume
3
0.54
0.52
0.50
0.48
0.46
0.44
0.42
0.40
0.38
0.35
0.33
0.31
0.29
0.27
0
0.25
Litres per Event
12
Potable Water vs. Greywater Supply Dual-Flush 4L/6L Flush
Volumes
60
Dual-Flush Toilet, flush volumes
= approximately 6 and 4L
Approx. 52 L of potable water
added at 12:45 pm (high volume
may indicate malfunctioning
potable water refill valve)
40
30
20
10
Potable Water Supply
Greywater Supply
Figure 4: Dual-Flush (4&6 L Flush Volumes)
4
0.71
0.69
0.67
0.65
0.63
0.60
0.58
0.56
0.54
0.52
0.50
0.48
0.46
0.44
0.42
0.40
0.38
0.35
0.33
0.31
0.29
0.27
0
0.25
Litres per Event
50