HomeMy WebLinkAbout19 Consumption Study Agenda Item # 19
TRUCKEE DONNER
TuUbl�ic Utility District
WORKSHOP
To: Board of Directors
From: Neil Kaufman
Date: April 01, 2009
Subject: Preliminary Data from Residential Customer Consumption Study
1. WHY THIS MATTER IS BEFORE THE BOARD
This item is informational.
2. HISTORY
AB 2572 requires that the District begin reading the water meters installed since 1992
and commence billing on a volumetric basis by January 1, 2010. AB 2572 also
requires that all connections be equipped with water meters and billed on a volumetric
basis by January 1, 2025.
In the Fall of 2008, the District awarded a contract to MCS for the provision of an
automated meter reading (AMR) system and the installation of water meters as part of
a pilot program. The purpose of the pilot program is to:
1) Verify that the selected system will function in Truckee given the local climate
and construction practices.
2) Gather data on residential water consumption to be used in developing volume-
based water rates.
The system provided by MCS utilizes water meters manufactured by Neptune and
radios manufactured by Aclara.
3. NEW INFORMATION
MCS has completed the installation of all meters and meter mounted radios
associated with the pilot program. There are a total of 409 meters in this pilot
program.
Prior to issuing the RFP for the automated meter reading system, the Water
Department was conducting a pilot utilizing ten water meters manufactured by Badger
and radios manufactured by Datamatic. At the recommendation of former Board
President Tim Taylor, this pilot was continued and expanded to include an additional
20 meters.
TECHNOLOGY TESTING
Prior to 2008, the District's standard construction practices called for the use of cast
iron lids on residential meter boxes. It has been determined that these metal lids
cause significant interference with the radio signals and change out of these lids from
metal to plastic is necessary to optimize performance of the AMR system. One
example involves a residence in on Moraine Road at Donner Lake where radio signals
had not been received since February 17. On March 18, the meter box lid was
changed from metal to plastic. Since that time, hourly reads have been received from
that radio. As of March 23, there were 35 radios that were not communicating.
Replacement of meter box lids at these locations should solve the problem. Similar
issues were experienced with the Datamatic radios whereby replacement of the meter
box lids markedly improved radio performance.
The original cost estimates for the water meter implementation assumed that about
one third of the meter box lids would require replacement. It is likely that more meter
box lids will require replacement, with an associated increase in cost to the District.
As noted above, there are 409 water meters configured with the Aclara radio system.
Of this total, 112 are Badger meters with Badger registers and 297 are Neptune
meters with Neptune registers. With the Neptune/Aclara system, the automated leak
detection capabilities are located within the Neptune meter register and not the radio.
Therefore, the Badger meters do not have this capability.
The Neptune leak detection algorithm divides a 24-hour period in 96 15-minute blocks.
It then looks to see if flow occurred during some or all of those 15-minute blocks. The
leak detection algorithm does not look at the magnitude of flow, it only examines
whether or not flow occurred. An intermittent leak is flagged if flow occurs in more
than 50 of the 96 blocks. A constant leak is flagged if flow occurs in all of the 96
blocks. The default leak reporting functions in the management software do not
display this information in a clear manner. The District is working with Aclara to make
this information easier to access.
WATER CONSUMPTION DATA COLLECTION
As of January 15, 2009, all of the pilot program radios were installed and functioning.
Water consumption data was then reviewed for all pilot locations for the period of
January 15, 2009 to March 24, 2009. As noted above, meter reads are not being
received from some units. After change out of all meter box lids has been completed,
these meters should be reporting and more accurate data should be available. Therefore,
the water consumption data discussed below should be considered preliminary.
• Average winter water consumption is 182 gallons per day (gpd). For
comparison, the average winter water production was about 253 gpd and the
overall annual average water production was about 800 gpd per residential
customer for calendar 2008.
• Larger than expected usage was found at a number of accounts. There were
19 accounts with usage above 500 gpd and nine of those exceeded 1,000 gpd.
Such high volumes are unexpected considering that there is no irrigation
occurring at this time of year. The largest usage was over 8,700 gpd. A District
field crew field verified this high usage and contacted the property owner.
There appears to be an underground leak on the customer-owned service
lateral or irrigation system at that address.
On March 25, 47 of the 297 Neptune meters were registering a constant leak.
75 percent of those residences were built in the 1980s or earlier.
Approximately 50 meters were registering an intermittent leak.
28 of the 33 largest water users (based on average gpd) are registering a constant
leak. The other five are equipped with Badger meters without automatic leak
detection capability. It is assumed that those users also have a constant leak.
The highest average usage is occurring in the Sierra Meadows area (265 gpd)
with the lowest average usage in the Martiswoods (121 gpd), Pine Forest (119
gpd) and Prosser Lakeview (120 gpd) areas.
To date, it appears that average water usage is not influenced by house size
but is more likely a function of number of occupants and whether those
occupants are full-time or part-time.
The highest average usage is occurring at houses constructed in the 1970s and
1980s at about 270 gpd.
The average usage of full-time accounts is 198 gpd. The average usage of
part-time accounts is 72 gpd.
4. FISCAL IMPACT
There is no direct fiscal impact associated with this workshop. The information
gathered during the pilot program will be used to refine the District's costs associated
with Phases 2 and 3 of the Water Meter Implementation Plan and will be used by the
consultant conducting the water rate study.
5. RECOMMENDATION
R ei a is a ort and provide comment.
d Ta for Michael D. HoHey
Water Utility Manager General Manager