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U.S. Department of Transportation U.S. Department of Transportation Icon United States Department of Transportation United States Department of Transportation

Interpretation Response #PI-19-0001

Below is the interpretation response detail and a list of regulations sections applicable to this response.

Interpretation Response Details

Response Publish Date:

Company Name: Town of Hopkinton

Individual Name: Mr. J. Raymond Miyares

Location State: MA Country: US

View the Interpretation Document

Response text:

Mr. J. Raymond Miyares
Town Counsel
Town of Hopkinton
40 Grove Street
Suite 190
Wellesley, MA 02482

Dear Mr. Miyares:

In a December 17, 2018, letter to the Pipeline and Hazardous Materials Safety Administration (PHMSA), you requested an interpretation of 49 CFR §§ 193.2005 and 193.2051. Specifically, you asked if lengthening an existing liquefied natural gas (LNG) facility's piping would be subject to 49 CFR Part 193, Subpart B regulations.


According to your letter, Hopkinton LNG Corp.(HOPCo) owns a peak-shaving LNG plant in the Town of Hopkinton, Massachusetts (Hopkinton LNG Plant). The Hopkinton LNG Plant has three cryogenic LNG storage tanks, with associated vaporizer and liquefaction facilities. The plant is sited on two parcels of land that straddle Wilson Street, a public roadway in Hopkinton. The existing liquefaction and vaporizer facilities are connected to the three LNG storage tanks through two pipes that cross Wilson Street through a below-grade, concrete culvert perpendicular to and under the Wilson Street roadway. The piping enters the culvert a short distance from the roadway on the eastern parcel, travels through the culvert below the roadway, and exits the culvert a short distance from the roadway on the western parcel. At the entry points for the culvert on the east side of the roadway, the piping changes direction in an approximately 90° turn twice - 90° downward until reaching the grade of the culvert and then 90° to run parallel to the culvert floor. At both the east-side entry point and west-side exist point, the piping is protected by metal fencing, boulders, concrete jersey barriers, and guardrails. Outside of the culvert, the pipes are suspended a short height above-grade, on concrete sleepers.

You indicated that HOPCo proposes to replace the plant's liquefaction facilities as part of an upgrade to the plant. That replacement project will remove the current liquefaction facilities on the eastern parcel and replace them with new liquefaction facilities on the western parcel. The plant's existing vaporization facilities, however, will remain on the eastern parcel. Accordingly, the two pipes crossing Wilson Street will remain in place and will continue to transport LNG between facilities on the two parcels.

As HOPCo replaces equipment at its LNG facility, you also want HOPCo to lengthen the distance between the roadway and the two pipes' entry and exit points. You believe this action would push the above-ground length of the piping farther back from the roadway to lessen the possibility of accidental vehicle strikes to the pipes. You further indicated that this proposal would not move the existing piping from its current route between the existing vaporizer and liquefaction facilities. Rather, it would entail lengthening the below-grade culvert and shifting the 90-degree piping turns farther back from the roadway an equal distance. Finally, you provided photos of the site and mentioned HOPCo's previous modifications to the plant's existing vaporizer, which were not subject to the Part 193 siting requirements.

PHMSA also received a March 11, 2019, letter from HOPCo, which indicated that the company believes that the Town's proposed modification to the Hopkinton LNG Plant, which went into service in the early 1970s, would likely require compliance with the Subpart B, Part 193 siting requirements. Specifically, HOPCo stated that at least some portion of the piping would need to be lowered as part of the Town's proposal, and that lowering appears to qualify as a relocation of an existing LNG facility (whether in terms of elevation from the ground or distance from plant property lines or other LNG facilities) under the Part 193 regulations. HOPCo further indicated that the Town's proposal would also require the installation of at least some new LNG piping.

PHMSA shared this letter with you on April 1, 2019, via email, and you responded on April 22, 2019, indicating that you had no amendments to your request for interpretation based on HOPCo's March 11, 2019 letter.


Would the Town of Hopkinton's proposed enhancement to the existing LNG pipelines at the Hopkinton LNG plant constitute the replacement, relocation or significant alteration of the facility within the meaning of 49 CFR §§ 193.2005(b) and 193.2051 and, therefore, be subject to siting requirements of 49 CFR Part 193, Subpart B?


PHMSA prescribes minimum Federal safety standards for the design, construction, operation, maintenance, and security of LNG facilities. PHMSA has promulgated regulations that govern the applicability of the siting requirements to existing LNG facilities. In particular, § 193.2005(b) states "[I]f an existing LNG facility (or facility under construction before March 31, 2000) is replaced, relocated or significantly altered after March 31, 2000, the facility must comply with the applicable requirements of this part governing, siting, design, installation, and construction ..." Additionally, § 193.2051 states "[E]ach LNG facility designed, constructed, replaced, relocated or significantly altered after March 31, 2000, must be provided with siting requirements in accordance with the requirements of this part and of NFPA 59A (incorporated by reference, see § 193.2013) ..."

1 See 49 USC §§ 60101(a)(1), (16), and 60103(c), providing that, with certain exceptions, a design, location, installation, construction, initial inspection, or initial testing standard prescribed after March 1, 1978, does not apply to an existing liquefied natural gas pipeline facility.

Based on the facts represented by the Town of Hopkinton, PHMSA does not consider the Town's proposed enhancement to the existing LNG pipelines at the Hopkinton LNG plant to constitute design, construction, replacement, relocation or significant alteration of the facility within the meaning of 49 CFR §§ 193.2005(b) and 193.2051. The existing LNG pipelines would remain in the same location and, therefore, would not be replaced or relocated. The change would also not constitute a significant alteration because the LNG operating parameters would not be affected by the proposed changes. Therefore, the proposed change in modifying the below-grade culvert and shifting the 90-degree piping turns farther back from the roadway would not be subject to the Subpart B, 49 CFR Part 193 siting requirements. However, if these existing LNG facilities are otherwise replaced, relocated, or significantly altered (by using new piping as suggested by HOPCo's March 11, 2019, letter), they may trigger the siting requirements under 49 CFR §§ 193.2005(b) and 193.2051.

Please keep in mind that this response letter reflects the agency's current application of the regulations to the specific facts you presented for clarification. Also, interpretations do not create legally-enforceable rights or obligations and are provided to help the requester understand how to comply with the regulations.

If we can be of further assistance, please contact Tewabe Asebe at 202-366-5523.

John A. Gale
Director, Office of Standards
and Rulemaking

Regulation Sections

Section Subject
193.2005 Applicability
193.2051 Scope