Submission Number: 966
Submission ID: 12651
Submission UUID: 2fa3b55b-857c-482f-8191-b1b36e93a180

Created: Wed, 06/12/2024 - 13:18
Completed: Wed, 06/12/2024 - 13:18
Changed: Thu, 06/13/2024 - 09:40

Remote IP address: 98.55.82.77
Submitted by: Anonymous
Language: English

Is draft: No

Flagged: Yes
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Submitted Comment
M. Stewart Salem
N/A
Proposed CI Score Queries

Oak Valley Energy, LLC seeks certification of two Tier 2 biomethane pathways from a dairy in Burley, Idaho: Oak Valley Dairy 1 & 4.

The provisional carbon-intensity scores for these proposed pathways are -407.68.

Having reviewed the information submitted to CARB, I would appreciate assistance understanding how a brownfield biogas project could achieve such a low carbon-intensity score. The first permits obtained for the dairy were issued by the Idaho Department of Environmental Quality in July 2006 (attached), which stated and required the farm be 100% dry lot until a new permit was obtained in 2021. A quick look on the historical satellite imagery from Google Earth shows that it continued to operate as a dry lot dairy until at least 2016--the feed lanes show manure scraping by heavy machinery. The then-extant lagoon was small and an ordinary dairy lagoon for milk parlor washout.

Dry lot dairies are near-optimal for avoidance of methane emissions since, unlike liquid effluent facilities, dry lot dairies capture volatile solids in the form of dried manure, which is then aerobically (and not anaerobically) composted to fertilizer which process does not release a material amount of methane.

As Oak Valley Dairy 1 & 4 was already relatively environmentally friendly in capturing and aerobically processing manure as a dry lot dairy until the covered digesters and lagoons were completed in 2021, the impressive proposed negative CI for Oak Valley scores raised my eyebrows.

Please could CARB help me understand the baseline scores used for Oak Valley Dairy 1 & 4 and how and why the CARB Staff Summary proposes CI scores which are less than -400 for a non-greenfield project, and if CARB Staff made a determination that Oak Valley was indeed a greenfield project notwithstanding its 15-years of operation as a dry lot?

In comparison, the proposed CI score of -407 is in stark relief against the -262 average CI score of all out-of-state dairy RNG projects certified by CARB and listed on its website. I am unsure whether this is the result of errata but I noticed a discrepancy for Oak Valley Dairy 1 & 4's life-cycle analysis spreadsheet adjustment for "Facility Specific Fugitive Methane from Upgrading" which states "On the EF table tab for both the Oak Valley 1&4 and Oak Valley 5 calculators, cell E86 was modified with the following formula “=1-(('Biogas-to-RNG'!V55+'Biogas-to-RNG'!U55)/'Biogas-to-RNG'!F55)” to quantify the facility specific fugitive methane from upgrading." while the Fugitive Methane from Upgrading in the List of Site-Specific Inputs states, "=MAX(IFERROR(1-(('Biogas-to-RNG'!V55+'Biogas-toRNG'!W55+'Biogas-to-RNG'!U55)/('Biogas-toRNG'!F55)),0),0.02)".

Thank you for your assistance.