ERW in the Southeastern US: Pilot Learnings and What’s Next

Today, we’re excited to have issued 1,602.80 high-quality credits on the Isometric registry, rooted in Lithos’ rigorous, industry-leading MRV.

These tons, captured by superfine byproduct rockdust spread in the opening months of 2024, represent some of our earliest Pilot deployments in the Southeastern U.S. region, and approximately 4,000 soil samples. The tons will be delivered to Frontier buyers and mark our first Isometric issuance.

We’re grateful to the partners who helped make this milestone for distributed, low-cost ERW possible:

• 🚀 The Frontier team and Frontier buyers who have catalyzed this early-stage VCM market

• 🧑🌾🚚🪨 Generational farmers who trusted us with their land, countless local businesses who supported operations in-field, and our incredible local quarry partner

• 📚 Dozens of academic researchers who have contributed to the field and to the work that Lithos is based on

• 👷 Our incredible Field Ops and Science teams who executed under first-of-a-kind, at-scale conditions and encountered novel challenges at every corner

How Pilot Data Connects to Learning Curves

We have a number of additional batches that will be released in the coming few weeks. In the meantime, with this Isometric certification of our earliest pilot tons, we wanted to reflect on what we’ve learned scaling from these first 50,000 tons of rockdust to now spreading over 670,000 tons of material across working farmland throughout America.

From the beginning, Lithos’s focus has been on building low-cost, scientifically-rigorous, and transparent ERW powered by community-centered supply chains with a clear ability to scale to megatons of carbon removal for <$100 per ton.

And in the early innings of ERW, data is what matters most. For us, it’s what enables the best deployment decisions, accelerates our operational learning curve, and builds the trust needed to help the field grow.

In that spirit, we want to share key learnings from these 2024 Pilots and how they’ve shaped our commercial-scale 2025 deployments in the same region.

What’s different from our Pilot tons to today

The short answer is: quite a lot. ERW is a young field, and the gap between a Pilot deployment and a commercial-scale operation is where most of the real engineering happens. We’re excited to have contributed many learnings to registry protocols via public commentary, and are excited by the latest versions of those protocols (including Isometric ERW V1.2 and Puro V2025). Here are learnings that are important as ERW continues to scale.

Real-world farming. ERW that doesn't survive contact with real farming isn't really ERW.

• MRV and operations have to work alongside real working farms, not against them.
• Farmers are deeply invested in this work.
• Farmers are excited about receiving their Lithos-generated agronomic data reports, soil health improvements, and high-quality sampling at frequencies they’d rarely see otherwise.
• Though we don’t pay growers directly to participate in our growing hubs, they participate because agronomic and soil-health benefits matter to them.
• That alignment is what makes ERW sustainable on real farmland.
• This also means MRV has to be resilient to tillage cycles, farmers’ on-the-fly material inputs, and the occasional land-ownership change that affects continued sampling access. The earliest 2024 Pilots taught us that we have to design for all of that and expect it to be a core part of empirical MRV at-scale.
• We now treat farming integration as a first-class influence on MRV rather than solely a downstream concern.

Severe Climatic Events. 2024 was a hard year for the Southeast.

• Historic summer drought stretched across much of the region, which meant less rainfall on our fields for the first 4-6 months, and slower weathering rates in that particular period.
• However, in the fall, Hurricane Helene saturated fields, recovering annual precipitation levels.
• The Hurricane also knocked over crops and farming infrastructure across the region, delaying harvest and ability to access fields for sampling.
• We learned that scale, diverse soil types and crops, and multi-county and multi-region operations let us absorb localized disruptions and keep deliveries on track even when individual sites are paused.

Standardizing field methods. Our earliest Pilots used several sampling techniques, calibrated to match local agronomic practices.

• What we learned is that uniformity beats local accommodation when the goal is scale and lower uncertainty.
• We’ve moved to a proprietary, uniform sampling technique that produces cleaner data across sites, with less noise to disentangle later.
• The same principle applies to GPS quality and pairing for our samples, taken at ~2.5 acre density. Standard phone GPS is only accurate to roughly 3 meters, which isn’t tight enough for rigorous pairing of treatment and control samples.
• We’ve moved to specialized hardware, carefully QCed every few weeks, and other applications that get us to the precision the science actually needs.

Geochemical lab QA/QC. Early in our Pilot work, we relied on smaller labs and built out our own bench capacity to fill the gaps.

• As volumes grew, we built a warehouse-based ERW Research Lab and developed deep partnerships with at-scale geochemical labs.
• At commercial scale, lab QA/QC stops being a back-office function and becomes a primary lever for uncertainty reduction. We treat it that way now.

Rock and soil matching at scale. With a dataset that now includes over 400,000 soil cores, we can predict more accurately which combinations of feedstock, crop, and soil type are most likely to produce both higher yields for growers and faster weathering rates for more tCDR.

• This is one of the quieter advantages of operating at scale.
• Every site we deploy makes the next one better. That compounding is one of the real reasons scale matters in this field.

Secondary validation. ERW secondary validation is a deep area of interest, and we’ve tested most of the techniques the field has proposed: gas flux measurements (now published), resin sampling, rhizons, lysimeters, and several newer approaches.

• Much of this work on our farms is going into publication this year. Stay tuned!
• None of these various secondary validations are meant to exactly match the repeatability of solid-phase measurements.
• Interestingly, Isometric V1.2 reflects this reality by making secondary validation optional, a meaningful update that aligns the protocol with where the science on multi-phase measurement actually stands.
• We continue to believe secondary measurements is a critical path for ongoing ERW work, and are excited to continue this work, especially in novel watershed/catchment level validation using specialized isotopes.
• In the meantime, see also Milliken et al. (2025).

Working alongside registries. We are encouraged to see more registries and third-party certification bodies/inspectors coming online to support ERW as the market matures! This is an important signal of both scientific progress and the broader commercialization of durable carbon removal.

• Many early ERW protocols were necessarily shaped around the field’s earliest datasets and pilot-scale deployments. As larger commercial datasets continue to emerge, protocols can increasingly evolve to reflect the operational realities, statistical power, and empirical learning curves of scaled deployments — like those operated by Lithos!
• We have been excited to see how registries and methodologies have continued improving alongside the field itself. We are grateful to the academic researchers, registry teams, validators, and buyer partners contributing to this work, and look forward to continued collaboration as ERW measurement and certification standards mature over time.

What you can expect from Lithos next

In the coming months, expect:

• Half a dozen additional commercial-scale deliveries. Built on the standardization and MRV improvements above, with raw cation sample data and geospatial pairing information included directly in registry artifacts.

• Peer-reviewed publications. As the largest deployer of Enhanced Rock Weathering today, we’re publishing alongside academic collaborators at leading research institutions. These papers will include large, multi-phase data sets from large-scale field deployments, the kind of empirical grounding the field has been waiting for.

• New watershed/catchment-level monitoring. Extending MRV beyond the field to the broader hydrological system.

More to share soon.

– The Lithos Team

Removed carbon is tracked from the farm to rivers and the oceans, monitoring for permanence and additionality.