20090130Lost, Unaccounted-for Gas Report.pdf

EXECUTIVE OFFICES
INTERMOUNTAIN GAS COMPANY Dcr:i:lj~t~_Vl,,i'
555 SOUTH COLE ROAD. P.O. BOX 7608. BOISE, IDAHO 83707. [phone]. FAX: [phone]
2U69 JAN 30 PI1 12: 59
January 30, 2009
Ms. Jean Jewell
Idaho Public Utilities Commission
472 W. Washington St.
P.O. Box 83720
Boise,ID 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 Utilities 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 [phone].
Very truly ours,r/t~
Micha¿ McGrath
Director
Gas Supply and Regulatory Affairs
MPM/sc
Enclosures
cc: K. F. Morehouse
E. N. Book
S. W. Madison
An inter-disciplinary team at Intermountain Gas Company was established several years
ago to investigate and take remedial action towards the level of Lost and Unaccounted for
Gas ("LUAF") on Intermountain's distrbution system. Simply stated, LUAF is the
difference, or variance, between the volumes of natural gas purchased to serve the needs
of our customers and the volumes biled to those same customers. To-date, Intermountain
has identified, employed and evaluated several processes that address the recovery of lost
gas - which is to say a reduction to the level of Lost and Unaccounted for Gas. Curently,
Intermountain Gas Company has one of the lowest levels of LUAF in the natural gas
distribution industry.
The below information is a sumary of those processes that have addressed LUAF at
Intermountain. While all the processes are basic by nature, some processes are more
complex to administer than others.
The more straightforward LUAF identification methods include billing and meter audits.
Billng audits utilize variance reports whereby an auditor reviews billed consumption as
compared to some standard. "Low Usage Reports" are used to compare biled
consumption against that same customer's historical usage pattern for a given Heating
Degree Day. Ifbiled consumption appears low in relation to that historical usage pattern,
a technician might be called out to fuher investigate the meter in question. "Zero Usage
Reports" help to identify those meters where usage is arguably taking place but not
registering on the meter (dead meters). Additional audit reports allow the auditor to
review billed consumption for a given "meter size." There should arguably be a
correlation between the customer's billed volumes and the size of the meter installed to
serve that customer. These types of correlated audits sometimes identify malfuctioning
meters and at other times identify a problem with the programming in place that
translates metered consumption to biled consumption. The term "foot drive error," for
instance, is used to characterize a biling error whereby the customer's meter was
functioning properly but Intermountain's billing system was improperly programed to
recognize and account for those consumed volumes. Also in relation to biling audits,
regular comparsons are made between the natural gas delivered onto Intermountain's
distrbution system according to the interstate pipeline vs. those same volumes as
measured by the Company's Gas Control Department.
Meter audits include a multitude of measures. Regular meter sampling occurs whereby
meters are pulled from the field and tested in a laboratory for accuracy. If these types of
sampling audits were to determine that the accuracy of certain "batches" of purchased
meters were in question, additional targeted samples take place and any necessar follow-
on remedial measures are taken. In addition to these regular meter audits, Intemiountain
has undertaken additional steps to identify the potential for incorrectly sized and/or type
of meter in use by our larger industrial customers. Some industral customers consume
natural gas differently over time as may be related to changes in the economy, plant and
equipment improvements, conservation measures, etc. A meter size and/or type (and
corresponding accuracy with respect to consumption) which may have been waranted at
the customers premise a decade ago may no longer be applicable today and a change in
installed meter size and/or type might be warranted. Many of our large industral
customers have "Scada" measurement devices installed at their premise which facilitate a
monthly comparson to the biled volumes as determined by the customer's meter. If a
discrepancy exists between the two measured volumes, remedial action is taken.
Also related to meter audits, and in conjunction with the billng audits previously noted,
Intermountain has undertaken steps to improve biling accuracy of installed meters by
establishing quality control measures that require additional "eyes on" for both newly
established meter sets as well as groupings of meters already established in the field.
Techncians are dispatched to "double check" the biling determinants assigned to these
meters.
Also in relation to meters, Intermountain designed and implemented three (3) "field labs"
on segregated (or isolated) sections of its distrbution system. These labs facilitated
measurements allowing for comparison of the throughput from various main feeds into
Intermountain's distribution system to the combined volumes metered at the end-use
customers.
On a regular and programed basis, Intermountain technicians traverse the entire
distrbution system of the Company with sophisticated equipment that can detect even the
smallest leaks in our distrbution system. When such leaks are identified, which is very
infrequent, remedial action is immediately taken. Unfortunately, human error sometimes
leads to unintentional damage to our distribution system by an outside contractor or even
a homeowner. When such a situation occurs, an estimate is made of the escaped gas and
that gas then becomes "found" and not "lost."
The calculations involved to convert metered cubic feet to bilable therms include inputs
related to pressure, temperature and Btu content. These required billing determinants are
applied in conjunction with industry standard formulas to arve at billable volumes. This
biling method is employed by both Northwest Pipeline (inputting to our distrbution
system) as well as Intermountain Gas Company when billing end-use customers. Great
care is given to allow for accurate determinations of these key biling determinants -
pressure, temperature and Btu content.
In addition to Intermountain's internal efforts to mitigate the overall level of Lost Gas,
other distribution companies have been contacted over time to investigate their efforts
towards the remediation of LUAF. When additional measures used by these companies
seem to have merit, the aforementioned team takes action.
Again, the above was meant to provide an overall sumary of the actions taken to
mitigate LUAF. The Company looks forward to discussions with the IPUC Staff in the
hopes of fuher improving upon our efforts to date.