HomeMy WebLinkAbout20090501Lost, Unaccounted-for Gas Report.pdfEXECUTIVE OFFICES jJr .'*INTERMOUNTAIN GAS COMPANY
555 SOUTH COLE ROAD. P.O. BOX 7608. BOISE, IDAHO 83707. (208) 377-6000. FAX: 377-6097 2009 HAY -I AM 11: 29
April 30, 2009
Ms. Jean Jewell
Idaho Public Utilities Commission
472 W. Washington St.
P.O. Box 83720
Boise, 10 83720-0074
RE: Intermountain Gas Company's Quarterly Report pertaining to Lost and
Unaccounted for Gas
Case No. INT-G-08-03
Dear Ms. Jewell:
Attached for filing with the Idaho Public Utilties Commission are the original and seven
copies of Intermountain Gas Company's Quarterly Report pertaining to Lost and
Unaccounted for Gas.
If there are any questions regarding the attached, please contact me at (208) 377-6168.
Michael ZfJ
Director
Gas Supply and Regulatory Affairs
-
MPM/sc
Enclosures
cc: K. F. Morehouse
E. N. Book
S. W. Madison
REC::!'l
ZOû9HAY -I Ai1l1: 29
INTERMOUNTAIN GAS COMPANY
Responses to IPUC LUAF Gas Questions
Question No.1: Address LUAF. Does this team stil meet? Ifnot, why not? Ifso, who is on the team
and what is it currently working on? What processes has it "identifed, employed and evaluated that
address the recovery of lost gas"? What informational source or statistics does the Company use to
conclude that it has one of the lowest levels of L UAF in the natural gas distribution industry?
Response: There is a working team at Intermountain comprised of a lead person from the deparments
of Billing Audit, Engineering, Accounting, Gas Supply, Gas Control, Meters and Information
Technology. The processes identified and evaluated that address the recovery of lost gas are included
herein as well as earlier reports sent to the Commission. A project curently underway that emerged
consequent to the joint efforts of this team involves an audit of the Company's commercial ALlOOO
meter sets. Given the magnitude of the billing error than can occur on these larger meters due to the
annual throughput on a typical ALIOO meter, and, given the manageable size of this meter population,
all 5,000 of these meters are being included as par of a current audit process. An update of the findings
of this audit will be included in the next Lost Gas report to the Commission. In conjunction with
queries made to other local utilities as well as statistics provided by Southern Connecticut Gas based
on a 2004 DOT Report, Intermountain believes it has one of the lowest LUAF levels in the natural gas
distribution industry.
Question No.2: You state that the Company conducts biling audits utilzing "variance reports
whereby an auditor reviews biled consumption as compared to some standard. " What is the standard?
How many of these audits were conducted in 2007 and 2008? Please provide examples of these audits
and how the "Low Usage Reports" have trended over time. Please provide any information developed
by the Company showing how variance reports have trended over time.
Response: The "standard" depends upon the tye of audit being conducted as more fully outlined on
the Company's report dated Januar 30, 2009. There are two main usage audits performed with each
biling cycle - Low Usage and Zero Usage. The desired outcome of these audits is to discover any
inaccurate billings due to the malfuctioning of the customer's meter. Although close to 200,000
billing audits are performed by the computer annually, only a very small percentage of these audits
warrant further attention as outlined as par of the response to Question NO.3 below.
The "low usage" report analyzes each meter read in every cycle. It calculates the curent measured
usage and compares this usage/consumption to the previous year, same period for each premise. If the
disparity is greater than 60% variance, the account appears on the report with the curent usage (in
CCF), the previous year - same period usage along with the usage from the previous month as a frame
of reference. The analyst then reviews the account usage history to determine if the disparty is not in
line with historical usage. Based on their personal judgment, the account is flagged for either a
couresy phone call to determine if there is valid reason for the lower-than-normal usage, or a check-
Intermountain Gas Company
Response to IPUC LUAF Questions
Page 2
for-dead order is generated for the following day and a service technician is dispatched to field test the
meter for fuctionality.
The standard used for 'zero usage' accounts is, again, the customer's consumption history and any
relevant notes made on the account by the Customer Service Center. An account that is documented as
"off' by the system, does not appear on this report. Only those accounts that there would be some
expected consumption appear on this report. Again, personal judgment based on historical usage and
any relevant information that can be gleaned from any notes is utilized. Based on the outcome of this
analysis, a 'check for dead' order may be generated.
As previously stated in the LUAF report, the standard utilized is the customer's own historical
consumption at that premise, or in the event the customer has not occupied the premise for a period of
time that would allude to 'typical' usage, the historical usage on the premise is used as the determinant.
Question No.3: Please provide any information developed by the Company that shows how
"correlated audits" that look at the "correlation between the customers' biled volumes and the size of
the meter installed to serve that customer" have trended over time in terms of malfunctioning meters
and programming problems ("foot drive error"). How many biling audits were completed in 2007 and
2008? How often has this type of audit determined that customers may have too large or small of
meters?
Response: Since 2007, Intermountain had provided the IPUC with Excel formatted Meter Adjustment
Reports that contain the data necessary to evaluate trends in malfuctioning meters.
In 2007 Intermountain performed 7,382 "check for dead" billng audits; 520 or 7% of these meters
were determined to have been dead. 2008 audits yielded 5,088 "check for dead orders" and 708, or
13 %, were found to be dead.
Drive rate errors have decreased 39% (from 43 to 26 in 2007 and 2008 respectively). Pressure errors
are down approximately 9% between these two years while the total dollar adjustments for errors of
this type have decreased a total of 56%.
Question No.4: In relation to biling audits, how often are the "regular comparisons made between
the natural gas delivered onto Intermountain's distribution system according to the interstate pipeline
vs. those same volumes as measured by the Company's Gas Control Department?" Please provide any
information developed by the Company showing how these regular comparisons have trended over
time.
Response: Intermountain compares its telemetered usage vs. the metered usage that Northwest
Pipeline (N) records on a daily and monthly basis. These frequent comparsons enable
Intermountain to find any material measurement variances with NW's figures.
Intermountain's Gas Control deparment keeps historical telemetr records and variance-to-pipeline
calculations. These records indicate the tyical monthly varance for all compared te1emetered gates is
Intermountain Gas Company
Response to IPUC LUAF Questions
Page 3
0.5 % making trending unecessar. If a measurement error were to occur, such an error will typically
throw the daily comparisons off by approximately 5% or more, thus raising a red flag which wil lead
to further investigation.
Question No.5: How often does Intermountain Gas conduct "regular meter sampling whereby meters
are pulled from the field and tested in a laboratory for accuracy"? What "multitude of measures" do
meter audits include? How does Intermountain Gas sample? Please provide any information
developed by the Company showing how identifed meter accuracy resulting from this sampling has
trended over time.
Response: Intermountain Gas Company conducts continuing samplins of our residential ~ter
population throughout the year, with a sample year beginning on June 1 t and ending May 30t of
following year. A rotation plan is developed by applying the MILI05D standard for sampling to the
eligible families of company meters in service. These meters are then pulled from the field in the lot
quantities assigned to respective years and brought to the meter shop for testing. The results of this
testing is evaluated by meter family to determine the pass/fail of a family based on sampling procedure
allowable defects.
During testing, meters are checked for registration accuracy and consistency of measurement between
the mechanical meter index and the ER T unt.
No trends that affect the Company's testing program have been discovered through the use of data
records from meter testing program.
Question No.6: How often does Intermountain Gas conduct audits to determine which industrial
customers may be consuming gas diferently than they were a decade ago and therefore have meters
that may have been warranted in the past and are no longer applicable today? Please provide any
information developed by the Company summarizing the results of meter adequacy audits and how
audit results have trended over time.
Response: Monitoring of industral customer loads is ongoing and equipment relevancy is evaluated
anually. If an industral customer requests a change in their deliverable volumes, this request would
also warant an evaluation of the customer's existing meter size/set. In addition, on-site changes to
customer facilities initiate a review of curent metering packages to determine if changes in equipment
are waranted. Any material differences in the customer's therm consumption are investigated as they
become apparent. Any necessar meter equipment changes are handled by each applicable district in
conjunction with its Meter Department.
Durng the bi-annual Integrated Resource Plan process, Industral customers are asked to fill out a
surey which provides information relating to plans for facility changes and estimates of natural gas
usage for the next five-year period. This forecast data is then compared to monthly, annual and longer-
term trends in actual therm use which may then warant potential changes to a customer's meter set.
Intermountain Gas Company
Response to IPUC LUAF Questions
Page 4
Question No.7: How many and what percentage of commercial and industrial customers have
"Scada?" Are there plans to install more?
Response: Intermountain has installed SCADA on 89 of our 11 0 Industral customers (81 %). These
89 tele-metered Industrals typically account for the vast majority of industrial usage. For example, the
tele-metered customers used 97% (2,233,375 Dth) ofthe total 2,304,983 Dth biled in Januar 2009.
Intermountain continues to work towards installng SCADA at the facilities of its un-tele-metered
customers. Two additional Industrial accounts should be converted to SCADA in 2009 and per
paragraph 6.2 of Section D of Intermountain's General Service Provisions, all new contract (i.e. Large
Volume) accounts are required to have telemetry installed prior to initiation of Large Volume service.
Question No.8: Please specif what steps have been taken by Intermountain to improve billng
accuracy and quality control of installed meters. Please provide the technician dispatch schedule and
a description of other field review methodology use to provide additional "eyes on" or "double
checking" to assure biling determinates are properly assigned to meters.
Response: A process is now in place to create auto-dispatch orders to audit any meter that has other
than a one-foot drve that delivers ounces of pressure to the customer. These are generated and worked
within the first two weeks of any new meter set or change in equipment and/or pressure at a customer
location in order to rectify and correct billing parameters from the initial meter data entr.
This Meter Audit process is for all meters larger than 400 CFH and meters smaller than 400 CFH if
they have pounds delivery or a 2 foot drve. The process calls for a different Service Tech than the one
who installed the meter to perform an audit of the delivery pressure and drve rate as it relates to the
customer and meter manufacturer requirements. If there is a correction, the timing allows
Intermountain to make any correction prior to the first bil going out. The audit order is created 10
days after a meter is set and must be completed by 30 days after the initial meter set.
Question No.9: On what basis did the Company select the location of "field labs "? Please provide
the results for 2007 and 2008 of the field lab comparisons of main feed throughput and metered end
use consumption.
Response: The field labs were identified based on system constraints and the goal of the testing. The
goal of one test was to compare Wiliams meter measurement with IGC tubine/rotar measurement
with a population of domestic meters. For this we needed to identify a community that was only being
fed by one Wiliams/IGC tap. Four towns were identified and based on customer count and time to
read meters. Inom, Id was selected for this test.
The second test was intended to compare a rotar and tubine meter in low flow conditions to validate
turbine meter manufacturer's data suggesting that turbine meters begin to lose measurement when
operating at 15% or less of meter capacity. We were able to isolate a subdivision adjacent to the
company and set up the meter ru on our property.
Intermountain Gas Company
Response to IPUC LUAF Questions
Page 5
We leared through the first test that our domestic meters compared to Intermountain's larger meters
compared to Wiliams' measurement was accurate.
We validated through the second test that tubine meters do in fact lose measurement when operating
near the 15% capacity and lower.
Question No. 10: Please provide the "regular and programmed basis" schedule that Intermountain
technicians follow to detect leaks in the entire distribution system. Please provide monthly leak
detection results for the years 2007 and 2008.
Response: IGC conducts leak surey of our distrbution system per PHMSA code section 192.723,
which requires the operator to conduct leak surey in business distrcts anually not to exceed 15
months, and outside business distrcts every 5 years not to exceed 63 months. Additionally, anytime
we receive an odor call from a customer, we respond as an emergency. The results of these tests are
being collected and wil be reported under separate cover.
Question No. 11: How is the estimate made of the escaped gas when human error leads to
unintentional damage to the distribution system by an outside contractor or homeowner? Please
provide the number of situations occurring in 2007 and 2008 and the amount of 'found" gas estimated
as a result of these situations.
Response:
Gas loss, as it is commonly referred to, is calculated based on the line pressure, the size of hole in the
line, size of the line and amount of time natual gas escaped. A sumar of findings for 2007 and 2008
is shown below:
2007 - 656 occurences
2008 - 495 occurences
254,455 therms of gas loss calculated.
182,920 therms of gas loss calculated.
Question No. 12: What is the calculation for converting metered cubic feet to bilable therms and has
Intermountain Gas found errors in its conversion due to pressure, temperature, and BTU readings?
What are some examples that ilustrate the "great care" Intermountain Gas takes in accurately
determining these biling determinants? How has human error been a cause of calculating or
determining the accurate billng determinants? What was the impact in 2007 and 2008 of conversion
calculation error on lost gas totals?
Natural gas meters measures the flows of gas that moves though its plenum in terms of a volumetric
measurement recorded in cubic feet. The calculation for converting cubic feet to an energy or thermal
value (i.e.Therm) (as previously demonstrated to the Staff by Staff member David Schune), is based
on a simple multiplication of three parameters: the average temperature, the Btu factor, and
atmospheric pressure. There were no errors found in the billing of these three parameters. There was,
however, refinements made to the each of the parameters as discussed below.
Intermountain Gas Company
Response to IPUC LUAF Questions
Page 6
Daily temperatures are derived from NOAA's certified weather sites or sites defined by
DTN/Weatherlogics when NOAA data is not available. Whenever there is a missed observed
temperatue, DTN provides data from an alternative weather site that is within a close weather
proximity to the station with missed data. Temperature information is interfaced into our biling
system through an automated process.
Btu factors are provided by Northwest Pipeline and are internally reviewed by our Gas Control
departent. Btu factors are also interfaced into the Biling System through an automated process. Both
Temperature and Btu factor integration processes are reviewed by our internal data control group
before they are approved to be used for biling.
Because Intermountain's service terrtory is widespread with diverse meteorological conditions, the
Company increased the number of locations where daily temperature data is used to better match the
weather experienced by our customers across a wide geographic service terrtory.
We also matched the altitude of our cities to the altitude provided by the US Geological Surey
organization for that city. Every altitude has a corresponding atmospheric pressure. Prior to automated
interfaces, manual entry was used. Automating with human verification reduced the potential for error.
The above refinements to the billing metrcs, the Company believes, contrbute towards a more
accurate billing system and therefore a mitigation of any lost gas which may have been present absent
these refinements.
Question No. 13: What additional measures used by other companies in their efforts toward
remediating LUAF has Intermountain Gas found to have merit and therefore adopted? Which
measures has Intermountain Gas investigated and found not to have merit. What other companies has
intermountain contact regarding LUAF?
Response: Although Intermountain chose on its own accord to more closely evaluate and, when
necessar, enhance the biling determinants used in its biling process (see Q12 above), the Company
also subsequently determined that other companes had also performed similar audits to their billng
metrics to increase the billing accuracy of their own billing systems. Intermountain has also found that
the types of regular meter/billing audits in-use by the Company are also being used by other companies
as well. By way of contrast, "older" companes have in place older infrastructure (cast iron and in some
cases even wood piping) requiring much more aggressive infrastructure upgrades to help mitigate any
lost gas. The problem of theft is also more prevalent in more populated areas of the mid-west and east
and some companes have chosen to dedicate full-time attention to remediate gas theft on their
distribution systems. In addition to phone calls made to local distrbution companies, Intermountain
held a meeting with Michigan Consolidated Gas Company to discuss their lost gas efforts and also
acquired lost gas studies performed by both Southern Connecticut Gas and Southwest Gas. As well, the
aforementioned team members endeavor to share their efforts to remediate lost gas with others as they
attend industry related events.