NorthWestern Energy Bozeman: Progress Reports

NWE Bozeman Update (8/6/2009)

Thu, 06 Aug 2009 12:34:24 GMT

NorthWestern Accelerates Downtown Maintenance

NorthWestern Energy is planning to accelerate its natural gas System Maintenance Program in four communities this summer, including Bozeman, after it decided to defer another gas project elsewhere in the state. Beginning the week of August 10 crews will be working in the downtown area removing inside gas meters and installing new outside meter sets, removing inactive “stub” lines from the main and installing new fittings and valves on the main line. The new valves and fittings will enable the company to respond to local customer requests to create a smaller zone around the downtown area. Stop by the downtown office at 308 E. Main for details, maps and work schedules.

NWE Bozeman Update (4/29/2009)

Wed, 29 Apr 2009 13:00:58 GMT

The Bozeman Division’s annual leak detection survey program started on April 27 and will continue through June 12. The company hired an outside contractor, Heath Consultants, to conduct the surveys, which involves people walking above the gas system and using “sniffer” equipment that can detect the presence of natural gas in the ground. They are also checking meters for possible leaks or malfunctions.

Annual leak detection surveys are conducted in each community’s downtown business districts, the company’s transmission and distribution lines in the area, and include 25% of the residential services. Residential services are required to be checked every five years; however, the company divides each community into quarter sections and tests on the equivalent of every four years. Once the downtown area is surveyed, surveyors will move to the residential area included in this year’s survey and after that will work on the other communities in the Bozeman Division including Livingston, Belgrade, Manhattan and Three Forks.

On April 27, surveyors detected a potential gas leak in the north Main alley behind the Gallatin County Courthouse. The main line was excavated and crews repaired a leak and the hole will be refilled on April 29. Another gas leak was detected on April 28 behind Gallatin Laundry and was excavated. As of this posting, the work had not been completed. Neither of these situations involved leaks of gas sufficient to cause hazardous conditions.

The leak detection surveys are intended to identify small leaks before they pose a safety concern. NorthWestern’s standard protocol is to immediately address any potentially hazardous problems identified by surveyors. The company inspects more than 2,000 miles of pipe and approximately 45,000 services in Montana each year and typically finds and repairs several leaks per division during the annual leak survey.

NWE Bozeman Update (4/8/2009)

Wed, 08 Apr 2009 16:36:38 GMT

The following is a letter that was sent on Monday, April 6 to several community members in response to a letter they had sent to the company. Also on April 6, NorthWestern Energy representatives provided a brief informational session on the incident, status of the investigation and potential next steps to members of the Gallatin Valley legislative delegation in Helena. The letter summarizes the information shared with the legislative delegation.

Investigators have been at the scene this week gathering evidence as part of the ongoing civil investigation.

Copy of April 6, 2009 letter:

Dear -

Thank you for your March 25^th letter requesting information about the natural gas system in Downtown Bozeman. NorthWestern Energy is committed to operating our natural gas system and electric system safely, understands the concern of Bozeman citizens, and wants them to be confident in the safety of our system.

We have a dedicated staff that takes safety seriously and are highly trained in natural gas operations. Northwestern has in place active and systematic operating and maintenance programs for all of its natural gas systems and we update our programs as innovations are made in the industry. Additionally, we comply with the rigorous requirements mandated by the Federal Department of Transportation Pipeline Safety program, as administered at the state level in Montana by the Montana Public Service Commission.

We are continuing to investigate the incident that occurred on March 5th and anticipate it will take between three and six months to gather the necessary facts and analyze the pipe, soil, weather conditions, and customer piping in order to determine what caused the fracture at a coupling in a two-inch service line. As our investigation continues, our management and our engineering staff are also taking a broader view of the situation in order to address any safety concerns that are identified with the Downtown Bozeman pipeline system.

Among the actions NorthWestern has already taken are:

1. Immediately following the incident multiple odorant tests were conducted to determine that our gas, if it were to leak, would be readily detected by smell. These tests confirmed that gas was properly odorized and readily detectable at levels well below dangerous levels.

2. An extensive ground survey and leak survey was also conducted in the area of the incident to identify any possible gas pockets that may have accumulated from any source of gas. These tests were negative, indicating no other leaks.

3. Since the incident occurred there have been many samples of physical pipe removed from this system as part of the investigation. We have found absolutely no evidence of deterioration due to corrosion, which is a potential cause of leaks. It is evident that the cathodic protection NorthWestern maintains to interrupt corrosion is working very well. We are confident that the 8 inch main and the service lines that serve this area are safe and in good condition.

4. The service lines that were part of the system within the immediate area of the explosion were all replaced while the main was restored to service. We had no reason to believe that these services needed replacement; however, it is our normal operating procedure when a system is out of service to accelerate routine replacement schedules as it avoids further interruption of the gas service. All replaced materials, like those described above, were in very good shape, further confirming that the cathodic protection system is working well.

5. As part of normal operating procedures all lines were pressure tested before going back in service to determine whether there were leaks on the system. There were none.

6. We also initiated an open communication process with the business owners in downtown Bozeman, as well local officials.

There has been concern raised about adequacy of NorthWestern’s mapping and facility locations. Our maps accurately showed all available control devices and general locations of all pipelines. However, in responding to the emergency a human error was made reading the maps which resulted in an additional stopper fitting being installed. This stopper fitting did provide additional benefits in that it limited the number of services affected.

I realize that the public is concerned about the length of time it takes to isolate a natural gas system following an incident. We believe that the operating decisions that were made that day were made in the interest of overall public safety.

Shutting down natural gas systems is a complicated operating matter and is much different than shutting down electric or water systems. Our system is zoned (Bozeman has ten zones), is designed to be shut down in the event of a catastrophic operating failure, and all emergency valve locations were known.

We were prepared and able to shut down service to downtown; however, because of the weather conditions and consequences that would have occurred by shutting down service in below-freezing weather, we chose to isolate the system through the use of stopper fittings.[1] This is a normal emergency response to a situation like this, where a release of gas is contained and can be isolated, affecting the smallest number of customers. While using stopper fittings takes additional time, compared to simply shutting off gas, installing all of the stoppers allowed us to isolate the affected portion of the gas main to about one block, which ultimately led to the fewest gas services being interrupted.

Because such events are rare and it is impossible to predict where they may occur, and because of many operating reasons, including safety considerations, it is impractical to install valves every few blocks. That is why it is common industry practice to have available the means to install a type of valve within a reasonable time at any location through the use of stopper fittings. This provides maximum flexibility and the safest way to methodically shut down gas systems.

Based on ongoing safety and inspection programs, we have no reason to believe that the main or services in this area are not safe; however, our engineers are evaluating the following steps as part of their ongoing analysis:

1. Should more control devices be added? If so, how many more control devices should and could be added and where? There are pros and cons to increasing the complexity of a natural gas system. All of the risks and benefits need to be evaluated. Our initial thinking is to add additional redundant stopper fittings in the downtown area. We believe this is the most effective way of adding the most control; avoiding undue interruption of service; limiting maintenance and safety issues; and, minimizing siting challenges associated with above-ground valves.

2. Should additional leak surveys be conducted? Federal Department of Transportation rules do not require additional leak surveys following an incident. We are sensitive to the concerns that have been expressed, however, and in response to those concerns NorthWestern will increase its leak surveys of Downtown Bozeman for the remainder of 2009.

I hope this letter is responsive to the questions you raised, and that the information provides a better understanding of what NorthWestern has done and continues to do. Again we take this situation and the safety concerns of the Bozeman residents seriously. I look forward to meeting to further discuss this important subject. We are concerned to provide our customers factual information about their energy services.

Sincerely,

Robert C. Rowe

President and CEO

[1] Bozeman’s natural gas system is divided into ten zones. Because of the volume of gas required on the day of the event, it would have been necessary to shut down two zones in order to maintain pressure on the rest of the system.

NWE Bozeman Update (3/31/2009)

Tue, 31 Mar 2009 18:41:25 GMT

Crews have installed the last remaining gas service in the alley to the old Bozeman TV and Appliance building. The crew also removed a portion of the soil that had been in the alley between Rouse and Bozeman and expect to have the remaining soil removed within the next day or two. Inclement weather prevented the slurry mix used to fill the bigger holes from completely setting over the weekend, so the alley remained closed through Monday. On Tuesday, the area will be tested to ensure the ground is stable for traffic before restoring complete access to the alley. The company plans to patch the excavation holes with asphalt later this spring.

NWE Bozeman Update (3/27/2009)

Fri, 27 Mar 2009 13:43:39 GMT

Permanent new underground gas service lines have been installed to all but one of the businesses in the 200/300 blocks of East Main and the temporary above ground service lines have been removed. The new gas service line to Bozeman TV and Appliance will be run on Friday. Gas service has been restored to all but two businesses (Bozeman TV and Appliance and the Rocky Mountain Rug Gallery), which are still awaiting an okay from the City’s Building Inspector before meters can be installed. The entire pipe has been wrapped and on Friday crews will fill in the remaining holes with a non-shrink slurry back fill. The fill material will need to “set” (not unlike concrete) over the weekend before access to the alley can be completely restored.

NWE Bozeman Update (3/26/2009)

Thu, 26 Mar 2009 12:50:31 GMT

On Wednesday, March 25, NorthWestern Energy’s gas transmission crew from Deer Lodge replaced a 40-foot section of main and installed a new valve behind the Bozeman Hotel. The City is providing a manhole and cover to provide easy access to the valve in the future. The stopper fittings that were installed the night of the explosion have been removed. The main and service lines were purged and pressurized with nitrogen for testing then re-pressurized with natural gas.

Permanent gas service to customers on the west end of the explosion site was restored by early evening. The remaining services on the east end of the explosion site will be restored tomorrow once pipe work on the customer side of the meter is finished. Once permanent service is restored, the temporary above ground services will be removed. One building (the Montana Rug Gallery) is awaiting inspection before a new meter can be installed.

All of the electrical infrastructure replacement in the alley is complete; however, individual service will be restored to the Montana Rug Gallery and the old Bozeman TV & Appliance once the buildings are inspected and deemed safe for service restoration

NorthWestern Energy Community Relations professionals have been canvassing the downtown business district talking with business owners since shortly after the explosion took place to gather information and ideas about how the company can participate in the recovery effort. On Tuesday, NorthWestern’s President and CEO Bob Rowe met with many of these Main Street business owners to thank them for their input and suggestions and to let them know that the company is seriously considering many of the recommendations.

NWE Bozeman Update (3/25/2009)

Wed, 25 Mar 2009 12:08:57 GMT

On Tuesday, March 24, Bozeman gas crew completed new service to the Gift Corral and exposed 40 feet of gas main in preparation for the gas transmission crew to install a new section of gas main that will eliminate several retired, service tees. Representatives of NorthWestern Energy have spoken with owners of businesses near the Bozeman Hotel to prepare for replacement of retired gas service with new gas service and it appears the company may have to wait until later in the spring to complete this task to accommodate the needs of both business owners and building owners. A crew from Missoula Division removed the main line dresser fitting, installed a new section of gas main and completed a new service to old Army Navy building. The crew also prepared a section of gas main section for the gas transmission crew to install tie-in section near the stopper fitting west of Bozeman Avenue.

An electric crew from Bozeman Division replaced transformers and equipment needed to serve the Rug Gallery and the old Bozeman TV and Appliance building. The crew also replaced the overhead electric service to the old Bozeman TV and Appliance building. City of Bozeman building inspectors requested that we not turn on electric or gas services to either the Rug Gallery or old Bozeman TV and Appliance building until they have had a chance to inspect each building.

Tomorrow, March 25, a NorthWestern Energy gas transmission crew will arrive about 9:30 am to begin the process of replacing the 40-foot section of main, installing a valve near the stopper fitting behind the Bozeman Hotel, finishing the connection to the main line and preparing the line for re-pressurization. NorthWestern will purge the main and service lines with nitrogen then re-pressurize with them with natural gas. After the main is back in service, NorthWestern crews will reconnect the customers currently served by temporary gas services to the gas main.

NWE Bozeman Update (3/23/2009)

Mon, 23 Mar 2009 12:13:01 GMT

Over the weekend, NorthWestern Energy had a three-man construction crew from Bozeman work about eight hours on Saturday and again on Sunday to replace the natural gas lines to the commercial businesses that are still without service. On Monday, March 23, a three-man crew from Missoula joined a crew from Bozeman to continue replacing the gas service lines as well as to install a coupling on the 8-inch natural gas main. NorthWestern expects that its crews should have all the new 1-inch plastic service lines installed by the end of tomorrow allowing a gas transmission crew to be onsite by Wednesday to tie in the 8-inch main to the service lines and re-establish service by Thursday.

NWE Bozeman Update (3/19/2009)

Thu, 19 Mar 2009 17:28:51 GMT

Crews finished three out of five gas services west of Bozeman Street and placed them into permanent service this evening. Construction on the fourth service line is finished and the fifth service line is expected to be finished by the early next week. Partial access has been restored to the alley behind the Crystal Bar.

Crews will be working over the weekend on the replacement of seven services located east of Bozeman Street. Construction on these services is expected to take several days. Once construction is finished, gas transmission crews from Deer Lodge will remove the stopper fittings in the Main and pressurize the lines.

Investigation at the explosion site continues.

NWE Bozeman Update (3/18/2009)

Wed, 18 Mar 2009 17:29:53 GMT

All of the old services have been retired meaning cut off from the main. Crews started installing the new services on the western end of the project behind the Crystal Bar.

Crews are assisting with the ongoing civil investigation at the site. A joint investigation including representatives of the property owners, insurance companies, and NorthWestern Energy are gathering evidence from the scene to determine the cause of the explosion.

NorthWestern Energy is reaching out to downtown business owners along Main Street to hear and address concerns and to provide information on the work going on in the alley.

NWE Bozeman Update (3/17/2009)

Tue, 17 Mar 2009 16:13:00 GMT

NorthWestern Energy will be replacing all of the gas services that are currently out of service with new plastic pipe on 3/17/09. The work is part of the company’s system integrity plan, which in addition to establishing a regular replacement schedule for certain types of piping systems calls for the replacement to be done out-of-cycle anytime the opportunity to do so presents itself. The work is being done in the alley and will take approximately a week to complete. While this is an inconvenience to the affected businesses, doing the work now eliminates the need for another disruption at a later date. Business/property owners with any questions or concerns about this work should call Mel Kotur, Community Relations Manager, at 582-4637.

NorthWestern Energy has brought in an additional crew from Missoula to help at the work site. In addition to providing relief for tired Bozeman-based gas crews, the company is responding to a higher than normal number of gas odor calls. Anyone who believes they smell natural gas should leave the area immediately and call 911 or NorthWestern Energy at (888) 467-2427 from a safe location.