§1.1 — What This Report Measures

This Environmental Impact Review is a delta model. It measures the difference between two defined states:

State A — Current System: Hillsborough County continues its existing waste management trajectory — WTE processing at Reworld™ RRF capacity, overflow and non-processable waste routed to the Southeast County Landfill, biosolids composted at the SE Landfill or landfilled. Costs escalate structurally; no new infrastructure is in development.

State B — With Carbotura: A 30-year Circular Supply Agreement with the Carbotura SPV converts up to 2,000 TPD of manufacturing feedstock into industrial materials. Under the CSA, the county pays a Beneficiation Fee (TMC Fee) per ton delivered and receives Circular Royalty™ payments commencing Month 13 — two independent transactions. The Legacy Remediation Royalty is a CSA add-on that stacks alongside the Circular Royalty™ at no additional fee. Zero county capital is required.

State A is sourced from the Waste Study and locked Registry values. State B is sourced exclusively from the Proposal EIR Input Block. No values in this document are independently derived.

§1.2 — Decision Summary Table

§1.3 — Fiscal vs. Regional Economic Separation

§2.1 — Feedstock Volume and Disposition

§2.2 — State A Cost Structure

§2.3 — State A Cost Trajectory

Three mechanisms drive State A cost escalation — all documented in the Waste Study: (1) population growth adding ~400 new waste customers per month at 3%+ annual tonnage growth; (2) capital reinvestment pressure at the 162-acre Southeast County Landfill, where cell elevation expansion is already underway; and (3) absence of any competing disposal alternative in the county's planning horizon through 2065. State A escalation is structural and one-directional.

§2.4 — State A Environmental and Structural Position

State A sends approximately 730,000 TPY of the 2,000 TPD addressable volume to landfill and WTE combustion — generating an estimated 480,000 tonnes CO₂e per year from streams that ACM would otherwise process into industrial materials. The SE County Landfill's cell expansion further extends active landfill footprint on a 162-acre site with finite vertical capacity. PFAS contamination risk from biosolids under tightening federal standards represents a structural liability that increases in State A and diminishes in State B.

§3.1 — Inherited Flags

All State B values carry the same confidence classifications as the Proposal: phase capacities and COD dates are ESTIMATED; Beneficiation Fee (TMC Fee) and royalty parameters are Carbotura standard; P1 site address and rail access are VERIFIED. The FWDC planning basis of $95/ton (MODELED) governs all gross cost displacement calculations.

§3.2 — Deployment Configuration

§3.3 — Economic Terms (from Proposal EIR Input Block)

§3.4 — Residual Obligations

Under State B, Hillsborough County continues to operate its existing solid waste infrastructure for all volumes not covered by the ACM CSA. At Phase Initial (400 TPD), approximately 1,345 TPD of county-primary feedstock remains in the State A system. Phase Expanded (2,000 TPD) covers all identifiable Hillsborough County primary streams plus regional supplemental sourcing — residual county disposal obligation approaches zero for covered streams at full build-out.

§3.5 — Timeline Anchoring

All State B timelines originate from T0 = Q2 2026. Phase Initial COD of Q2 2028 represents T0 + 24 months using the Carbotura standard construction schedule. First Circular Royalty™ payment (July 2029) is T0 + 37 months. All timelines are ESTIMATED.

§4.1 — Three Delta Components

The fiscal delta between State A and State B consists of exactly three components that must be tracked separately:

1. Gross cost displacement: The reduction in disposal cost resulting from the Beneficiation Fee (TMC Fee) replacing the State A FWDC. At $100/ton Beneficiation Fee vs. $95/ton blended FWDC, the gross displacement is −$5/ton in Year 1 (slight additional cost vs. blended basis). Against stream-specific primary rate of $110/ton, displacement is +$10/ton from Year 1.
2. Circular Royalty™ cash flow: Revenue received by the county commencing Month 13, at 120% of that year's Beneficiation Fee escalating +1pp/year via multiplier mechanic. Independent transaction — paid from Carbotura product revenues. $120/ton in Year 2, growing annually.
3. Residual obligation: The continuing cost of managing waste volumes not covered by the CSA in the relevant phase. Declines to near-zero at Phase Expanded.

§4.1 — Phase-by-Phase Comparative Table

All figures ESTIMATED. Year 1: Beneficiation Fee paid · Royalty $0. Year 2+: Beneficiation Fee and Royalty are independent concurrent transactions. Residual disposal cost at State A rates for uncovered volumes.

§4.4 — 30-Year Gross Cost Displacement (Phase Initial)

State A FWDC escalated at 2%/yr (conservative). All ESTIMATED.

§4.5 — 30-Year Circular Royalty™ — Phase Initial

§5.1 — Employment Delta

⚑ Regional economic effects — not county fiscal receipts. These figures are not included in the fiscal flows reported above.

Scaled from Carbotura standard 400 TPD baseline parameters. Regional multipliers applied. Not a county fiscal receipt.

§5.2 — Environmental Delta

⚑ Designed-performance basis — actual performance subject to feedstock composition variability and operating conditions.

§5.3 — PFAS Structural Delta

Federal EPA PFAS standards under Part 503 are tightening. In State A, biosolids continue to be composted or landfilled — routes that face increasing regulatory scrutiny as PFAS contamination limits tighten. In State B, ACM thermomechanical conversion destroys organic contaminants including PFAS compounds at processing temperatures. The PFAS regulatory trajectory is a structural liability that compounds in State A and is eliminated in State B for covered biosolids streams.

§5.4 — No-Fallback Analysis

The Hillsborough County Solid Waste Master Plan (horizon 2065) contains no greenfield landfill siting. The WTE is operating at or near permitted capacity. There is no competing infrastructure in permitting, no regional waste disposal alternative at comparable cost, and no capital committed to structural disposal capacity expansion beyond cell elevation at the existing landfill. State A is not a stable equilibrium — it is a cost escalation trajectory without a relief mechanism. The absence of a fallback is itself a structural condition that increases the opportunity cost of delay.

§6.1 — Risk Register

§6.2 — Feedstock Variability ±20%

Per-ton Circular Royalty™ rate exceeds per-ton Beneficiation Fee in Year 2 across all volume scenarios; both are reported as separate transactions. The county's fiscal flows are robust to feedstock variability because royalty scales proportionally with Beneficiation Fee volume.

§6.3 — FWDC Sensitivity — Sign-Change Threshold

The gross cost displacement is negative at the blended FWDC of $95/ton (TMC $100 > FWDC $95). The gross displacement turns positive (savings) when the verified blended FWDC exceeds $100/ton — a condition that is met by the primary processable MSW stream alone ($110/ton). The sign-change threshold for gross displacement is FWDC = $100/ton. If the verified blended FWDC exceeds $100/ton, the county saves on disposal cost from Year 1 in addition to receiving royalties from Year 2. The Year 2+ per-ton Circular Royalty™ rate ($120/ton) exceeds the per-ton Beneficiation Fee ($102.50/ton in Year 2) at all volume levels; both are reported as separate transactions and never netted.

§6.4 — Royalty Escalator Sensitivity

Per-ton Circular Royalty™ rate exceeds per-ton Beneficiation Fee at Year 30 under all three escalator scenarios; both are reported as separate transactions. Even with zero escalation (flat 120% royalty), the per-ton royalty exceeds the per-ton fee throughout the term. All ESTIMATED.

§6.5 — Timeline Slippage

Additional pre-royalty cost = quarters delayed × ~$1,460,000 (quarterly TMC at Phase Initial vs. avoidable State A cost). The authorization deadline is within the county's direct control.

§7.1 — Binding Constraints

Two binding constraints define the Q3 2026 authorization deadline: (1) the Carbotura standard 24-month construction schedule from T0, which sets Q2 2028 as the earliest achievable Phase Initial COD if T0 is Q2 2026; and (2) the DCBC site's pre-approved heavy industrial designation, which provides the fastest available permitting path. Any delay in authorization directly delays T0, which directly delays COD and shifts the first royalty payment.

§7.2 — Decision Window Table

§7.4 — Optionality Matrix

§8.1 — Fiscal Obligations and Receipts

Beneficiation Fee and Circular Royalty™ are independent transactions shown gross. Royalty payments begin 13 months after corresponding Beneficiation Fee payments. All ESTIMATED.

§8.2 — Regional Economic Effects

⚑ These are regional economic effects, not county fiscal receipts. They are not included in the fiscal flows above.

Phase Expanded at 2,000 TPD generates an estimated ~155 direct FTE positions, ~465 indirect jobs, and ~$92.5M/year in regional economic impact in the Tampa Bay area. These represent newly-created manufacturing employment — not displaced service jobs — and are concentrated in the Pasco County industrial corridor, a historically under-resourced area with a documented 30% poverty rate in parts of the DCBC service zone.

§8.3 — Environmental Effects

⚑ Designed-performance basis — subject to feedstock composition variability.

Phase Expanded designed performance: ~800,000 tonnes CO₂e avoided annually, ~730,000 TPY diverted from landfill, ~290,000 m³/year ultrapure water recovered, ~475 GWh-equivalent annual energy output. PFAS risk eliminated for all covered biosolids streams.

§8.4 — Structural Effects

State B replaces a cost-escalation trajectory with a revenue-generating one. The county's role shifts from a passive disposer of waste — paying escalating fees for a resource that has no return — to a manufacturing feedstock supplier receiving a Circular Royalty™ that grows annually for 30 years. The structural position of Hillsborough County in its waste management system changes from cost center to industrial partner.

§8.5 — Unresolved Data Gaps