William,
Thank you for your continued engagement on the metering station design issues at the Wetzel County Interconnect. This email follows up on the discussions at the November 14, 2022 prehearing conference before ALJ Whitfield, as well as the subsequent informal exchanges between our respective clients' engineering teams. The purpose of this correspondence is to provide Ridgeline Natural Gas Pipeline Company's ("Ridgeline") technical clarifications on the proposed metering station design at the Wetzel County Interconnect, responding to the concerns raised in Appalachian Trunk Pipeline Company's ("ATPC") August 15, 2022 protest in FERC Docket No. RP22-847-001 regarding the alleged inadequacy of the receipt-point metering station design. The technical specifications discussed below are consistent with and reflected in Version 2.0 of the Draft Interconnection Agreement (December 2022 redline), which remains the current working draft between the parties.
**Ultrasonic Flow Meter Specifications**
Ridgeline proposes three (3) ultrasonic flow meter runs, each 12-inch diameter, at the Wetzel County Interconnect meter station. The meter station is located at Milepost 0.0 of the Ridgeline Pipeline System, tying into ATPC's existing 30-inch mainline at ATPC Milepost 412.6, at a receipt point in Wetzel County, West Virginia (approximate coordinates: 39.6120° N, 80.7540° W).
The three-run configuration provides both operational redundancy and measurement accuracy consistent with AGA Report No. 9 standards. I want to address directly ATPC's characterization in its protest that the metering design is "inadequate." The 12-inch meter runs are appropriately sized for the design capacity at the interconnect of 800 MMcf/d bidirectional flow, which is expandable to 1.2 Bcf/d with the addition of further meter runs as future volumes warrant. Current throughput on the Ridgeline system is approximately 680 MMcf/d, representing 56.67% utilization of the system's 1.2 Bcf/d design capacity. The 800 MMcf/d interconnect design capacity therefore comfortably accommodates both current volumes and near-term projected growth. Meter proving and calibration procedures are detailed in the attached revised schematics (Attachment 1).
**Gas Chromatograph Requirements**
Ridgeline proposes installation of dual online gas chromatographs — one primary and one backup — at the Wetzel County Interconnect. These chromatographs will provide real-time BTU content, specific gravity, and compositional analysis of gas flowing through the interconnect. Measurement will conform to AGA Report No. 8 and GPA 2261 standards. Data output from the chromatographs will feed directly into the SCADA system (discussed below) and will also be made available through Ridgeline's electronic bulletin board ("EBB") once the applicable tariff provisions are finalized.
These specifications are intended to address ATPC's stated concern regarding gas quality measurement at the interconnect. Dual chromatograph installations of this type are standard for interconnects of this capacity throughout the Appalachian Basin, and we believe this configuration should resolve any questions about the adequacy of gas quality monitoring.
**SCADA Integration**
Ridgeline's SCADA system will be integrated with ATPC's existing SCADA network at the Wetzel County Interconnect. Real-time flow data, pressure readings, gas quality data, and operational alerts will be shared between the two systems on a continuous basis. We propose a communication protocol — likely Modbus TCP/IP or an equivalent industry-standard protocol — to be mutually agreed upon by the parties' respective engineering teams.
As you may be aware, the three compressor stations on the Ridgeline system — the Wetzel Station, Mannington Station, and Waynesburg Station, representing aggregate installed compression of 45,000 HP — are already fully SCADA-integrated. The interconnect meter station would be incorporated into this existing network. The pig launcher/receiver at the interconnect will also be SCADA-monitored.
**Design Capacity at Interconnect**
To reiterate, the proposed interconnection design capacity is 800 MMcf/d bidirectional, expandable to 1.2 Bcf/d. For context, ATPC's system capacity is 3.8 Bcf/d across its 640-mile system; the interconnect volumes therefore represent a manageable proportion of ATPC's overall throughput. The Ridgeline Pipeline System itself is a 187-mile, 24-inch-diameter high-pressure natural gas pipeline extending from the Wetzel County Interconnect receipt point to the Waynesburg Compressor Station delivery point in Greene County, Pennsylvania (approximate coordinates: 39.8965° N, 80.1810° W).
**Interconnection Cost Allocation**
The revised schematics attached hereto reflect the metering station design as currently scoped in the $22.3 million total interconnection facilities cost estimate. Ridgeline maintains its proposed cost allocation as set forth in the Draft Interconnection Agreement: $7.6 million to Ridgeline (34.1%) and $14.7 million to ATPC (65.9%). We acknowledge ATPC's advocacy for a 50/50 allocation ($11.15 million each), but I will not engage in extended argument on that point here. Our position on cost allocation was addressed in Ridgeline's answer to the ATPC protest filed October 17, 2022, and in George Trujillo's separate November 2022 letter to your firm regarding the counterproposal on metering station design. I would simply note that the parties should remain mindful that the interconnection agreement terms may ultimately require FERC approval as part of the tariff proceeding, and both sides' interests are served by reaching a commercially reasonable resolution on this issue in advance of any such filing.
**Attachments**
Enclosed with this email please find:
- **Attachment 1:** Revised Metering Station Schematics — Wetzel County Interconnect (December 2022) — PDF engineering drawings showing the layout of the three ultrasonic flow meter runs, dual gas chromatographs, pig launcher/receiver, and SCADA interface points. - **Attachment 2:** Ultrasonic Flow Meter Technical Specifications — Summary Sheet — a one-page summary of meter manufacturer specifications, flow range, accuracy tolerances, and proving requirements.
The schematics incorporate modifications discussed informally between Thomas Greaves, Ridgeline's Vice President of Engineering & Operations, and ATPC's engineering team during their recent exchanges.
**Next Steps**
We would like to propose scheduling a technical call in early January 2023 between Ridgeline's engineering team, led by Mr. Greaves, and ATPC's representatives — including Sandra and ATPC's engineers — to walk through the revised schematics in detail. As you know, Ridgeline's direct testimony, including the pre-filed testimony of Thomas Greaves on engineering and system design, was filed on December 5, 2022, and provides additional context on these specifications. We are happy to circulate a proposed agenda for the call once we have agreement on a date and time.
Ridgeline remains committed to resolving the metering design issues cooperatively in advance of the hearing schedule established by ALJ Whitfield. We believe the specifications outlined above demonstrate that the proposed metering station design is robust, industry-standard, and fully adequate for the interconnect as designed. We look forward to your and Sandra's feedback.
Best regards,
Brett Callahan
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**Brett Callahan** Associate **Calderwood & Harkness LLP** 1601 K Street NW, Suite 900 Washington, DC 20006 Tel: (202) 555-4218 Email: bcallahan@calderwoodharkness.com
C&H Matter No. 1016-00005 FERC Docket Nos. RP22-847-000 / RP22-847-001
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