# NORTHWEST NATURAL GAS CO — Warning Letter

**Citation:** CPF 120190003W  
**Type / status:** enforcement / historical  
**Agency:** Pipeline and Hazardous Materials Safety Administration  
**Effective:** Not stated  
**Published:** 2019-03-04

CLOSED warning letter citing 192.12(d).

## Document text

Warning Letter involving NORTHWEST NATURAL GAS CO. PHMSA's enforcement data identifies the cited regulation as 192.12(d). The case was opened on 2019-03-04 and is reported as closed as of 2019-03-04. Open the official case record for notices, responses, orders, and the latest status.

Official case documents:

120190003W_Warning Letter_03042019.pdf: https://primis.phmsa.dot.gov/enforcement-documents/120190003W/120190003W_Warning%20Letter_03042019.pdf

120190003W_Warning Letter_03042019_text.pdf: https://primis.phmsa.dot.gov/enforcement-documents/120190003W/120190003W_Warning%20Letter_03042019_text.pdf

120190003W_Warning Letter_03042019_text.pdf

WARNING LETTER
OVERNIGHT EXPRESS DELIVERY
March 4, 2019
Mr. Jon Huddleston
Vice President, Engineering and Utility Operations
Northwest Natural Gas Co
220 N.W. Second Avenue
Portland, OR 97209
CPF 1-2019-0003W
Dear Mr. Huddleston:
From October 30 through November 1, 2018, representatives of the Pipeline and Hazardous
Materials Safety Administration (PHMSA) pursuant to Chapter 601 of 49 United States Code
inspected Northwest Natural Gas Co’s (NWN) MIST Underground Natural Gas Storage Field
(MIST UGS Field). The inspection was was conducted at the NWN offices in Portland, Oregon
and the MIST UGS Field located 55 miles northwest of Portland in Columbia county, Oregon.
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 items inspected
and the probable violation(s) are:
1. § 192.12 (d) Underground natural gas storage facilities.
(d) Each underground natural gas storage facility that uses a depleted hydrocarbon
reservoir or an aquifer reservoir for gas storage, including those constructed not later
than July 18, 2017 must meet the operations, maintenance, integrity demonstration
and verification, monitoring, threat and hazard identification, assessment,
remediation, site security, emergency response and preparedness, and recordkeeping
requirements and recommendations of API RP 1171, sections 8, 9, 10, and 11
(incorporated by reference, see §192.7) by January 18, 2018.
NWN failed to meet the applicable requirements and recommendations of API RP 1171, section
10. Specifically, NWN did not have permanent weatherproof signs installed at the MIST UGS



CPF 1-2019-0003W
Field at each well site for identification purposes as required by API RP 1171, Section 10.4.1.
API RP 1171, Section 10.4.1, Minimum Signage Information, states in part:
Permanent weatherproof signage shall be installed at each well site for identification
purposes.
During the field inspection at the MIST UGS Field, PHMSA discovered that NWN did not have
permanent weatherproof signs installed at the following well sites:
 23adh-3
 33ac-3
 23ach-3
 33-3
 33d-3
 44-3
No reply to this letter is required. 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).
No reply to this letter is required. If you choose to reply, please submit all correspondence in this
matter to Robert Burrough, Director, PHMSA Eastern Region, 840 Bear Tavern Road, Suite 300,
West Trenton, NJ 08628. Please refer to CPF 1-2019-0003W on each document you submit, and
whenever possible provide a signed PDF copy in electronic format. Smaller files may be emailed
to robert.burrough@dot.gov. Larger files should be sent on a CD accompanied by the original
paper copy to the Eastern Region Office.
Sincerely,
Robert Burrough
Director, Eastern Region
Pipeline and Hazardous Materials Safety Administration
120190003W_Warning Letter_03042019_text Page 2 of 2

## Provenance

- Official: Yes
- Source: <https://primis.phmsa.dot.gov/enforcement-data/case/120190003W>
- Source ID: `phmsa-enforcement`
- SHA-256: `9e12c3f66f5bea4b1a570a6704527947b9772ddc4cb0de8ced51a28d001eb0b3`
- Retrieved: 2026-08-20T04:44:44.458Z
- Exported: 2026-08-25T08:28:25.526Z
- Document slug: `phmsa-enforcement-120190003w`

### Source metadata

```json
{
  "cpf": "120190003W",
  "operator": "NORTHWEST NATURAL GAS CO",
  "region": "Eastern",
  "pipelineType": "GAS INTRASTATE ONSHORE",
  "caseStatus": "CLOSED",
  "citedSections": [
    "192.12(d)"
  ],
  "dataAsOf": "08/04/2026 12PM",
  "caseDataAsOf": "2026-08-04",
  "attachmentCount": 2,
  "attachments": [
    {
      "name": "120190003W_Warning Letter_03042019.pdf",
      "url": "https://primis.phmsa.dot.gov/enforcement-documents/120190003W/120190003W_Warning%20Letter_03042019.pdf",
      "bytes": 154676,
      "category": "agency_document"
    },
    {
      "name": "120190003W_Warning Letter_03042019_text.pdf",
      "url": "https://primis.phmsa.dot.gov/enforcement-documents/120190003W/120190003W_Warning%20Letter_03042019_text.pdf",
      "bytes": 110796,
      "category": "agency_document"
    }
  ],
  "extractedAgencyDocumentCount": 1,
  "attachmentPolicy": "Official attachment links are retained. Agency-issued documents may also include a verified local PDF and page-level text representation.",
  "jurisdiction": "US",
  "operatorName": "NORTHWEST NATURAL GAS CO"
}
```
