# NORTHERN NATURAL GAS CO — Warning Letter

- **operation:** document
- **citation:** CPF 32021002WL
- **title:** NORTHERN NATURAL GAS CO — Warning Letter
- **source type:** enforcement
- **agency:** Pipeline and Hazardous Materials Safety Administration
- **status:** historical
- **official:** true
- **published on:** 2021-01-15
- **effective on:** Not available
- **summary:** CLOSED warning letter citing 192.605(b)(1).
- **machine formats:** - **json:** https://regulus.evalyn.ai/document/phmsa-enforcement-32021002wl.json
- **markdown:** https://regulus.evalyn.ai/document/phmsa-enforcement-32021002wl.md
- **app url:** https://regulus.evalyn.ai/document/phmsa-enforcement-32021002wl
- **source url:** https://primis.phmsa.dot.gov/enforcement-data/case/32021002WL
**body:**

Warning Letter involving NORTHERN NATURAL GAS CO. PHMSA's enforcement data identifies the cited regulation as 192.605(b)(1). The case was opened on 2021-01-15 and is reported as closed as of 2021-01-15. Open the official case record for notices, responses, orders, and the latest status.

Official case documents:

32021002WL_Warning Letter_01152021_(20-192781).pdf: https://primis.phmsa.dot.gov/enforcement-documents/32021002WL/32021002WL_Warning%20Letter_01152021_(20-192781).pdf

32021002WL_Warning Letter_01152021_(20-192781)_text.pdf: https://primis.phmsa.dot.gov/enforcement-documents/32021002WL/32021002WL_Warning%20Letter_01152021_(20-192781)_text.pdf

32021002WL_Warning Letter_01152021_(20-192781)_text.pdf

WARNING LETTER
mark.hewett@nngco.com , Royce.ramsay@nngco.com , and
VIA ELECTRONIC MAIL TO: Jonathan.wolfgram@state.mn.us
January 15, 2021
Mr. Mark Hewett
President & CEO
Northern Natural Gas Co
1111 South 103rd Street
Omaha, NE 68124
CPF 3-2021-002-WL
Dear Mr. Hewett:
On September 30, 2020, a representative of the Minnesota Office of Pipeline Safety (MNOPS)
acting as an interstate agent for the Pipeline and Hazardous Materials Safety Administration
(PHMSA) pursuant to Chapter 601 of 49 United States Code (U.S.C.) conducted an investigation
of an overpressure event at the Hayward, MN town border station. The investigation was
initiated after the event was reported as a safety related condition.
As a result of the inspection, it is alleged that you have committed a probable violation of the
Pipeline Safety Regulations, Title 49, Code of Federal Regulations (CFR). The item inspected
and the probable violation is:
1. § 192.605 - Procedural manual for operations, maintenance, and emergencies.
(b) Maintenance and normal operations. The manual required by paragraph (a) of
this section must include procedures for the following, if applicable, to provide
safety during maintenance and operations.
(1) Operating, maintaining, and repairing the pipeline in accordance with each of
the requirements of this subpart and subpart M of this part.
Northern Natural Gas Company (NNG) did not have adequate procedures to maintain the
operating pressure under the maximum allowable operating pressure (MAOP) during the
off-loading of natural gas from a bottle tanker to a town border station. As a result, the
inlet piping to the Hayward MN town border station exceeded the MAOP.



2
On August 25, 2020, NNG was engaged in a replacement project on the mainline
upstream of the Hayward town border station tap. In order to facilitate the replacement
and not shut natural gas off to the town, NNG brought in natural gas bottle tankers to
temporarily maintain the distribution system for the city. While delivering the natural
gas from the tankers to the town border station, NNG personnel allowed the pressure to
go above the 500 psig MAOP to 667 psig. NNG’s gas control received alarms and
notified personnel on site who subsequently reduced the pressure to under the MAOP
which took approximately one hour. No other parts of the station or the downstream
distribution system was affected. After identifying the non-compliance, NNG took
documented actions to address the cause and corrected the non-compliances that
contributed to the issue including adding additional procedures for off-loading bottle
tankers and requalifying personnel for this task.
Under 49 U.S.C. § 60122 and 49 CFR § 190.223, you are subject to a civil penalty not to exceed
$218,647 per violation per day the violation persists, up to a maximum of $2,186,465 for a
related series of violations. For violation occurring on or after November 27, 2018 and before
July 31, 2019, the maximum penalty may not exceed $213,268 per violation per day, with a
maximum penalty not to exceed $2,132,679. For violation occurring on or after November 2,
2015 and before November 27, 2018, the maximum penalty may not exceed $209,002 per
violation per day, with a maximum penalty not to exceed $2,090,022. For violations occurring
prior to November 2, 2015, the maximum penalty may not exceed $200,000 per violation per
day, with a maximum penalty not to exceed $2,000,000 for a related series of violations. We
have reviewed the circumstances and supporting documents involved in this case, and have
decided not to conduct additional enforcement action or penalty assessment proceedings at this
time. We advise you to correct the item(s) identified in this letter. Failure to do so will result in
Northern Natural Gas Company being subject to additional enforcement action.
No reply to this letter is required. If you choose to reply, in your correspondence please refer to
CPF 3-2021-002-WL. Be advised that all material you submit in response to this enforcement
action is subject to being made publicly available. If you believe that any portion of your
responsive material qualifies for confidential treatment under 5 U.S.C. 552(b), along with the
complete original document you must provide a second copy of the document with the portions
you believe qualify for confidential treatment redacted and an explanation of why you believe
the redacted information qualifies for confidential treatment under 5 U.S.C. 552(b).
Sincerely,
Gregory A. Ochs
Director, Central Region, Office of Pipeline Safety
Pipeline and Hazardous Materials Safety Administration
Cc: Royce Ramsay, Vice President, Operations, Royce.ramsay@nngco.com
Jonathan Wolfgram, Chief Engineer, MNOPS, Jonathan.wolfgram@state.mn.us
- **truncated:** false
- **body characters:** 5473
