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California Public Utilities Commission

Guidelines for Preparing

Operation and Maintenance Plan, Emergency Plan,

and Operator Qualification Program for Mobilehome Park Gas Systems

July 2009

Utilities Safety and Reliability Branch

505 Van Ness Ave Rm. 2-D

San Francisco, CA 94102


The purpose of these guidelines is to help operators of natural gas distribution systems within mobilehome parks (Operator) establish a written plan that is in compliance with the requirements of Title 49, Code of Federal Regulation (49 CFR), Section 192.603: Operation and Maintenance Plan, Section 192.615: Emergency Plan, and Section 192.805: Qualification program of the Pipeline Safety Regulations. The numbers appearing in the parenthesis throughout these guidelines represent the applicable code number in the Pipeline Safety Regulations, Public Utilities Code or General Order 112-E. For example, the numbers [49 CFR §192.605(a)] refer to the Pipeline Safety Regulations - Title 49 of the Code of Federal Regulations (CFR), Section 192.605(a).

The information contained in this booklet was prepared by the staff of the Utilities Safety and Reliability Branch (USRB) of the California Public Utilities Commission as an aid to operators of small natural gas systems to prepare written Operations and Maintenance Plan, Emergency Plan, and Operator Qualification Program.

This is not necessarily a complete or definitive outline. Additional information may be required by federal or state regulations. Please refer to Title 49 CFR Parts 190, 191, 192, 193, and 199, Public Utilities Code, and California Public Utilities Commission General Order 112-E for the complete regulations.

This document will be updated as necessary.

Revised in July of 2009


Your Operation and Maintenance Plan should have instructions for employees performing normal operations and making repairs. Include instructions and record keeping procedures in your Operation and Maintenance Manual for topics A-K described below.

A. Normal Operations and Repairs

Identify employee(s) who have a working knowledge of the system and identify person(s) responsible for maintaining the system and correcting any unsafe condition. [49 CFR §192.605(a)].

B. Line Markers

NOTE: This section is not applicable to gas systems in most parks. It only applies to systems that have above ground distribution mains. Distribution mains are pipelines that are a common source of gas supply for an individual customer, or two adjacent or adjoining residential customers. Line markers are not necessary for above ground services.

A line marker is a warning sign for the public. It must be placed and maintained along each section of a main that is located above ground and accessible to the public. The line marker must contain the word "Warning", "Caution", or "Danger" followed by the words "Gas pipeline". Additional specifications for a line marker are listed in 49 CFR §192.707.

C. Patrolling

Patrolling is a routine inspection of the distribution system. It can be done by walking along the pipeline and observing factors affecting safety of operation (e.g. missing or ineffective meter supports, excessive load on any pipeline component, use of the gas piping for electrical grounding, obstructions in regulator vent, etc.). The gas distribution mains in places or structures where anticipated physical movement or external loading could cause failure or leakage must be patrolled at least two times each calendar year, but at intervals not exceeding 7-1/2 months. Records of patrolling must be maintained [49 CFR §192.721].

D. Leak Surveys

A gas leak survey of the distribution system must be made by a qualified individual with a leak detector equipment as frequently as necessary, but at intervals not exceeding 5 years, not to exceed 63 months [49 CFR §192.723(b)(2)]. The leak survey equipment used must be able to detect possible underground leaks.

NOTE: If leak surveys are performed in lieu of an electrical survey for steel systems without cathodic protection, the interval for gas leak surveys must not exceed 3 years [49 CFR §192.465(e)].

Annual leak surveys are recommended when any of the following conditions exist:

The operator must maintain gas leak survey records, related to 49 CFR §192.465(e), for the life of the system.

E. Leak Repairs

Provisions must be made for repair of hazardous or potentially hazardous leaks. The operator must maintain all such repair records [49 CFR §192.703]. Leak repair records should include the following information:

F. Abandonment or Discontinued Service Facilities

Abandonment of a pipeline requires it to be cut at the main (1 foot stub), purged if necessary, and capped at both ends. This renders the line non-jurisdictional.

Whenever service to a customer is discontinued, one of the following must be done [49 CFR §192.727(d)]:

G. Prevention of Accidental Ignition

Provisions must be made to prevent the accidental ignition of gas when a potentially hazardous amount of gas may be released, such as when maintenance is being performed or repairs are made [49 CFR §192.751]. The following provisions should be included:

H. Key Valve Maintenance

A key valve is a valve that can isolate a section of the system or shut down service to the entire system in an emergency situation. The operator must determine the key valve(s) and identify it/them on the system map. Key valve(s) must be checked and maintained to keep it/them operable at least once each calendar year, but at intervals not exceeding 15 months. Key valve maintenance records must be maintained [49 CFR §192.747].

I. Measuring the Odorization of Gas

The operator must conduct a periodic sampling of the gas to assure the proper concentration of odorant. This may be done by a performing a "sniff test" at a location where gas can be safely accessed (e.g. during a meter change-out, at a stove top, etc.) without the danger of gas accumulation or ignition. The test should preferably be performed at a location farthest from the master meter. The frequency of the sampling is to be determined by the operator (Note: USRB highly suggests this activity be performed at least every six months). Records must be kept and maintained [49 CFR §192.625].

J. Corrosion Control Monitoring

For metallic pipes, the operator must maintain records or maps to show the location of cathodically protected piping and related facilities [49 CFR §192.491(a)].

(Note: Plastic pipe does not require cathodic protection.)

The cathodic protection system must be tested at least once each calendar year, with intervals not exceeding 15 months, to assure an adequate level of protection. For impressed systems, the rectifier must also be inspected six times annually with intervals not exceeding 2-1/2 months [49 CFR §192.465(a)].

If any part of the pipeline system has buried unprotected metallic pipe installed before August 1, 1971, the operator must evaluate the unprotected pipeline at intervals not exceeding 3 years to determine the necessity of installing cathodic protection. For distribution systems, especially those with pipelines in a common trench with other facilities, electrical surveys are often impractical and can be cost prohibitive. In such cases, operators can use corrosion, leak repair, and/or gas leak survey records to perform the 3-year evaluation of their system [49 CFR §192.465(e)].

Corrosion control monitoring also entails performing the following two items:

The operator must keep records of each test, survey, or inspection, in sufficient detail to demonstrate adequacy of protection [49 CFR §192.491].

K. Inspection of Regulating Stations

Generally, master-metered gas systems with distribution mains that carry gas to customers at pressure close to that provided by the local gas utility through the master-meter (i.e. ¼ psig systems), are not considered as having regulating stations. Gas systems with distribution mains serving customers through individual service lines terminating at individual service regulators are also not considered as having regulating stations


If a master meter system has one or more regulating station(s) downstream of the master-meter, the operations and maintenance plan must include provisions for their inspection and testing. The regulators and relief devices must be inspected once a year not to exceed 15 months [49 CFR §192.739 and §192.743].

The pressure regulating station must be inspected to determine that they are:

· In good mechanical condition;

· Adequate in capacity and reliability of operation;

· Set to function at the correct pressure;

· Properly installed and protected from vehicular traffic, dirt, liquids, icing, and other conditions that might prevent proper operation

The operations and maintenance must include procedures for the inspection of relief devices. The operator must ensure that the relief devices have sufficient capacity to protect the facilities to which they are connected. This can be done by testing the relief device(s) in place or by review and calculations [49 CFR §192.743].

Every year, the operator must verify that there had been no changes to upstream regulators, such as different pressure, orifice, or type of regulator. If there had been no changes, the operator only needs to review and initial the capacity calculation. If a change is made, the new relief valve capacity calculations must be made and kept on file.


Anyone performing inspections related to 49 CFR §192.739 and §192.743 must be operator qualified; therefore, the operator should seek technical assistance from qualified individuals (e.g. contractors) in order to comply with this requirement, especially if regulator disassembly or station redesign is necessary. Any documentation provided by manufactures related to each type of regulator used on the system must be retained as long the equipment is in use.


A record of this annual inspection must be kept. A sample form is provided below.


Name of Mobilehome Park:

Location of Regulating Station:

Regulator Information

Make: Type:

Size: Orifice Size:

Pressure Rating: Inlet: Outlet:

M.A.O.P. of System to which it is connected:

Operating Pressure: Inlet: Outlet:

Lock Up Pressure:

Monitoring Regulator or Relief Setting:

Was the Regulator Stroked (to fully open)? Yes No

General Condition of the Station

Atmospheric Corrosion: Yes No

Support Piping Rigid: Yes No

Station Guards: Yes No

Area Clean of Weeds and Grass: Yes No

Capacity at Inlet and Outlet pressure:

Corrections Made:



Signature: Date:

    Record Keeping Requirements

    Below is a list of items for which records must be maintained:

    Maintenance Item: Maximum Maintenance Interval:


Leak survey

    Once every 5 years 1



    Two times a year


Key valve maintenance

    Once a year


Odorant check



Cathodic protection (CP) system

evaluation (pipe to soil potential)

    Once a year


CP rectifier voltage and amperage

readings (for impressed systems only)

    Six times a year


Leak repair reports (for underground


    As necessary


Examination of exposed buried pipe

    As necessary


Atmospheric corrosion

    Once every three years


Regulating station inspection and testing

    Once a year


O&M plan review

    Once a year

    1 Note: For non-cathodically protected steel pipelines the interval is once every 3 years if a leak survey is used in lieu of an electrical

    survey. If, however, one of the following conditions exist the recommended interval is once every year:





    The system is constructed of materials which have a tendency to leak, such as unprotected bare steel, PVC, and cast iron.

    The pipeline is over twenty years old and a corrosive soil environment exists.

    There is an excessive leak history, and the causes of which have not been addressed.

    Portions of the pipeline are located under mobilehomes.

    2 The operator must determine the interval at which odorant checks will be performed. This interval should be stated in the O&M plan.

    (Note: USRB highly suggests it is prudent to perform this activity at least every six months).

Sample Maintenance Schedule

NOTE: Clear cells indicate month maintenance is due. Write the date and personnel's initials on the appropriate cells when maintenance is performed.














Leak Survey




Key Valve Maintenance


Odorant Check


Cathodic Protection (CP) Evaluation


CP - Rectifier Readings


Atmospheric Corrosion


Regulating Station inspection and testing


O&M and Emergency Plan Review


The operator's written emergency plan must contain, at a minimum, the following items [49 CFR §192.615]:

A. Emergency Notification List

The telephone number of the pipeline operator, fire department, local serving gas utility (i.e., SoCalGas, PG&E, etc.), and anyone else whose service may be necessary in an emergency must be posted in a public area within the mobilehome park [Public Utilities Code 4361(a)]. A sample Emergency Notification List is included with these guidelines.

For better coordination of emergency procedures, it is recommended that you instruct all residents to notify the office immediately in the event of an emergency (earthquake, fire, or gas leak), even if they have called an emergency service.

B. Map of the Gas Distribution System

A map of the gas pipeline, including the location of the master meter(s), gas main(s), service line(s), and key valve(s) must be included in the Emergency Plan [Public Utilities Code 4354.5(a)(1)]. Cathodic protection facilities may also be indicated on the map.

C. Emergency Equipment

Proper equipment, in particular wrench(s) or valve key(s) of sufficient size to operate key valve(s), must be readily available in the event of an emergency. The equipment and its location must be specified [49 CFR §192.615(a)(4)].

D. Emergency Response Procedures

At a minimum, written procedures for prompt and effective response to the following emergencies must be provided [49 CFR §192.615(a)(3)]:

It is suggested that the operator have an evacuation plan that addresses the following items:

4. A method of verifying that all residents have secured and evacuated their homes is provided.


E. Telephonic Incident Reporting Procedures

Should a reportable incident occur, an operator must call and report the incident, at the earliest practical moment, to the U.S. Department of Transportation (800) 424-8802, and the California Public Utilities Commission (800) 235-1076. A reportable incident is an event involving release of gas from a pipeline and any of the following:

Any event that is significant in the judgment of the operator, even though it may not meet the aforementioned criteria, may be reported [49 CFR §191.3 & §191.5].

F. Restoration of Gas Service

Should gas service to resident(s) need to be restored due to an outage, qualified person(s) must follow the proper procedures to restore the service. A relighting procedure and qualified person(s) must be specified [49 CFR §192.615(a)(9)]. It is suggested that the operator check with the local utility to determine what services they assist with and their associated costs.

G. Training

Appropriate personnel must be trained to assure that they know the emergency procedures outlined in the emergency plan [49 CFR §192.615(b)(2)]. Maintain training records.

H. Public Awareness

Each operator of a master-meter gas system must develop and implement a written procedure to provide its customers, and persons controlling any property, on which the system is located, which is not controlled by the operator, with a Public Awareness Message (PAM) twice annually (every six months). The operator shall maintain records indicating how, when, and to whom the PAM was distributed. The public awareness message must include [49 CFR §192.616(j)]:

An example of PAM is provided below. Please note that the example below is merely a guideline. It is the pipeline operator's responsibility to ensure that all requirements are properly addressed in the PAM.

1. A description of the purpose and reliability of the pipeline




Describe the purpose of the gas pipeline system.

    The natural gas pipeline system in the "Name of Mobilehome Park" is owned, operated and/or maintained by the "Name of the operator of the gas system." The pipeline system is designed to distribute gas to the residents, which is commonly used for heating and cooking.

Note: If there are public facilities such as a pool or laundry room in the mobilehome park, the PAM should also identify these and other facilities that utilize the gas pipeline system.

Describe the reliability of the gas pipeline.

The gas pipeline system is operated and maintained by qualified individuals in accordance with the Operator's Operations and Maintenance Plan, which contains procedures for safely operating, maintaining, and monitoring the system. The California Public Utilities Commission inspects the gas pipeline system for compliance with the Federal rules and regulations.


2. An overview of the hazards of the pipeline and prevention measures used



Describe the hazards associated with the pipeline.

Gas can leak from pipeline facilities damaged due to corrosion, outside force, environmental factors, natural events, or equipment failure, etc. Because natural gas is a flammable commodity, gas leaks, under certain circumstances, can be dangerous.

Describe preventive measures used.

    The gas system is leak surveyed by qualified individuals on a frequency of "operator's frequency" years. By law, under no circumstance can we exceed a period of 5 years without performing a leak survey. We are required to immediately repair all hazardous leaks, and schedule for repair, or monitor, all leaks which are non-hazardous. Leaks in confined spaces, and leaks immediately near sources of ignition are generally classified as hazardous leaks. All valves necessary to isolate the system, or parts of the system, are inspected annually to ensure that they are operable. The gas system is patrolled on a routine basis to ensure that hazardous conditions such as atmospheric corrosion, improper care of discontinued services and customer lines, inadequate support of meters and pipeline components, etc., are noted and corrected.

Note: If the gas pipeline system is cathodically protected, briefly explain that the gas system has a cathodic protection system that protects the pipeline from corroding and that this system is monitored at least annually to ensure its effectiveness. Residents should be instructed to keep all metal objects that can short the cathodic protection system (i.e., chains, grounding connections, etc.) away from the meter-sets.

3. Information about damage prevention



Describe how the pipeline can be damaged.

The gas pipeline system is susceptible to damage due to outside forces such as those caused by excavation, vehicular traffic, or excessive loads placed on meter set assemblies. In addition, anything that obstructs access to main valves and service valves on meter set assemblies could result in severe consequences in the event of an emergency.

4. How to recognize and respond to a leak



List ways to recognize gas leaks.

    Odor: Natural gas is colorless, odorless, tasteless and non-toxic. An additive (Mercaptan) is added by the gas company to give the gas a distinctive odor (similar to rotting eggs or sulfur) so any leaking gas can be readily detected.

    Vegetation: Natural gas leaking from an underground pipeline can destroy vegetation by starving the roots of air and water. An unusual dry patch of vegetation, within an otherwise green area, could indicate a below ground gas leak.

    Sound: A blowing or hissing sound could indicate the presence of a gas leak.

    Bubbling Water: Gas leaks on underground pipelines in flooded areas may cause bubbles in the water as the gas rises to the surface.

    Fungus-like growth: Gas leaks in valve boxes, manholes, etc., may develop a fungus-like growth that is generally white in color.

Describe how to respond to a gas leak.

Do not light items such as matches, cigarettes, or any other device that may generate a spark and ignite gas in a gaseous environment. Devices such as electrical switches, telephones (cell and land line phones), doorbells, automobiles, other engines, static electricity, etc. can all generate a spark capable of ignition. Extinguish all flames, evacuate occupants of the structure, and possible neighboring structures, to a safe distance, and turn off the gas at the service valve, if feasible. Venting of the gas should consider gas concentration and the need to terminate electric, telephone, and other sources of ignition from their respective service connection points outside the structure. To report a gas leak, call (Emergency Phone Number) and inform Operator personnel of the situation and the location of the leak. Do not make the phone call from the area where the gas leak is present.

For gas emergencies, an emergency telephone number should be provided where operator personnel can be reached 24 hours a day.

5. How to get additional information



Provide the phone number for the operator, and other potential resources, where customers can learn more about gas safety.

    For additional information, contact the Operator of the gas system at "phone number." Also, visit the websites of the U. S. Department of Transportation, Pipeline and Hazardous Materials Safety Administration ( http://www.phmsa.dot.gov) or the California Public Utilities Commission ( http://www.cpuc.ca.gov/puc/).

I. Accident Investigation

Each operator needs procedures for an investigation of all accidents and failures for the purpose of determining the cause of the failure and minimizing the possibility of reoccurrence [49 CFR §192.617].

Name of Mobilehome Park: _________________________________________________

Manager Telephone
Asst. Manager Telephone

Emergency Numbers

Fire Department

Police/Sheriff Department


Gas Company

Electric Company

Phone Company

Incident Reporting:

California Public Utilities Commission (800) 235-1076

U.S. Department of Transportation (800) 424-8802

Nearest fire alarm box ______________________________________________________

Nearest Public Telephone ___________________________________________________

Nearest Hospital:

(FORM MHP-3) REV. 9/00)






Pursuant to General Order No. 112-E, any jurisdictional operator of a master-metered natural gas distribution system is required to give notice of certain incidents to the federal government as well as to the California Public Utilities Commission (CPUC).

At the earliest practicable moment, day or night, following discovery of any of the incidents listed below, a telephone report of the incident must be made to the CPUC by calling 1-800-235-1076, and to the U.S. Department of Transportation at 1-800-424-8802. If, when calling the CPUC, there is no response, leave a message on the recorder.

Incidents requiring a telephone report.

Information that must be provided when reporting an incident.

1. Names of operator and person making the report along with telephone numbers.

2. The location of the incident.

3. The time of the incident.

4. The number of fatalities and personal injuries, if any.

5. A description of the incident including all significant facts that are known by the operator that are relevant to the cause of the incident and extent of the damages.

NOTE: Failure to provide a notice of an incident, in accordance with General Order No. 112-E, may subject the owner /operator to regulatory action and for penalties.

Title 49 CFR Part 192 Subpart N- Qualification of Pipeline Personnel became effective on October 26, 1999. It requires pipeline operators to develop and maintain a written qualification program for individuals performing covered tasks on pipeline facilities. The intent of this qualification rule is to ensure a qualified work force and to reduce the probability and consequence of incidents caused by human error.

What it requires

The regulations require that you prepare and follow a written OQ program that at a minimum includes the following eight provisions:

What types of records are required

How to get more information

A guideline for preparing an Operator Qualification Program for smaller distribution systems is available on the Department of Transportation website: http://www.phmsa.dot.gov/pipeline/tq

The Utilities Safety and Reliability Branch will continue to include Operator Qualification requirements in its workshops held in conjunction with the U.S. Department of Transportation. If you have questions, you may contact the Utilities Safety and Reliability Branch by mail at:

California Public Utilities Commission

505 Van Ness Avenue, Room 2-D

San Francisco, CA 94102

Attention: Mobilehome Park - Gas Safety Program

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